Advertisement

Three Decades of Research: The Case for Comprehensive Sex Education

Open AccessPublished:October 12, 2020DOI:https://doi.org/10.1016/j.jadohealth.2020.07.036

      Abstract

      Purpose

      School-based sex education plays a vital role in the sexual health and well-being of young people. Little is known, however, about the effectiveness of efforts beyond pregnancy and sexually transmitted disease prevention. The authors conducted a systematic literature review of three decades of research on school-based programs to find evidence for the effectiveness of comprehensive sex education.

      Methods

      Researchers searched the ERIC, PsycINFO, and MEDLINE. The research team identified papers meeting the systematic literature review criteria. Of 8,058 relevant articles, 218 met specific review criteria. More than 80% focused solely on pregnancy and disease prevention and were excluded, leaving 39. In the next phase, researchers expanded criteria to studies outside the U.S. to identify evidence reflecting the full range of topic areas. Eighty articles constituted the final review.

      Results

      Outcomes include appreciation of sexual diversity, dating and intimate partner violence prevention, development of healthy relationships, prevention of child sex abuse, improved social/emotional learning, and increased media literacy. Substantial evidence supports sex education beginning in elementary school, that is scaffolded and of longer duration, as well as LGBTQ–inclusive education across the school curriculum and a social justice approach to healthy sexuality.

      Conclusions

      Review of the literature of the past three decades provides strong support for comprehensive sex education across a range of topics and grade levels. Results provide evidence for the effectiveness of approaches that address a broad definition of sexual health and take positive, affirming, inclusive approaches to human sexuality. Findings strengthen justification for the widespread adoption of the National Sex Education Standards.

      Keywords

      Implications and Contribution
      Attention to the full range of sexual health topics, scaffolded across grades, embedded in supportive school environments and across subject areas, has the potential to improve sexual, social, and emotional health and academic outcomes for young people.
      See Related Editorial on p.7
      Public health practitioners and policy-makers have long considered school-based sex education to play a vital role in the sexual health and well-being of young people. Likewise, surveys of the public over several decades have consistently shown strong support for comprehensive sex education (CSE; also known as comprehensive sexuality education) [
      Planned Parenthood Federation of America
      Sex education: A national survey on support among likely voters.
      ]. Nevertheless, except for evaluations of sexually transmitted infection (STI) and pregnancy prevention programs, not enough is known about the effectiveness of sex education efforts, which have the potential to influence adolescent health in a variety of ways. This paper describes the results of a literature review of three decades of research on the effectiveness of school-based programs, from both the U.S. and around the world, that focus on a range of outcomes associated with CSE.

      Background

      Sex education has long been characterized by competing definitions, goals, and philosophies, which has muddied efforts to understand and gauge its effectiveness [
      • Goldfarb E.S.
      A crisis of identity in sexuality education in America: How did we get here and where are we going?.
      ]. When it comes to measuring impact and outcomes, research has been dominated by interest in prevention programs aimed at reducing STI and pregnancy rates [
      • Trenholm C.
      • Devaney B.
      • Fortson K.
      • et al.
      Impacts of abstinence education on teen sexual activity, risk of pregnancy, and risk of sexually transmitted diseases.
      ,
      • Kirby D.
      Emerging answers: Research findings on programs to reduce teen pregnancy (summary).
      ,
      • Sales J.M.
      • Milhausen R.R.
      • DiClemente R.J.
      A decade in review: Building on the experiences of past adolescent STI/HIV interventions to optimise future prevention efforts.
      ,
      • DiClemente R.J.
      • Crittenden C.P.
      • Rose E.
      • et al.
      Psychosocial predictors of HIV-associated sexual behaviors and the efficacy of prevention interventions in adolescents at-risk for HIV infection: What works and what doesn’t work?.
      ,
      • Card J.J.
      • Lessard L.
      • Benner T.
      PASHA: Facilitating the replication and use of effective adolescent pregnancy and STI/HIV prevention programs.
      ,
      • Robin L.
      • Dittus P.
      • Whitaker D.
      • et al.
      Behavioral interventions to reduce incidence of HIV, STD, and pregnancy among adolescents: A decade in review.
      ,
      • Guse K.
      • Levine D.
      • Martins S.
      • et al.
      Interventions using new digital media to improve adolescent sexual health: A systematic review.
      ]. These prevention programs put emphasis on sexual behaviors and behavior change as the main focus of analysis [
      • Goldfarb E.S.
      • Constantine N.A.
      Sexuality education.
      ]. What has remained largely unstudied, however, are approaches with a broader and more comprehensive focus on human sexuality, defined by SIECUS as:
      “…the sexual knowledge, beliefs, attitudes, values, and behaviors of individuals. Its various dimensions involve the anatomy, physiology, and biochemistry of the sexual response system; identity, orientation, roles, and personality; and thoughts, feelings, and relationships” [
      SIECUS
      Position statements. [PDF]. 2018.
      ].
      In 2012, the Future of Sex Education, a partnership among three leading national sex education organizations, Advocates for Youth, Answer, and SIECUS, released the National Sexuality Education Standards (NSES) [
      Future of Sex Education Initiative
      National sexuality education standards: Core content and skills, K-12.
      ]. These were updated in 2020, as the National Sex Education Standards, Second Edition [
      Future of Sex Education Initiative
      National sex education standards: Core content and skills, K-12.
      ]. The goal of the NSES is to provide school districts with “clear, consistent, and straightforward guidance on the essential, minimum, core content, and skills needed for sex education that is age-appropriate for students in Grades K-12 to be effective” [
      Future of Sex Education Initiative
      National sex education standards: Core content and skills, K-12.
      ]. It consists of the following seven topic areas: Consent and Healthy Relationships, Anatomy and Physiology, Puberty & Adolescent Sexual Development, Gender Identity and Expression, Sexual Orientation and Identity, Sexual Health, and Interpersonal Violence [
      Future of Sex Education Initiative
      National sex education standards: Core content and skills, K-12.
      ].
      Since the initial publication of the NSES, school districts across the country have been relying on these standards to develop and implement CSE, with recent data suggesting that more than 40% of districts in the U.S. have adopted the NSES [
      Centers for Disease Control and Prevention
      Results from the school health policies and practices study 2016.
      ]. Along with increasing dependence on the NSES has come growing and renewed interest in the evidence that supports their use.

      Methods

      The authors conducted a Systematic Literature Review (SLR) dating back to 1990 to find evidence for the effectiveness of CSE. The year 1990 represents a fundamental shift in the field of sex education as evidenced by the publication in 1991 of the SIECUS Guidelines for Comprehensive Sexuality Education Kindergarten through 12th Grade [
      SIECUS
      Guidelines for comprehensive sexuality education: Kindergarten-12th grade.
      ]. The Guidelines provided the first national framework for the concepts, topics, and skills that should be taught to young people at different ages and grade levels. As such, they were the precursor to the NSES and can justifiably be seen as representing the beginning of the “modern era” of CSE.
      The SLR was designed to cast a wide and inclusive net to assure that all aspects of CSE were included. The criteria for the initial search were as follows: (1) qualitative or quantitative studies evaluating outcomes of school-based, K-12 educational approaches; (2) both within sex education and across the curriculum; and (3) that were U.S. based.
      In consultation with the research team, an information specialist, experienced in SLR searches, developed and tested the strategy using an iterative process. ERIC and PsycINFO were searched on the Ebsco platform, as well as MEDLINE on Web of Science. All searches were performed on December 14, 2017. Strategies used a combination of controlled vocabulary (e.g., “Sex Education,” “Schools,” and “Sexual Health”) and keywords (e.g., “curriculum,” “K-12,” and “LGBTQ”; the search terms included both common acronyms [e.g., LGBTQ and STI] as well as the individual words [e.g., LGBTQ, sexually transmitted infections, etc.]). The initial list of terms was derived from the 2012 NSES. The research team added terms they deemed important based on their expertise in the field of sex education, and then the entire list was reviewed independently by an outside group of sex education experts for accuracy and thoroughness. Vocabulary and syntax were adjusted across the selected databases. All searches were limited to the English language.
      A team of four graduate research assistants and the authors reviewed the first 1,500 records to develop and refine the coding strategy. Using article title and abstract, a coding scheme was developed: (1) articles that met the specified criteria for the SLR; (2) articles that needed further review to determine eligibility (and then recoded accordingly); (3) articles that were completely unrelated to the subject and eliminated. With an eye toward potential expansion of the review, two additional categories were coded: (4) articles that were non-U.S. based, but otherwise met the inclusion criteria; and (5) articles that were related to the topic of sex education, but did not meet the specified criteria.
      Next, in teams of two, research assistants coded the remaining records. After scoring them independently, partners met to compare codes. Interrater reliability for papers coded 1 or 2 was calculated after review of 25% of the records, with 96% agreement for both of the teams. The lead researchers were called on to reconcile differences.
      The search results are summarized in the PRISMA diagram [
      • Liberati A.
      • Altman D.G.
      • Tetzlaff J.
      • et al.
      The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: Explanation and elaboration.
      ] (Figure 1). Because the search intentionally identified material that broadly met the concepts of CSE, the initial result included more than 46,000 records, deduplicated to 42,447. After eliminating articles that were completely unrelated to the topic, 8,058 papers remained. Among those, 481 met the initial criteria for the SLR, 2,094 were non-U.S. based, and 5,483 were related to sex education, but were not school-based evaluations. These 481 papers, plus 50 additional articles from review of references, were read in full text, resulting in 218 remaining in the “1” category. Among those, 179 focused solely on pregnancy and disease prevention approaches, and 39 focused on other CSE topics delineated in the NSES. Given the breadth and sheer number of studies, and in the interest of drawing conclusions about the broader impact of CSE, the researchers decided to exclude studies focused only on pregnancy and disease prevention programs. The ample literature reflecting the effectiveness of sex education in helping young people lower their risk of unplanned pregnancy, STIs, and HIV is the subject of another article.
      Figure thumbnail gr1
      Figure 1PRISMA diagram of the literature search.
      In the next phase of the review, the team expanded the criteria to include evaluation studies that were coded as 4 (non-U.S.) or 5 (related to CSE, such as school-wide initiatives) and also met review criteria as evaluation studies of school-based programs. After completion of this process, two research assistants conducted a targeted online search of the literature, excluding pregnancy and STI prevention studies, for research published after the initial search was conducted through November 2019. A total of 80 articles constitute the final set for this review.
      The researchers identified the outcomes in each study and then sorted those outcomes into several overarching categories based on commonly identified aims of CSE. These were identified as appreciation of sexual diversity, dating and intimate partner violence (IPV) prevention, development of healthy relationships, and prevention of child sex abuse. Within these overarching categories, several subtopics emerged that correspond with widely recognized goals of CSE [
      • Goldfarb E.S.
      • Constantine N.A.
      Sexuality education.
      ,
      SIECUS
      Position statements. [PDF]. 2018.
      ,
      Future of Sex Education Initiative
      National sex education standards: Core content and skills, K-12.
      ,
      SIECUS
      Guidelines for comprehensive sexuality education: Kindergarten-12th grade.
      ]. Figure 2 identifies the number of outcomes reported for each overarching category. Several studies were counted in more than one category.

      Results

      The studies that form the basis of this review vary widely in their size, rigor of analysis, and generalizability of findings. They include methodologically strong studies, using quasi-experimental or experimental designs, as well as meta-analyses and SLRs. They also include a substantial number of studies with less rigorous designs, smaller samples, and/or more qualitatively based approaches that when taken together lead to strong evidence of outcomes. Table 1 provides details for the outcome studies reviewed here including methodology and alignment of outcomes with the NSES topic areas [
      Future of Sex Education Initiative
      National sex education standards: Core content and skills, K-12.
      ].
      Table 1Details about outcome studies identified in the review
      Authors and ReferencesYearCountryStudy population and sizeStudy designOutcome sub-topics
      Outcome Subtopics:Appreciation of sexual diversity: 1 = lower homophobia; 2 = reduced homophobic bullying; 3 = expanded understanding of gender/gender norms; 4 = recognition of gender equity, rights, social justice.Dating and intimate partner violence: 5 = improved knowledge and attitudes about, and reporting of, sexual and intimate partner violence; 6 = decreased sexual and intimate partner violence perpetration and victimization; 7 = increased bystander intentions and behaviors.Healthy relationships: 8 = increased relationship knowledge, attitudes, and skills; 9 = improved communication skills and intentions.Child sex abuse: 10 = improved knowledge, attitudes, skills, and social–emotional outcomes related to personal safety and touch; 11 = improved disclosure skills and behaviors.Additional outcomes: 12 = social–emotional learning; 13 = media literacy.
      Corresponding NSES topic
      Schall and Kauffmann [
      • Schall J.
      • Kauffmann G.
      Exploring literature with gay and lesbian characters in the elementary school.
      ]
      2003USA29; 4th and 5th gradersQualitative, class discussion1, 3SO
      Eick et al. [
      • Eick U.
      • Rubinstein T.
      • Hertz S.
      • Slater A.
      Changing attitudes of high school students in Israel toward homosexuality.
      ]
      2016Israel272; 9th to 11th graders and three high schoolsNonexperimental, paired pre- and post-test1, 3SO
      Richard et al. [
      • Richard G.
      • Vallerand O.
      • Petit M.P.
      • Charbonneau A.
      Discussing sexual orientation and gender in classrooms: A testimonial-based approach to fighting homophobia in schools.
      ]
      2015Canada277; 9th to 12th gradersNonexperimental, paired pre- and post-tests1, 2, 13SO, GI
      Athanases [
      • Athanases S.Z.
      A gay-themed lesson in an ethnic literature curriculum: Tenth graders' responses to `Dear Anita'.
      ]
      1996USA21; 10th gradersQualitative, class discussion, and interviews1, 3, 5, 13SO
      Van de Ven [
      • Van de Ven P.
      Effects on high school students of a teaching module for reducing homophobia.
      ]
      1995Australia130; 9th gradersNonexperimental, pre- and post-test with 3-month follow-up1SO
      Helmer [
      • Helmer K.
      "Everyone needs a class like this": High school students' perspectives on a gay and lesbian literature course.
      ]
      2015USA24; 11th and 12th gradersQualitative, student questionnaires and interviews1, 3, 5SO, GI
      Helmer [
      • Helmer K.
      Gay and lesbian literature disrupting the heteronormative space of the high school English classroom.
      ]
      2016USA24; 11th and 12th gradersQualitative, ethnographic student and teacher interviews, observations and artifacts1, 3, 5SO, GI
      Alan and Miriam [
      • Alan H.
      • Miriam I.
      LGBTQ youth in american schools: Moving to the middle.
      ]
      2011USA1,613 students and 19 staff members, middle schoolsMixed methods, nonexperimental student surveys, staff focus groups3SO
      Bentley and Souto-Manning [
      • Bentley D.F.
      • Souto-Manning M.
      Toward inclusive understandings of marriage in an early childhood classroom: Negotiating (un)readiness, community, and vulnerability through a critical reading of "King and King".
      ]
      2016USA1 preschool classQualitative, class discussion3, 4, 5SO
      Lucassen and Burford [
      • Lucassen M.F.
      • Burford J.
      Educating for diversity: An evaluation of a sexuality diversity workshop to address secondary school bullying.
      ]
      2015New Zealand229; 9th and 10th graders (aged 12–15 years)Nonexperimental, paired pre- and post-tests3, 13SO
      Brown et al. [
      • Brown L.K.
      • Barone V.J.
      • Fritz G.K.
      • et al.
      AIDS education: The Rhode Island experience.
      ]
      1991USA2,709; 7th to 12th gradersExperimental, pre- and post-test3, 4SO
      Snapp et al. [
      • Snapp S.D.
      • McGuire J.K.
      • Sinclair K.O.
      • et al.
      LGBTQ-inclusive curricula: Why supportive curricula matter.
      ]
      2015USA1,232 high school and middle school students (aged 12–18 years)Qualitative survey2SO
      Baams et al. [
      • Baams L.
      • Dubas J.
      • van Aken M.
      Comprehensive sexuality education as a longitudinal predictor of LGBTQ name-calling and perceived willingness to intervene in school.
      ]
      2017The Netherlands601; 10th to 12th gradersQuasi-experimental, longitudinal, surveys2SO, GI
      Proulx et al. [
      • Proulx C.N.
      • Coulter R.W.
      • Egan J.E.
      • et al.
      Associations of lesbian, gay, bisexual, transgender, and questioning-inclusive sex education with mental health outcomes and school-based victimization in U.S. high school students.
      ]
      2019USA47,000; 9th to 12th graders, from 11 statesMultilevel modeling of YRBS and School Health Profiles2SO
      Blake et al. [
      • Blake S.M.
      • Ledsky R.
      • Lehman T.
      • et al.
      Preventing sexual risk behaviors among gay, lesbian, and bisexual adolescents: The benefits of gay-sensitive HIV instruction in schools.
      ]
      2001USA3,647; 9th to 12th gradersMultistage cluster sample from 63 schools, YRBS data2SO
      Hill and Kearl [
      • Hill C.A.
      • Kearl H.
      Crossing the line: Sexual harassment at school.
      ]
      2011USA1,965; 7th to 12th gradersQualitative, survey4GI
      Ramirez-Valles et al. [
      • Ramirez-Valles J.
      • Kuhns L.M.
      • Manjarrez D.
      Tal Como Somos/Just as We Are: An educational film to reduce stigma toward gay and bisexual men, transgender individuals, and persons living with HIV/AIDS.
      ]
      2014USA44; 9th to 12th gradersNonexperimental, paired pre- and post-tests3, 4SO, GI
      Ryan et al. [
      • Ryan C.L.
      • Patraw J.M.
      • Bednar M.
      Discussing princess boys and pregnant men: Teaching about gender diversity and transgender experiences within an elementary school curriculum.
      ]
      2013USA1; 3rd grade class, 1 teacherQualitative; class discussions, informal interviews3, 5SO, GI
      Rice [
      • Rice P.S.
      Creating spaces for boys and girls to expand their definitions of masculinity and femininity through children's literature.
      ]
      2002USA24; 3rd gradersQualitative, class discussion4GI
      Dutro [
      • Dutro E.
      "But That's a Girls' Book!" Exploring gender boundaries in children's reading practices.
      ]
      2002USA24; 5th gradersQualitative, class discussion4GI
      Hermann-Wilmarth et al. [
      • Hermann-Wilmarth J.M.
      • Lannen R.
      • Ryan C.L.
      Critical literacy and transgender topics in an upper elementary classroom: A portrait of possibility.
      ]
      2017USA15; 4th to 5th gradersQualitative, class discussion4, 5SO, GI
      Knotts and Gregorio [
      • Knotts G.
      • Gregorio D.
      Confronting homophobia at school: High school students and the gay men's chorus of Los Angeles.
      ]
      2011USA101; 9th to 12th gradersNonexperimental, paired pre- and post-test. Class discussion5SO, GI
      Matthews et al. [
      • Matthews C.E.
      • Binkley W.
      • Crisp A.
      • Gregg K.
      Challenging gender bias in fifth grade.
      ]
      1998USA22; 5th gradersQualitative, class discussion5GI
      Smylie et al. [
      • Smylie L.
      • Maticka-Tyndale E.
      • Boyd D.
      Evaluation of a school-based sex education programme delivered to grade nine students in Canada.
      ]
      2008Canada240; 9th graders, 6 schoolsQuasi-experimental, pre- and post-test surveys5GI, CHR, AP
      Constantine et al. [
      • Constantine N.A.
      • Jerman P.
      • Berglas N.F.
      • et al.
      Short-term effects of a rights-based sexuality education curriculum for high-school students: A cluster-randomized trial.
      ]
      2015USA1,750; 9th graders, 10 high schoolsExperimental, pre- and post-test5, 13GI, CHR
      Rohrbach et al. [
      • Rohrbach L.A.
      • Berglas N.F.
      • Jerman P.
      • et al.
      A rights-based sexuality education cirriculum for adolescents: 1-year outcomes from a cluster-randomized trial.
      ]
      2015USA1,447; 9th graders, 10 high schoolsExperimental, pre, post, and 1-year follow-up5GI, CHR
      Barker et al. [
      • Barker G.
      • Ricardo C.
      • Nascimento M.
      • et al.
      Questioning gender norms with men to improve health outcomes: Evidence of impact.
      ]
      2010USAVariedSystematic literature review of 58 evaluation studies5GI
      Baiocchi et al. [
      • Baiocchi M.
      • Omondi B.
      • Langat N.
      • et al.
      A behavior-based intervention that prevents sexual assault: The results of a matched-pairs, cluster-randomized study in Nairobi, Kenya.
      ]
      2017Kenya6,356 girls aged 10–16 years, 30 primary schoolsExperimental, pre- and post-test5, 7GI, CHR
      Miller et al. [
      • Miller E.
      • Tancredi D.J.
      • McCauley H.L.
      • et al.
      Coaching boys into men: A cluster-randomized controlled trial of a dating violence prevention program.
      ]
      2012USA1,798; 9th to 12th grade boys, 16 high schoolsExperimental, pre and 3-month follow-up post-test5, 8GI, IV
      Haberland [
      • Haberland N.A.
      The case for addressing gender and power in sexuality and HIV education: A comprehensive review of evaluation studies.
      ]
      2015USAVariedSystematic literature review of 22 evaluation studies5IV, GI, SH
      Ting [
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ]
      2009USA and Canada13 middle and high schoolsMeta-analysis of knowledge and attitudes6, 7IV
      Foshee et al. [
      • Foshee V.A.
      • Bauman K.E.
      • Ennett S.T.
      • et al.
      Assessing the long-term effects of the safe dates program and a booster in preventing and reducing adolescent dating violence victimization and perpetration.
      ]
      2004USA460; 8th gradersExperimental, pre, post, and long-term follow-up7IV
      Foshee et al. [
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ]
      1998USA1886; 8th to 9th graders, 14 schoolsExperimental, pre-, post-test, 1-month follow-up6, 7, 13IV
      Crooks et al. [
      • Crooks C.V.
      • Scott K.L.
      • Broll R.
      • et al.
      Does an evidence-based healthy relationships program for 9th graders show similar effects for 7th and 8th graders? Results from 57 schools randomized to intervention.
      ]
      2015Canada1,012; 7th and 8th graders, 57 schoolsExperimental, pre-, post-test (1 month after program)6, 7IV
      Foshee et al. [
      • Foshee V.A.
      • Bauman K.E.
      • Greene W.F.
      • et al.
      The safe dates program: 1-year follow-up results.
      ]
      2000USA1886; 9th to 9th graders, 14 schoolsExperimental, pre, post, 1-year follow-up6, 7, 13IV, CHR
      Kervin and Obinna [
      • Kervin D.
      • Obinna J.
      Youth action strategies in the primary prevention of teen dating violence.
      ]
      2010USA49 HS studentsNonexperimental, pre and post-tests6, 7, 8IV, GI
      Wolfe et al. [
      • Wolfe D.A.
      • Crooks C.V.
      • Chiodo D.
      • et al.
      Observations of adolescent peer resistance skills following a classroom-based healthy relationship program: A post-intervention comparison.
      ]
      2012Canada196; 9th grade girlsExperimental, observational post-test substudy of students in a larger randomized trial10CHR
      Peskin et al. [
      • Peskin M.F.
      • Markham C.M.
      • Shegog R.
      • et al.
      Effects of the it’s your game… keep it real program on dating violence in ethnic-minority middle school youths: A group randomized trial.
      ]
      2014USA766; 7th to 9th graders, 10 middle schoolsExperimental, pre- and post-test7IV
      Rice et al. [
      • Rice T.M.
      • McGill J.
      • Adler-Baeder F.
      Relationship education for youth in high school: Preliminary evidence from a non-controlled study on dating behavior and parent-adolescent relationships.
      ]
      2017USA3,658; 9th to 12th graders, 30 high schoolsNonexperimental repeated measure surveys8, 9, 13CHR
      Taylor et al. [
      • Taylor B.
      • Stein N.
      • Burden F.
      The effects of gender violence/harassment prevention programming in middle schools: A randomized experimental evaluation.
      ]
      2010USA1,639; 6th to 7th graders, 3 middle schoolsExperimental, pre- and post-test with 5–6 month follow-up6, 7IV
      Pacifici et al. [
      • Pacifici C.
      • Stoolmiller M.
      • Nelson C.
      Evaluating a prevention program for teenagers on sexual coercion: A differential effectiveness approach.
      ]
      2001USA457; 9th to 12th graders, 2 high schoolsExperimental, pre and 10-day follow-up post-test7IV
      De La Rue et al. [
      • De La Rue L.
      • Polanin J.R.
      • Espelage D.L.
      • et al.
      School-based interventions to reduce dating and sexual violence: A systematic review.
      ]
      2014USAGrades 4–12Systematic literature review, 23 programs6, 7IV
      Smith and Welchans [
      • Smith P.
      • Welchans S.
      Peer education: Does focusing on male responsibility change sexual assault attitudes?.
      ]
      2000USA253; 10th to 12th gradersNonexperimental, unpaired pre- and post-test6IV
      Sosa-Rubi et al. [
      • Sosa-Rubi S.G.
      • Saavedra-Avendano B.
      • Piras C.
      • et al.
      True love: Effectiveness of a school-based program to reduce dating violence among adolescents in Mexico City.
      ]
      2017Mexico885; 9th to 12th graders, 2 high schoolsQuasi-experimental, matched pairs, pre- and post-tests5, 6IV
      Baker et al. [
      • Baker C.K.
      • Naai R.
      • Mitchell J.
      • Trecker C.
      Utilizing a train-the-trainer model for sexual violence prevention: Findings from a pilot study with high school students of Asian and Pacific Islander descent in Hawai‘i.
      ]
      2014USA136; 9th to 12th graders, 2 high schoolsQuasi-experimental, unpaired pre- and post-test with 1-month follow-up6, 8IV
      Macgowan [
      • Macgowan M.J.
      An evaluation of a dating violence prevention program for middle school students.
      ]
      1997USA440; 6th to 8th gradersExperimental, pre- and post-test6IV
      Meyer and Stein [
      • Meyer H.
      • Stein N.
      Relationship violence prevention education in schools: What's working, what's getting in the way, and what are some future directions.
      ]
      2004USAVaried, 6th to 12th gradersLiterature review of five programs6, 7IV
      Weisz and Black [
      • Weisz A.N.
      • Black B.M.
      Evaluating a sexual assault and dating violence prevention program for urban youth.
      ]
      2001USA66 African-American 7th gradersQuasi-experimental, unpaired pre- and post-test with 6-month follow-up6IV
      McLeod et al. [
      • McLeod D.A.
      • Jones R.
      • Cramer E.P.
      An evaluation of a school-based, peer-facilitated, healthy relationship program for at-risk adolescents.
      ]
      2015USA291; 9th graders, 3 high schoolsNonexperimental, unpaired pre- and post-test6, 9IV, CHR
      Adler-Baeder et al. [
      • Adler-Baeder F.
      • Kerpelman J.L.
      • Schramm D.G.
      • et al.
      The impact of relationship education on adolescents of diverse backgrounds.
      ]
      2007USA340; 9th to 12th graders, 9 high schoolsQuasi-experimental, paired pre- and post-test6, 7IV
      Jaycox et al. [
      • Jaycox L.H.
      • McCaffrey D.
      • Eiseman B.
      • et al.
      Impact of a school-based dating violence prevention program among Latino teens: Randomized controlled effectiveness trial.
      ]
      2006USA2,540; 9th graders, 10 high schoolsExperimental, pre- and post-test with 6-month follow-up6IV
      de Lijster et al. [
      • de Lijster G.P.A.
      • Felten H.
      • Kok G.
      • Kocken P.L.
      Effects of an interactive school-based program for preventing adolescent sexual harassment: A cluster-randomized controlled evaluation study.
      ]
      2016The Netherlands815; students, aged 12–16 years, 25 schoolsExperimental, pre- and post-test with 6-month follow-up6IV
      Roscoe et al. [
      • Roscoe B.
      • Strouse J.S.
      • Goodwin M.P.
      • et al.
      Sexual harassment: An educational program for middle school students.
      ]
      1994USA561; 7th and 8th gradersNonexperimental, pre and post-tests6IV
      Kernsmith and Hernandez-Jozefowicz [
      • Kernsmith P.D.
      • Hernandez-Jozefowicz D.M.
      A gender-sensitive peer education program for sexual assault prevention in the schools.
      ]
      2011USA343; 9th to 12th gradersNonexperimental, unpaired pre- and post-test with 3-month follow-up6IV
      Wolfe et al. [
      • Wolfe D.A.
      • Crooks C.
      • Jaffe P.
      • et al.
      A school-based program to prevent adolescent dating violence: A cluster randomized trial.
      ]
      2009Canada1,722; 9th graders, 20 high schoolsExperimental, pretest with 2.5 year follow-up7IV
      Mathews et al. [
      • Mathews C.
      • Eggers S.M.
      • Townsend L.
      • et al.
      Effects of PREPARE, a multi-component, school-based HIV and intimate partner violence (IPV) prevention programme on adolescent sexual risk behaviour and IPV: Cluster randomised controlled trial.
      ]
      2016South Africa3,451; 8th graders, 42 schoolsExperimental, pretest with 6-month and 12-month follow-up7IV
      Bates [
      • Bates R.C.
      An action research study: Using classroom guidance lessons to teach middle school students about sexual harassment.
      ]
      2006USA97; 7th gradersNonexperimental comparison of pre-during, and post discipline referrals7IV
      Kettry et al. [
      • Kettry H.H.
      • Marx R.
      • Tanner-Smith E.
      Effects of bystander programs on the prevention of sexual assault among adolescents and college students: A systematic review.
      ]
      2017USA27 studies, five were HSMeta-analysis of experimental and quasi-experimental studies, Grades 7–12 and college8IV
      Miller et al. [
      • Miller E.
      • Tancredi D.J.
      • McCauley H.L.
      • et al.
      One-year follow-up of a coach-delivered dating violence prevention program: A cluster randomized controlled trial.
      ]
      2013USA1,798; 9th to 12th grade boys, 16 high schoolsExperimental, pre and 3-month follow-up post-test5, 8GI, IV
      Pick et al. [
      • Pick S.
      • Givaudan M.
      • Sirkin J.
      • Ortega I.
      Communication as a protective factor: Evaluation of a life skills HIV/AIDS prevention program for mexican elementary-school students.
      ]
      2007Mexico1,581; 4th graders, 45 elementary schoolsExperimental pre- and post-test10, 13CHR
      Buote and Berglund [
      • Buote D.
      • Berglund P.
      Promoting social justice through building healthy relationships: Evaluation of SWOVA's "Respectful Relationships" program.
      ]
      2010Canada1,748; 7th to 10th graders, 31 schoolsNonexperimental, unpaired pre- and post-test10, 13CHR
      Lamb and Randazzo [
      • Lamb S.
      • Randazzo R.
      An examination of the effectiveness of a sexual ethics curriculum.
      ]
      2016USA79; 9th gradersNonexperimental, unpaired pre- and post-test10CHR
      Scull et al. [
      • Scull T.M.
      • Malik C.V.
      • Kupersmidt J.B.
      A media literacy education approach to teaching adolescents comprehensive sexual health education.
      ]
      2014USA56; 8th gradersNonexperimental, unpaired pre- and post-test10, 14CHR, SH
      Davis and Gidycz [
      • Davis M.K.
      • Gidycz C.A.
      Child sexual abuse prevention programs: A meta-analysis.
      ]
      2000USA27 studiesMeta-analysis of experimental and quasi-experimental studies, aged 3–13 years11,12CHR
      Kenny et al. [
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ]
      2008USA and CanadaAge 3–12 yearsSystematic literature review, 21 articles focused on five different programs11, 12, 13CHR
      Macintyre and Carr [
      • Macintyre D.
      • Carr A.
      Evaluation of the effectiveness of the stay safe primary prevention programme for child sexual abuse.
      ]
      1999Ireland727; 2nd and 5th graders across 5 schoolsExperimental, randomized by school, pre, post, follow-up11, 12, 13CHR, SH
      Walsh et al. [
      • Walsh K.
      • Zwi K.
      • Woolfenden S.
      • Shlonsky A.
      School-based education programs for the prevention of child sexual abuse: A cochrane systematic review and meta-analysis.
      ]
      2018USA, Canada, China, Germany, Spain, Taiwan, Turkey5,802 K-5 students across 24 studiesSystematic literature review10, 11CHR
      Topping and Barron [
      • Topping K.J.
      • Barron I.G.
      School-based child sexual abuse prevention programs: A review of effectiveness.
      ]
      2009USA, Canada, UK, Ireland, HollandVaried, K-6Systematic literature review of 22 studies11, 13CHR, SH
      Pulido et al. [
      • Pulido M.L.
      • Dauber S.
      • Tully B.A.
      • et al.
      Knowledge gains following a child sexual abuse prevention program among urban students: A cluster-randomized evaluation.
      ]
      2015USA492; 2nd and 3rd graders across 6 schoolsExperimental, pre- and post-test11CHR
      Baker et al. [
      • Baker C.K.
      • Gleason K.
      • Naai R.
      • et al.
      Increasing knowledge of sexual abuse: A study with elementary school children in Hawai'i.
      ]
      2012USA80; 3rd and 4th graders across 3 schoolsQuasi-experimental, pre- and post-test11CHR
      Hazzard et al. [
      • Hazzard A.
      • Webb C.
      • Kleemeier C.
      • et al.
      Child sexual abuse prevention: Evaluation and one-year follow-up.
      ]
      1991USA399; 3rd and 4th graders across 6 schoolsExperimental, randomized by school11CHR
      Brown [
      • Brown D.M.
      Evaluation of Safer, Smarter Kids: Child sexual abuse prevention curriculum for kindergartners.
      ]
      2016USA1,169; K students across 54 classrooms in four school districtsNonexperimental, unpaired and paired pre- and post-test11CHR
      Kenny et al. [
      • Kenny M.C.
      • Wurtele S.K.
      • Alonso L.
      Evaluation of a personal safety program with Latino preschoolers.
      ]
      2012USA123; PreK students aged 3–5 yearsQuasi-experimental unpaired pre, post, and 3-month follow-up11CHR
      Jin et al. [
      • Jin Y.
      • Chen J.
      • Jiang Y.
      • Yu B.
      Evaluation of a sexual abuse prevention education program for school-age children in China: A comparison of teachers and parents as instructors.
      ]
      2017China484; 1st to 5th graders in one primary schoolExperimental, pre, post and 12-week follow-up12CHR
      Kim and Kang [
      • Kim S.-J.
      • Kang K.-A.
      Effects of the child sexual abuse prevention education (C-SAPE) program on South Korean fifth-grade students' competence in terms of knowledge and self-protective behaviors.
      ]
      2017South Korea89; 5th graders across 3 schoolsQuasi-experimental with pre- and post-test12CHR
      Kater et al. [
      • Kater K.J.
      • Rohwer J.
      • Londre K.
      Evaluation of an upper elementary school program to prevent body image, eating, and weight concerns.
      ]
      2002USA415; 4th to 6th graders across 5 schoolsQuasi-experimental pre- and post-test13SH
      Halliwell et al. [
      • Halliwell E.
      • Yager Z.
      • Paraskeva N.
      • et al.
      Body image in primary schools: A pilot evaluation of a primary school intervention program designed by teachers to improve children's body satisfaction.
      ]
      2016UK144; students aged 9–10 years across 4 schoolsQuasi-experimental pre and post-test with 3-month follow-up13SH
      Dunstan et al. [
      • Dunstan C.J.
      • Paxton S.J.
      • McLean S.A.
      An evaluation of a body image intervention in adolescent girls delivered in single-sex versus co-educational classroom settings.
      ]
      2017Australia200; 7th grade girlsQuasi-experimental pre and post-test with 6-month follow-up13SH
      McCabe et al. [
      • McCabe M.P.
      • Ricciardelli L.A.
      • Karantzas G.
      Impact of a healthy body image program among adolescent boys on body image, negative affect, and body change strategies.
      ]
      2010Australia421; 7th to 9th grade boys aged 11–15 years across 5 schoolsQuasi-experimental pre and post-test with 3, 6, and 12-month follow-up13SH
      Berman and White [
      • Berman N.
      • White A.
      Refusing the Stereotype: Decoding negative gender imagery through a school-based digital media literacy program.
      ]
      2013Australia48; 8th graders across 3 schoolsNonexperimental, pre- and post-test13, 14CHR, SH
      CHR = consent and healthy relationships; AP = anatomy and physiology; PD = puberty and adolescent sexual development; GI = gender identity and expression; SO = sexual orientation and identity; SH = sexual health; IV = interpersonal violence; YRBS = Youth Risk Behavior Surveillance.
      a Outcome Subtopics:Appreciation of sexual diversity: 1 = lower homophobia; 2 = reduced homophobic bullying; 3 = expanded understanding of gender/gender norms; 4 = recognition of gender equity, rights, social justice.Dating and intimate partner violence: 5 = improved knowledge and attitudes about, and reporting of, sexual and intimate partner violence; 6 = decreased sexual and intimate partner violence perpetration and victimization; 7 = increased bystander intentions and behaviors.Healthy relationships: 8 = increased relationship knowledge, attitudes, and skills; 9 = improved communication skills and intentions.Child sex abuse: 10 = improved knowledge, attitudes, skills, and social–emotional outcomes related to personal safety and touch; 11 = improved disclosure skills and behaviors.Additional outcomes: 12 = social–emotional learning; 13 = media literacy.
      A notable update in the NSES Second Edition is a prominent focus on social justice and equity, as well as intersectionality. Some of the findings of this SLR reflect this broader conceptual focus and are reported as such here.

      Appreciation of sexual diversity

      Studies discussed in this section report on outcomes that together represent appreciation of sexual diversity. Classroom approaches ranged from preschool through grade 12, were found throughout the curriculum (not just in health or sex education), and included, in many cases, the use of literature to address gender and sexual orientation issues. Research on LGBTQ–inclusive curricula across topics and grade levels are reviewed, as well as approaches aimed specifically at reducing homophobia, homophobic bullying and harassment, and other outcomes related to appreciation of sexual diversity.

      Lower homophobia

      Curricula designed specifically to reduce homophobia have been found to be successful across grade levels using a variety of approaches both formally within sexuality education and throughout other areas of the curriculum [
      • Schall J.
      • Kauffmann G.
      Exploring literature with gay and lesbian characters in the elementary school.
      ,
      • Eick U.
      • Rubinstein T.
      • Hertz S.
      • Slater A.
      Changing attitudes of high school students in Israel toward homosexuality.
      ,
      • Richard G.
      • Vallerand O.
      • Petit M.P.
      • Charbonneau A.
      Discussing sexual orientation and gender in classrooms: A testimonial-based approach to fighting homophobia in schools.
      ,
      • Athanases S.Z.
      A gay-themed lesson in an ethnic literature curriculum: Tenth graders' responses to `Dear Anita'.
      ,
      • Van de Ven P.
      Effects on high school students of a teaching module for reducing homophobia.
      ,
      • Helmer K.
      "Everyone needs a class like this": High school students' perspectives on a gay and lesbian literature course.
      ,
      • Helmer K.
      Gay and lesbian literature disrupting the heteronormative space of the high school English classroom.
      ,
      • Alan H.
      • Miriam I.
      LGBTQ youth in american schools: Moving to the middle.
      ,
      • Bentley D.F.
      • Souto-Manning M.
      Toward inclusive understandings of marriage in an early childhood classroom: Negotiating (un)readiness, community, and vulnerability through a critical reading of "King and King".
      ,
      • Lucassen M.F.
      • Burford J.
      Educating for diversity: An evaluation of a sexuality diversity workshop to address secondary school bullying.
      ,
      • Brown L.K.
      • Barone V.J.
      • Fritz G.K.
      • et al.
      AIDS education: The Rhode Island experience.
      ]. Programs that brought in guest speakers from the LGB community to share personal stories resulted in reduced homophobic attitudes [
      • Eick U.
      • Rubinstein T.
      • Hertz S.
      • Slater A.
      Changing attitudes of high school students in Israel toward homosexuality.
      ,
      • Richard G.
      • Vallerand O.
      • Petit M.P.
      • Charbonneau A.
      Discussing sexual orientation and gender in classrooms: A testimonial-based approach to fighting homophobia in schools.
      ]. A Quebec study using immediate post-tests and 3-month follow-ups, as well as participant interviews and focus groups, reported on 227 high school (HS) students who participated in a program in which a gay man and a lesbian spoke in their classrooms. Students exhibited increased normalization of lesbian and gay people, a reduction in stereotyping about gender expression and norms for lesbian and gay women and men, empathy for those who come out, an appreciation for the positive aspects of being lesbian and gay, a recognition that sexual orientation does not have to correlate with sexual behavior, and lower use of homophobic slurs [
      • Richard G.
      • Vallerand O.
      • Petit M.P.
      • Charbonneau A.
      Discussing sexual orientation and gender in classrooms: A testimonial-based approach to fighting homophobia in schools.
      ]. Strategies that use literature featuring gay and lesbian characters have also resulted in lowered homophobia and homophobic behaviors both at the elementary school level [
      • Schall J.
      • Kauffmann G.
      Exploring literature with gay and lesbian characters in the elementary school.
      ] and in high school [
      • Athanases S.Z.
      A gay-themed lesson in an ethnic literature curriculum: Tenth graders' responses to `Dear Anita'.
      ,
      • Helmer K.
      "Everyone needs a class like this": High school students' perspectives on a gay and lesbian literature course.
      ,
      • Helmer K.
      Gay and lesbian literature disrupting the heteronormative space of the high school English classroom.
      ].

      Reduced homophobic bullying

      In addition to reduced homophobic attitudes, research demonstrates that curricula that are inclusive of all sexual orientations, gender identities, and expressions, across areas of study, and most strongly within CSE, reduce homophobic bullying and harassment, and increase safety for LGBTQ students [
      • Richard G.
      • Vallerand O.
      • Petit M.P.
      • Charbonneau A.
      Discussing sexual orientation and gender in classrooms: A testimonial-based approach to fighting homophobia in schools.
      ,
      • Snapp S.D.
      • McGuire J.K.
      • Sinclair K.O.
      • et al.
      LGBTQ-inclusive curricula: Why supportive curricula matter.
      ,
      • Baams L.
      • Dubas J.
      • van Aken M.
      Comprehensive sexuality education as a longitudinal predictor of LGBTQ name-calling and perceived willingness to intervene in school.
      ].
      A 2015 survey of 1,232 gay and straight middle and high school students from 154 schools in California found that inclusive curricula were associated with higher reports of safety at both the individual and school levels and lower levels of bullying at the school level. LGBTQ-supportive curricula were also related to students feeling safer at school and more aware of bullying at both the school and individual levels. Although these outcomes resulted from inclusiveness throughout the curriculum, the study found that having sex education and health classes that were LGBTQ inclusive had the greatest impact on school climate [
      • Snapp S.D.
      • McGuire J.K.
      • Sinclair K.O.
      • et al.
      LGBTQ-inclusive curricula: Why supportive curricula matter.
      ].
      A rigorous, three-wave longitudinal study examined an LGBTQ-inclusive curriculum in six Dutch high schools provided to 601 tenth- to twelfth-grade students. Researchers found that, along with covering a variety of topics, inclusion of sexual orientation and gender identity that was extensive in both content and frequency predicted decreased name-calling and, among girls, increased willingness to intervene when witnessing name-calling by others, leading to an improved school climate [
      • Baams L.
      • Dubas J.
      • van Aken M.
      Comprehensive sexuality education as a longitudinal predictor of LGBTQ name-calling and perceived willingness to intervene in school.
      ]. Other methodologically strong studies have found that LGBTQ-inclusive sex education is related to lower reports of adverse mental health (suicidal thoughts and suicide plans) among all youth and of experiences of bullying among sexual minority youth [
      • Proulx C.N.
      • Coulter R.W.
      • Egan J.E.
      • et al.
      Associations of lesbian, gay, bisexual, transgender, and questioning-inclusive sex education with mental health outcomes and school-based victimization in U.S. high school students.
      ]. As well, they are related to better health outcomes among gay, lesbian, and bisexual students, including fewer sex partners, less use of drugs or alcohol before sex, less pregnancy, and better school attendance [
      • Blake S.M.
      • Ledsky R.
      • Lehman T.
      • et al.
      Preventing sexual risk behaviors among gay, lesbian, and bisexual adolescents: The benefits of gay-sensitive HIV instruction in schools.
      ].

      Expanded understanding of gender/gender norms

      Although research suggests that narrow views of gender and the reinforcement of gender stereotypes in young children can lead to gender-based harassment [
      • Hill C.A.
      • Kearl H.
      Crossing the line: Sexual harassment at school.
      ], little evaluation research has looked at efforts to counteract these views. A few smaller studies, including qualitative/ethnographic research and studies looking at short-term or single-dose programs, taken together, suggest that focused efforts to increase acceptance of transgender and gender-nonconforming people can be effective [
      • Richard G.
      • Vallerand O.
      • Petit M.P.
      • Charbonneau A.
      Discussing sexual orientation and gender in classrooms: A testimonial-based approach to fighting homophobia in schools.
      ,
      • Ramirez-Valles J.
      • Kuhns L.M.
      • Manjarrez D.
      Tal Como Somos/Just as We Are: An educational film to reduce stigma toward gay and bisexual men, transgender individuals, and persons living with HIV/AIDS.
      ,
      • Ryan C.L.
      • Patraw J.M.
      • Bednar M.
      Discussing princess boys and pregnant men: Teaching about gender diversity and transgender experiences within an elementary school curriculum.
      ]. Qualitative studies of efforts to expand understanding of gender and gender norms, all at the elementary school level (third to fifth grades), suggest that making children's literature that challenges gender stereotypes available and accessible to students may not be enough. Using that literature to engage students in discussions, relating gender-based bullying and harassment to harassment and oppression of other marginalized populations, and using a critical literacy approach [
      • Shor I.
      What is critical literacy?.
      ] engaged students in different ways of thinking about and expressing the messages from these books and other media. They also helped young children to expand their views of gender, gender expression, and gender norms and created an environment that allowed students to challenge and to cross their own stereotypical gender boundaries safely [
      • Ryan C.L.
      • Patraw J.M.
      • Bednar M.
      Discussing princess boys and pregnant men: Teaching about gender diversity and transgender experiences within an elementary school curriculum.
      ,
      • Rice P.S.
      Creating spaces for boys and girls to expand their definitions of masculinity and femininity through children's literature.
      ,
      • Dutro E.
      "But That's a Girls' Book!" Exploring gender boundaries in children's reading practices.
      ,
      • Hermann-Wilmarth J.M.
      • Lannen R.
      • Ryan C.L.
      Critical literacy and transgender topics in an upper elementary classroom: A portrait of possibility.
      ].
      In one participant-observation study of a literature-based gender norms curriculum with suburban, Midwest African-American fifth graders [
      • Dutro E.
      "But That's a Girls' Book!" Exploring gender boundaries in children's reading practices.
      ], the author reported that “over time…both girls and boys felt safe in discussing and challenging one another's assumptions about gender's role in their reading choices” (p. 384) and concluded, “Children need safe spaces in which to experience, play with, and begin to challenge the naturalized assumptions about gender.” (p. 384). The studies noted here, as well as one of a preschool class [
      • Bentley D.F.
      • Souto-Manning M.
      Toward inclusive understandings of marriage in an early childhood classroom: Negotiating (un)readiness, community, and vulnerability through a critical reading of "King and King".
      ], highlight that young children are, in fact, quite capable of understanding and discussing issues related to gender diversity, including gender expectations, gender nonconformity, and gender-based oppression. They also underscore that the development of such understanding requires instructional scaffolding over a period, and not just one session.

      Recognition of gender equity, rights, and social justice

      The use of social justice and rights-based frameworks in designing and teaching topics related to sexuality and sexual health has increased over the past several years and has been advocated by leading sexual health organizations [
      Future of Sex Education Initiative
      National sex education standards: Core content and skills, K-12.
      ,
      Fund UNP
      International technical guidance on sexuality education: An evidence-informed approach.
      ]. A social justice lens uses the concepts of human rights and equality through which to challenge power, privilege, and structural and systemic discrimination of marginalized communities. There is evidence to suggest that this approach is well-founded and can be applied across the curriculum and at all grade levels [
      • Athanases S.Z.
      A gay-themed lesson in an ethnic literature curriculum: Tenth graders' responses to `Dear Anita'.
      ,
      • Helmer K.
      "Everyone needs a class like this": High school students' perspectives on a gay and lesbian literature course.
      ,
      • Hermann-Wilmarth J.M.
      • Lannen R.
      • Ryan C.L.
      Critical literacy and transgender topics in an upper elementary classroom: A portrait of possibility.
      ,
      • Knotts G.
      • Gregorio D.
      Confronting homophobia at school: High school students and the gay men's chorus of Los Angeles.
      ,
      • Rands K.
      Supporting transgender and gender-nonconforming youth through teaching mathematics for social justice.
      ]. A number of studies report outcomes related to increased knowledge, awareness and appreciation of gender equity and sexual rights, and awareness of discrimination and oppression based on gender and sexual orientation [
      • Athanases S.Z.
      A gay-themed lesson in an ethnic literature curriculum: Tenth graders' responses to `Dear Anita'.
      ,
      • Helmer K.
      "Everyone needs a class like this": High school students' perspectives on a gay and lesbian literature course.
      ,
      • Helmer K.
      Gay and lesbian literature disrupting the heteronormative space of the high school English classroom.
      ,
      • Bentley D.F.
      • Souto-Manning M.
      Toward inclusive understandings of marriage in an early childhood classroom: Negotiating (un)readiness, community, and vulnerability through a critical reading of "King and King".
      ,
      • Ryan C.L.
      • Patraw J.M.
      • Bednar M.
      Discussing princess boys and pregnant men: Teaching about gender diversity and transgender experiences within an elementary school curriculum.
      ,
      • Hermann-Wilmarth J.M.
      • Lannen R.
      • Ryan C.L.
      Critical literacy and transgender topics in an upper elementary classroom: A portrait of possibility.
      ,
      • Knotts G.
      • Gregorio D.
      Confronting homophobia at school: High school students and the gay men's chorus of Los Angeles.
      ,
      • Matthews C.E.
      • Binkley W.
      • Crisp A.
      • Gregg K.
      Challenging gender bias in fifth grade.
      ,
      • Smylie L.
      • Maticka-Tyndale E.
      • Boyd D.
      Evaluation of a school-based sex education programme delivered to grade nine students in Canada.
      ,
      • Constantine N.A.
      • Jerman P.
      • Berglas N.F.
      • et al.
      Short-term effects of a rights-based sexuality education curriculum for high-school students: A cluster-randomized trial.
      ].
      The programs on which the research is based span preschool through high school and range from a one-shot music-based program focused on attitudinal change related to racism, classism, homophobia, and misogyny [
      • Knotts G.
      • Gregorio D.
      Confronting homophobia at school: High school students and the gay men's chorus of Los Angeles.
      ] to a year-long, multimedia program on gender equity for fifth graders [
      • Matthews C.E.
      • Binkley W.
      • Crisp A.
      • Gregg K.
      Challenging gender bias in fifth grade.
      ], both of which reported increased understanding and awareness of these rights-based issues. One strong study using a clustered randomized trial to evaluate a 12-session, rights-based approach to sexuality education among predominantly Hispanic and African-American HS populations in Los Angeles found that, compared with students who received more traditional sex education, students who received the rights-based curriculum demonstrated more positive attitudes about sexual relationship rights [
      • Constantine N.A.
      • Jerman P.
      • Berglas N.F.
      • et al.
      Short-term effects of a rights-based sexuality education curriculum for high-school students: A cluster-randomized trial.
      ,
      • Rohrbach L.A.
      • Berglas N.F.
      • Jerman P.
      • et al.
      A rights-based sexuality education cirriculum for adolescents: 1-year outcomes from a cluster-randomized trial.
      ].
      As well, the research supports approaches that use literature to study LGBTQ rights and break down stereotyped beliefs using a social justice lens [
      • Schall J.
      • Kauffmann G.
      Exploring literature with gay and lesbian characters in the elementary school.
      ,
      • Athanases S.Z.
      A gay-themed lesson in an ethnic literature curriculum: Tenth graders' responses to `Dear Anita'.
      ,
      • Helmer K.
      "Everyone needs a class like this": High school students' perspectives on a gay and lesbian literature course.
      ,
      • Helmer K.
      Gay and lesbian literature disrupting the heteronormative space of the high school English classroom.
      ,
      • Bentley D.F.
      • Souto-Manning M.
      Toward inclusive understandings of marriage in an early childhood classroom: Negotiating (un)readiness, community, and vulnerability through a critical reading of "King and King".
      ,
      • Ryan C.L.
      • Patraw J.M.
      • Bednar M.
      Discussing princess boys and pregnant men: Teaching about gender diversity and transgender experiences within an elementary school curriculum.
      ]. One such ethnographic study of a 10th grade literature class on oppression and diversity used field notes; audiotapes and videotapes; student surveys; writing samples; interviews with teachers, students, parents, and school personnel; and a retrospective group discussion with students 2 years post-intervention [
      • Athanases S.Z.
      A gay-themed lesson in an ethnic literature curriculum: Tenth graders' responses to `Dear Anita'.
      ]. Respondents reported having myths of homosexuality dispelled, emerging empathy for gays and lesbians, and a belief in rights of gay and lesbian people to be who they are. The authors noted that establishing a safe climate in which to discuss sensitive and controversial issues was essential to the positive outcomes. Despite being an older (1996) study, it nonetheless supports the use of targeted strategies to increase acceptance and understanding of the LGBTQ community. Another study examined a high school literature class that used an “anti-oppression curriculum.” Using qualitative analysis software to analyze teacher and student interviews and questionnaires, the study reported that students moved from discomfort to confidence in discussing LGBTQ issues, gained a fuller understanding of the complexities of sexuality, and became more supportive allies and advocates of the LGBTQ community [
      • Helmer K.
      "Everyone needs a class like this": High school students' perspectives on a gay and lesbian literature course.
      ].
      Two smaller studies are worth noting for their support of teaching about sexual rights in the context of social justice to younger children. In one, fourth- and fifth-grade students exposed to LGBTQ literature, history, and current events were successful in discussing and understanding issues of social justice and equity for LGBTQ people. They had the capacity to understand LGBTQ discrimination and lack of power and how they are related to oppression based on race, religion, culture, and other identities [
      • Hermann-Wilmarth J.M.
      • Lannen R.
      • Ryan C.L.
      Critical literacy and transgender topics in an upper elementary classroom: A portrait of possibility.
      ]. In a qualitative study of a preschool class that used literature to discuss marriage equality and LGBT rights, 4-year-olds expressed an inclusive understanding of marriage and a social justice stance on LGBTQ rights [
      • Bentley D.F.
      • Souto-Manning M.
      Toward inclusive understandings of marriage in an early childhood classroom: Negotiating (un)readiness, community, and vulnerability through a critical reading of "King and King".
      ].
      Finally, there is support for programs that use a gender-transformative approach to promote more equitable relationships among genders. Such programs make discussions of gender in the context of power and the promotion of gender equality and women's empowerment, central to an intervention [
      • Barker G.
      • Ricardo C.
      • Nascimento M.
      • et al.
      Questioning gender norms with men to improve health outcomes: Evidence of impact.
      ]. Studies of this approach showed reduced adherence to gender norms and gender-related power structures [
      • Constantine N.A.
      • Jerman P.
      • Berglas N.F.
      • et al.
      Short-term effects of a rights-based sexuality education curriculum for high-school students: A cluster-randomized trial.
      ,
      • Baiocchi M.
      • Omondi B.
      • Langat N.
      • et al.
      A behavior-based intervention that prevents sexual assault: The results of a matched-pairs, cluster-randomized study in Nairobi, Kenya.
      ]. Such programs also had notable positive impacts on sexual health, personal safety, and bystander intentions [
      • Constantine N.A.
      • Jerman P.
      • Berglas N.F.
      • et al.
      Short-term effects of a rights-based sexuality education curriculum for high-school students: A cluster-randomized trial.
      ,
      • Rohrbach L.A.
      • Berglas N.F.
      • Jerman P.
      • et al.
      A rights-based sexuality education cirriculum for adolescents: 1-year outcomes from a cluster-randomized trial.
      ,
      • Miller E.
      • Tancredi D.J.
      • McCauley H.L.
      • et al.
      Coaching boys into men: A cluster-randomized controlled trial of a dating violence prevention program.
      ,
      • Haberland N.A.
      The case for addressing gender and power in sexuality and HIV education: A comprehensive review of evaluation studies.
      ]. Finally, although the current literature review is not focused on disease and pregnancy prevention programs, it is important to note that a focus on gender and power has the potential to influence a broad array of important sexual health outcomes. A meta-analysis that reviewed 22 sexuality and HIV curricula, across multiple age groups, found that programs addressing gender and power in relationships were five times more likely to be effective in reducing STI and pregnancy rates than those that did not address these topics. Specifically, 80% of such curricula versus 12% of curricula that did not address these topics were associated with lower STI and pregnancy rates [
      • Haberland N.A.
      The case for addressing gender and power in sexuality and HIV education: A comprehensive review of evaluation studies.
      ].

      Dating and intimate partner violence prevention

      Strong evaluations demonstrate a range of positive outcomes for programs that focus on prevention of dating violence (DV) and intimate partner violence (IPV) among both middle school and high school youth. The terms DV and IPV are used interchangeably in some studies, while others, particularly those that are earlier, tend to use only the term DV.) School-based efforts have the potential to play an important role in reducing DV and, in many cases, have shown positive long-term outcomes [
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ,
      • Foshee V.A.
      • Bauman K.E.
      • Ennett S.T.
      • et al.
      Assessing the long-term effects of the safe dates program and a booster in preventing and reducing adolescent dating violence victimization and perpetration.
      ]. Outside of pregnancy and disease prevention, this has been the most extensively evaluated aspect of school-based sex education efforts. There is strong evidence that programs can increase knowledge, change attitudes, and improve skills to reduce DV and IPV and can actually reduce the incidence of both DV and IPV.
      The most promising approaches to addressing DV and IPV for school-aged youth have focused on social justice [
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ,
      • Crooks C.V.
      • Scott K.L.
      • Broll R.
      • et al.
      Does an evidence-based healthy relationships program for 9th graders show similar effects for 7th and 8th graders? Results from 57 schools randomized to intervention.
      ], shifting norms around DV [
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ,
      • Foshee V.A.
      • Bauman K.E.
      • Greene W.F.
      • et al.
      The safe dates program: 1-year follow-up results.
      ] and/or gender roles [
      • Kervin D.
      • Obinna J.
      Youth action strategies in the primary prevention of teen dating violence.
      ], and conflict management skills [
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ,
      • Crooks C.V.
      • Scott K.L.
      • Broll R.
      • et al.
      Does an evidence-based healthy relationships program for 9th graders show similar effects for 7th and 8th graders? Results from 57 schools randomized to intervention.
      ]. Programs in this category have used a variety of educational methods, including instruction that supports social–emotional learning (SEL) [
      • Crooks C.V.
      • Scott K.L.
      • Broll R.
      • et al.
      Does an evidence-based healthy relationships program for 9th graders show similar effects for 7th and 8th graders? Results from 57 schools randomized to intervention.
      ,
      • Wolfe D.A.
      • Crooks C.V.
      • Chiodo D.
      • et al.
      Observations of adolescent peer resistance skills following a classroom-based healthy relationship program: A post-intervention comparison.
      ], role-plays [
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ], multiple sessions and/or grade levels [
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ,
      • Wolfe D.A.
      • Crooks C.V.
      • Chiodo D.
      • et al.
      Observations of adolescent peer resistance skills following a classroom-based healthy relationship program: A post-intervention comparison.
      ,
      • Peskin M.F.
      • Markham C.M.
      • Shegog R.
      • et al.
      Effects of the it’s your game… keep it real program on dating violence in ethnic-minority middle school youths: A group randomized trial.
      ,
      • Rice T.M.
      • McGill J.
      • Adler-Baeder F.
      Relationship education for youth in high school: Preliminary evidence from a non-controlled study on dating behavior and parent-adolescent relationships.
      ], theater [
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ], peer education [
      • Crooks C.V.
      • Scott K.L.
      • Broll R.
      • et al.
      Does an evidence-based healthy relationships program for 9th graders show similar effects for 7th and 8th graders? Results from 57 schools randomized to intervention.
      ], and enhanced building-level interventions [
      • Taylor B.
      • Stein N.
      • Burden F.
      The effects of gender violence/harassment prevention programming in middle schools: A randomized experimental evaluation.
      ], and have focused on sexual coercion, such as pressure, date rape, and exploitation [
      • Pacifici C.
      • Stoolmiller M.
      • Nelson C.
      Evaluating a prevention program for teenagers on sexual coercion: A differential effectiveness approach.
      ,
      • Beyer C.E.
      • Ogletree R.J.
      Sexual coercion content in 21 sexuality education curricula.
      ].

      Improved knowledge and attitudes about, and reporting of, DV and IPV

      There is extensive evidence that school-based programs have resulted in improved knowledge and attitudes related to DV and IPV, including reduction in rape myths, victim blaming, and sexist attitudes [
      • Taylor B.
      • Stein N.
      • Burden F.
      The effects of gender violence/harassment prevention programming in middle schools: A randomized experimental evaluation.
      ,
      • De La Rue L.
      • Polanin J.R.
      • Espelage D.L.
      • et al.
      School-based interventions to reduce dating and sexual violence: A systematic review.
      ,
      • Smith P.
      • Welchans S.
      Peer education: Does focusing on male responsibility change sexual assault attitudes?.
      ,
      • Sosa-Rubi S.G.
      • Saavedra-Avendano B.
      • Piras C.
      • et al.
      True love: Effectiveness of a school-based program to reduce dating violence among adolescents in Mexico City.
      ,
      • Baker C.K.
      • Naai R.
      • Mitchell J.
      • Trecker C.
      Utilizing a train-the-trainer model for sexual violence prevention: Findings from a pilot study with high school students of Asian and Pacific Islander descent in Hawai‘i.
      ,
      • Macgowan M.J.
      An evaluation of a dating violence prevention program for middle school students.
      ], and increased knowledge and attitudes about IPV [
      • Crooks C.V.
      • Scott K.L.
      • Broll R.
      • et al.
      Does an evidence-based healthy relationships program for 9th graders show similar effects for 7th and 8th graders? Results from 57 schools randomized to intervention.
      ,
      • Foshee V.A.
      • Bauman K.E.
      • Greene W.F.
      • et al.
      The safe dates program: 1-year follow-up results.
      ,
      • Kervin D.
      • Obinna J.
      Youth action strategies in the primary prevention of teen dating violence.
      ,
      • De La Rue L.
      • Polanin J.R.
      • Espelage D.L.
      • et al.
      School-based interventions to reduce dating and sexual violence: A systematic review.
      ,
      • Macgowan M.J.
      An evaluation of a dating violence prevention program for middle school students.
      ,
      • Meyer H.
      • Stein N.
      Relationship violence prevention education in schools: What's working, what's getting in the way, and what are some future directions.
      ,
      • Weisz A.N.
      • Black B.M.
      Evaluating a sexual assault and dating violence prevention program for urban youth.
      ,
      • McLeod D.A.
      • Jones R.
      • Cramer E.P.
      An evaluation of a school-based, peer-facilitated, healthy relationship program for at-risk adolescents.
      ,
      • Adler-Baeder F.
      • Kerpelman J.L.
      • Schramm D.G.
      • et al.
      The impact of relationship education on adolescents of diverse backgrounds.
      ]. Strong evaluations have demonstrated improved communication skills and handling feelings of anger [
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ,
      • Foshee V.A.
      • Bauman K.E.
      • Greene W.F.
      • et al.
      The safe dates program: 1-year follow-up results.
      ], increased awareness of laws and victim services [
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ,
      • Foshee V.A.
      • Bauman K.E.
      • Greene W.F.
      • et al.
      The safe dates program: 1-year follow-up results.
      ,
      • Jaycox L.H.
      • McCaffrey D.
      • Eiseman B.
      • et al.
      Impact of a school-based dating violence prevention program among Latino teens: Randomized controlled effectiveness trial.
      ], and reduced acceptance of sexual coercion [
      • Pacifici C.
      • Stoolmiller M.
      • Nelson C.
      Evaluating a prevention program for teenagers on sexual coercion: A differential effectiveness approach.
      ]. Programs have resulted in increased intentions to reduce coercion [
      • de Lijster G.P.A.
      • Felten H.
      • Kok G.
      • Kocken P.L.
      Effects of an interactive school-based program for preventing adolescent sexual harassment: A cluster-randomized controlled evaluation study.
      ] and have demonstrated increased self-efficacy [
      • de Lijster G.P.A.
      • Felten H.
      • Kok G.
      • Kocken P.L.
      Effects of an interactive school-based program for preventing adolescent sexual harassment: A cluster-randomized controlled evaluation study.
      ] and adherence to social norms [
      • Roscoe B.
      • Strouse J.S.
      • Goodwin M.P.
      • et al.
      Sexual harassment: An educational program for middle school students.
      ] to reject sexual harassment. In one study, significant change in HS students' attitudes about DV at post-test and follow-up was greater for students who had reported higher school connectedness at pretest [
      • Kernsmith P.D.
      • Hernandez-Jozefowicz D.M.
      A gender-sensitive peer education program for sexual assault prevention in the schools.
      ]. This finding suggests that efforts to help connect youth to school more generally may have the potential to influence longer term outcomes beyond school performance.

      Decreased DV and IPV perpetration and victimization

      Several large, rigorous studies are notable for strong behavioral outcomes in the area of DV and IPV prevention. These include a randomized evaluation of The Fourth R [
      • Crooks C.V.
      • Scott K.L.
      • Broll R.
      • et al.
      Does an evidence-based healthy relationships program for 9th graders show similar effects for 7th and 8th graders? Results from 57 schools randomized to intervention.
      ], a meta-analysis of 23 DV and IPV program evaluations in Grades 4 to 12 [
      • De La Rue L.
      • Polanin J.R.
      • Espelage D.L.
      • et al.
      School-based interventions to reduce dating and sexual violence: A systematic review.
      ], a review of multiple studies on five different 6th- to 12th-grade programs [
      • Meyer H.
      • Stein N.
      Relationship violence prevention education in schools: What's working, what's getting in the way, and what are some future directions.
      ] and a randomized, longitudinal study of Safe Dates [
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ,
      • Foshee V.A.
      • Bauman K.E.
      • Greene W.F.
      • et al.
      The safe dates program: 1-year follow-up results.
      ]. These and other school-based programs have led to reductions in DV and IPV perpetration [
      • Foshee V.A.
      • Bauman K.E.
      • Ennett S.T.
      • et al.
      Assessing the long-term effects of the safe dates program and a booster in preventing and reducing adolescent dating violence victimization and perpetration.
      ,
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ,
      • Kervin D.
      • Obinna J.
      Youth action strategies in the primary prevention of teen dating violence.
      ,
      • Meyer H.
      • Stein N.
      Relationship violence prevention education in schools: What's working, what's getting in the way, and what are some future directions.
      ,
      • Wolfe D.A.
      • Crooks C.
      • Jaffe P.
      • et al.
      A school-based program to prevent adolescent dating violence: A cluster randomized trial.
      ], victimization [
      • Baiocchi M.
      • Omondi B.
      • Langat N.
      • et al.
      A behavior-based intervention that prevents sexual assault: The results of a matched-pairs, cluster-randomized study in Nairobi, Kenya.
      ,
      • Foshee V.A.
      • Bauman K.E.
      • Ennett S.T.
      • et al.
      Assessing the long-term effects of the safe dates program and a booster in preventing and reducing adolescent dating violence victimization and perpetration.
      ,
      • Peskin M.F.
      • Markham C.M.
      • Shegog R.
      • et al.
      Effects of the it’s your game… keep it real program on dating violence in ethnic-minority middle school youths: A group randomized trial.
      ,
      • Taylor B.
      • Stein N.
      • Burden F.
      The effects of gender violence/harassment prevention programming in middle schools: A randomized experimental evaluation.
      ,
      • De La Rue L.
      • Polanin J.R.
      • Espelage D.L.
      • et al.
      School-based interventions to reduce dating and sexual violence: A systematic review.
      ,
      • Wolfe D.A.
      • Crooks C.
      • Jaffe P.
      • et al.
      A school-based program to prevent adolescent dating violence: A cluster randomized trial.
      ,
      • Mathews C.
      • Eggers S.M.
      • Townsend L.
      • et al.
      Effects of PREPARE, a multi-component, school-based HIV and intimate partner violence (IPV) prevention programme on adolescent sexual risk behaviour and IPV: Cluster randomised controlled trial.
      ], emotional violence perpetration [
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ,
      • Sosa-Rubi S.G.
      • Saavedra-Avendano B.
      • Piras C.
      • et al.
      True love: Effectiveness of a school-based program to reduce dating violence among adolescents in Mexico City.
      ], verbal aggression [
      • Adler-Baeder F.
      • Kerpelman J.L.
      • Schramm D.G.
      • et al.
      The impact of relationship education on adolescents of diverse backgrounds.
      ], and referrals for harassment [
      • Bates R.C.
      An action research study: Using classroom guidance lessons to teach middle school students about sexual harassment.
      ]. Some outcomes were found to have persisted for up to 4 years post-intervention [
      • Foshee V.A.
      • Bauman K.E.
      • Ennett S.T.
      • et al.
      Assessing the long-term effects of the safe dates program and a booster in preventing and reducing adolescent dating violence victimization and perpetration.
      ,
      • Peskin M.F.
      • Markham C.M.
      • Shegog R.
      • et al.
      Effects of the it’s your game… keep it real program on dating violence in ethnic-minority middle school youths: A group randomized trial.
      ,
      • Wolfe D.A.
      • Crooks C.
      • Jaffe P.
      • et al.
      A school-based program to prevent adolescent dating violence: A cluster randomized trial.
      ].
      Notably, several programs that took place in the eighth grade or earlier showed important long-term outcomes. The Fourth R: Skills for Youth Relationships, initially developed for ninth graders, stands out for its sequential version in Grades 7 and 8, demonstrating decreases in both physical and emotional DV among boys at ninth-grade follow-up [
      • Wolfe D.A.
      • Crooks C.
      • Jaffe P.
      • et al.
      A school-based program to prevent adolescent dating violence: A cluster randomized trial.
      ]. Safe Dates, in the eighth grade, with evaluation differentiating a range of violence-related outcomes, demonstrated reduction of sexual violence perpetration at immediate post-test [
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ], as well as reduced perpetration and victimization of physical violence at the 4-year follow-up. Compared with controls, treatment schools reported 25% less psychological abuse perpetration, 60% less sexual violence perpetration, and 60% less physical violence perpetration with a current dating partner [
      • Foshee V.A.
      • Bauman K.E.
      • Ennett S.T.
      • et al.
      Assessing the long-term effects of the safe dates program and a booster in preventing and reducing adolescent dating violence victimization and perpetration.
      ].

      Increased bystander intentions and behaviors

      Research on school-based bystander intervention programs has demonstrated increases in reported positive bystander behaviors [
      • Miller E.
      • Tancredi D.J.
      • McCauley H.L.
      • et al.
      Coaching boys into men: A cluster-randomized controlled trial of a dating violence prevention program.
      ,
      • Kervin D.
      • Obinna J.
      Youth action strategies in the primary prevention of teen dating violence.
      ]. As well, several studies have demonstrated increases in bystander self-efficacy [
      • Baker C.K.
      • Naai R.
      • Mitchell J.
      • Trecker C.
      Utilizing a train-the-trainer model for sexual violence prevention: Findings from a pilot study with high school students of Asian and Pacific Islander descent in Hawai‘i.
      ], skills [
      • Kervin D.
      • Obinna J.
      Youth action strategies in the primary prevention of teen dating violence.
      ], and intentions [
      • Baams L.
      • Dubas J.
      • van Aken M.
      Comprehensive sexuality education as a longitudinal predictor of LGBTQ name-calling and perceived willingness to intervene in school.
      ,
      • Miller E.
      • Tancredi D.J.
      • McCauley H.L.
      • et al.
      Coaching boys into men: A cluster-randomized controlled trial of a dating violence prevention program.
      ]. A systematic review of 7th- to 12th-grade bystander intervention programs suggests beneficial effects on bystander behaviors up to 4 months following the programs [
      • Kettry H.H.
      • Marx R.
      • Tanner-Smith E.
      Effects of bystander programs on the prevention of sexual assault among adolescents and college students: A systematic review.
      ]. An IPV prevention program in an alternative HS showed strong improvements in bystander skills, gender-equitable attitudes, and bystander interventions, leading to improved overall school climate and improvement in the external reputation of the school [
      • Kervin D.
      • Obinna J.
      Youth action strategies in the primary prevention of teen dating violence.
      ]. A strong randomized study of a coach-led intervention in 16 high schools increased intentions to intervene, improved gender-equitable attitudes, and improved bystander actions among male athletes, both at post-test and 1-year follow-up [
      • Miller E.
      • Tancredi D.J.
      • McCauley H.L.
      • et al.
      Coaching boys into men: A cluster-randomized controlled trial of a dating violence prevention program.
      ,
      • Miller E.
      • Tancredi D.J.
      • McCauley H.L.
      • et al.
      One-year follow-up of a coach-delivered dating violence prevention program: A cluster randomized controlled trial.
      ].

      Healthy Relationships

      Programs specifically designed to reduce dating and interpersonal violence often had broader healthy relationship concepts among their measured outcomes. This section, however, reviews healthy relationship outcomes outside the specific context of DV or IPV prevention programs. These efforts focused on healthy relationships as a foundation for adolescent sexual health [
      • Peskin M.F.
      • Markham C.M.
      • Shegog R.
      • et al.
      Effects of the it’s your game… keep it real program on dating violence in ethnic-minority middle school youths: A group randomized trial.
      ] and emphasized communication skills [
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ,
      • Rice T.M.
      • McGill J.
      • Adler-Baeder F.
      Relationship education for youth in high school: Preliminary evidence from a non-controlled study on dating behavior and parent-adolescent relationships.
      ,
      • Pick S.
      • Givaudan M.
      • Sirkin J.
      • Ortega I.
      Communication as a protective factor: Evaluation of a life skills HIV/AIDS prevention program for mexican elementary-school students.
      ,
      • Buote D.
      • Berglund P.
      Promoting social justice through building healthy relationships: Evaluation of SWOVA's "Respectful Relationships" program.
      ], ethics and social justice [
      • Baams L.
      • Dubas J.
      • van Aken M.
      Comprehensive sexuality education as a longitudinal predictor of LGBTQ name-calling and perceived willingness to intervene in school.
      ,
      • Constantine N.A.
      • Jerman P.
      • Berglas N.F.
      • et al.
      Short-term effects of a rights-based sexuality education curriculum for high-school students: A cluster-randomized trial.
      ,
      • Buote D.
      • Berglund P.
      Promoting social justice through building healthy relationships: Evaluation of SWOVA's "Respectful Relationships" program.
      ,
      • Lamb S.
      • Randazzo R.
      An examination of the effectiveness of a sexual ethics curriculum.
      ], and social–emotional learning [
      • Bates R.C.
      An action research study: Using classroom guidance lessons to teach middle school students about sexual harassment.
      ,
      • Pick S.
      • Givaudan M.
      • Sirkin J.
      • Ortega I.
      Communication as a protective factor: Evaluation of a life skills HIV/AIDS prevention program for mexican elementary-school students.
      ].

      Increased knowledge, attitudes, and skills

      Two important studies demonstrated improvements in knowledge and attitudes related to healthy relationships. In a one-group, repeated-measures design with 3,658 ninth graders, the Relationship Smarts curriculum demonstrated significant improvements in healthy relationship knowledge and dating skills, as well as improved relationship skills for parent–adolescent relationships, both at post-test and 1-year follow-up [
      • Rice T.M.
      • McGill J.
      • Adler-Baeder F.
      Relationship education for youth in high school: Preliminary evidence from a non-controlled study on dating behavior and parent-adolescent relationships.
      ]. Notably, knowledge about healthy relationships at baseline predicted improvements in parent–adolescent relationship scores at post-test, suggesting that knowledge in one relationship context has the potential to translate to other types of relationships. In addition, a peer-facilitated, five-session healthy relationship program for academically at-risk adolescents, adapted for cultural relevance in three metropolitan areas of Southeastern U.S., demonstrated strong improvements among ninth graders on knowledge and attitudes about healthy relationships [
      • McLeod D.A.
      • Jones R.
      • Cramer E.P.
      An evaluation of a school-based, peer-facilitated, healthy relationship program for at-risk adolescents.
      ].

      Improved communication skills and intentions

      Curricula that addressed communication within relationships resulted in improved communication skills and intentions, including increased intentions to discuss relationships and/or sex within relationships [
      • Wolfe D.A.
      • Crooks C.V.
      • Chiodo D.
      • et al.
      Observations of adolescent peer resistance skills following a classroom-based healthy relationship program: A post-intervention comparison.
      ,
      • Rice T.M.
      • McGill J.
      • Adler-Baeder F.
      Relationship education for youth in high school: Preliminary evidence from a non-controlled study on dating behavior and parent-adolescent relationships.
      ,
      • Pick S.
      • Givaudan M.
      • Sirkin J.
      • Ortega I.
      Communication as a protective factor: Evaluation of a life skills HIV/AIDS prevention program for mexican elementary-school students.
      ,
      • Lamb S.
      • Randazzo R.
      An examination of the effectiveness of a sexual ethics curriculum.
      ], and with parents and medical providers [
      • Scull T.M.
      • Malik C.V.
      • Kupersmidt J.B.
      A media literacy education approach to teaching adolescents comprehensive sexual health education.
      ]. A longitudinal study of 1,600 Mexican fourth graders, in the Yo Quiero Yo Puede program, which focused on the importance of talking about taboo and difficult subjects, demonstrated improved communication skills in these subjects and increased self-efficacy and intentions to discuss difficult subjects, including romance, sexuality, and threatening or unpleasant topics [
      • Pick S.
      • Givaudan M.
      • Sirkin J.
      • Ortega I.
      Communication as a protective factor: Evaluation of a life skills HIV/AIDS prevention program for mexican elementary-school students.
      ]. Rigorous evaluations found significant increases in communication skills for both the Respectful Relationships 6th to 10th grade sequential curriculum [
      • Buote D.
      • Berglund P.
      Promoting social justice through building healthy relationships: Evaluation of SWOVA's "Respectful Relationships" program.
      ], and the Fourth R, for ninth graders [
      • Wolfe D.A.
      • Crooks C.V.
      • Chiodo D.
      • et al.
      Observations of adolescent peer resistance skills following a classroom-based healthy relationship program: A post-intervention comparison.
      ].

      Child sex abuse prevention

      This review found strong evidence for the effectiveness of child sex abuse prevention efforts in elementary school. Such programs typically use behavioral practice and role-play [
      • Davis M.K.
      • Gidycz C.A.
      Child sexual abuse prevention programs: A meta-analysis.
      ] and encourage parental involvement [
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ,
      • Macintyre D.
      • Carr A.
      Evaluation of the effectiveness of the stay safe primary prevention programme for child sexual abuse.
      ]. They teach about body ownership and children's right to control their bodies [
      • Macintyre D.
      • Carr A.
      Evaluation of the effectiveness of the stay safe primary prevention programme for child sexual abuse.
      ] and about communication and self-protection [
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ,
      • Macintyre D.
      • Carr A.
      Evaluation of the effectiveness of the stay safe primary prevention programme for child sexual abuse.
      ]. A strong meta-analysis of 27 preschool through Grade 5 programs [
      • Davis M.K.
      • Gidycz C.A.
      Child sexual abuse prevention programs: A meta-analysis.
      ] and a systematic review of 24 K-5 programs [
      • Walsh K.
      • Zwi K.
      • Woolfenden S.
      • Shlonsky A.
      School-based education programs for the prevention of child sexual abuse: A cochrane systematic review and meta-analysis.
      ] demonstrate significant effects on a wide range of outcomes, including behaviors in simulated at-risk situations. Another large systematic review concluded that, in general, parental involvement, opportunities for practice, repeated exposure, and sensitivity to developmental level were key characteristics of effective child sex abuse programs [
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ].

      Improved knowledge, attitudes, skills and social–emotional outcomes related to personal safety and touch

      A systematic review of 22 North American and UK curricula for K-6 children found significant increases in knowledge across programs, improved self-protective skills, particularly among older elementary students, and emotional gains in self-esteem, self-efficacy, and feelings of safety, in approximately one third of the programs. Gains in knowledge and some social–emotional outcomes remained at 3- to 5-month follow-up [
      • Topping K.J.
      • Barron I.G.
      School-based child sexual abuse prevention programs: A review of effectiveness.
      ]. In a rigorous cluster randomized study of six New York City elementary schools, Safe Touches for second and third graders showed significant improvement in knowledge of safe touch [
      • Pulido M.L.
      • Dauber S.
      • Tully B.A.
      • et al.
      Knowledge gains following a child sexual abuse prevention program among urban students: A cluster-randomized evaluation.
      ]. Notably, intervention–control group differences were larger when “stranger danger” items were removed, suggesting that this curriculum was able to address inappropriate touch in a more nuanced way. Stay Safe primary prevention, for 7- and 10-year-olds in Ireland, demonstrated gains in knowledge, skills, and self-esteem, maintained at 3-month follow-up. Notably, gains were greatest for the younger students [
      • Macintyre D.
      • Carr A.
      Evaluation of the effectiveness of the stay safe primary prevention programme for child sexual abuse.
      ].
      Child abuse prevention programs for second to fourth graders demonstrated significant increases in knowledge of appropriate and inappropriate touch, what to do in an inappropriate situation [
      • Baker C.K.
      • Gleason K.
      • Naai R.
      • et al.
      Increasing knowledge of sexual abuse: A study with elementary school children in Hawai'i.
      ], and increased knowledge and skill to identify unsafe situations [
      • Hazzard A.
      • Webb C.
      • Kleemeier C.
      • et al.
      Child sexual abuse prevention: Evaluation and one-year follow-up.
      ]. A strong randomized study in 21 urban U.S. schools found gains were maintained at 1 year, with no increase in anxiety, concluding that it is safe to discuss sensitive subjects with young children, and demonstrating the value of early education [
      • Hazzard A.
      • Webb C.
      • Kleemeier C.
      • et al.
      Child sexual abuse prevention: Evaluation and one-year follow-up.
      ]. A kindergarten program showed significant improvement in knowledge of unsafe secrets and distinguishing between tattling and reporting [
      • Brown D.M.
      Evaluation of Safer, Smarter Kids: Child sexual abuse prevention curriculum for kindergartners.
      ], and another program conducted with 123 Latinx preschoolers demonstrated increased knowledge and skills at post-test and 3-month follow-up [
      • Kenny M.C.
      • Wurtele S.K.
      • Alonso L.
      Evaluation of a personal safety program with Latino preschoolers.
      ]. Studies in the U.S. and Canada [
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ] reported positive effects on sense of control and safety felt by children, including, in one, more positive feelings about their genitals (e.g., it's okay to touch one's own private parts).

      Improved disclosure skills and behaviors

      Several studies have demonstrated improvements in young children's skills and behaviors specifically related to disclosure [
      • Davis M.K.
      • Gidycz C.A.
      Child sexual abuse prevention programs: A meta-analysis.
      ,
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ,
      • Macintyre D.
      • Carr A.
      Evaluation of the effectiveness of the stay safe primary prevention programme for child sexual abuse.
      ,
      • Jin Y.
      • Chen J.
      • Jiang Y.
      • Yu B.
      Evaluation of a sexual abuse prevention education program for school-age children in China: A comparison of teachers and parents as instructors.
      ,
      • Kim S.-J.
      • Kang K.-A.
      Effects of the child sexual abuse prevention education (C-SAPE) program on South Korean fifth-grade students' competence in terms of knowledge and self-protective behaviors.
      ]. Evaluation of an early elementary sexual abuse prevention program in China focused on “no, go, and tell,” using random assignment by classroom to intervention and non-intervention groups, found significant increases for important skills related to reporting [
      • Jin Y.
      • Chen J.
      • Jiang Y.
      • Yu B.
      Evaluation of a sexual abuse prevention education program for school-age children in China: A comparison of teachers and parents as instructors.
      ]. Fifth graders in Child Sexual Abuse Prevention Education in South Korea [
      • Kim S.-J.
      • Kang K.-A.
      Effects of the child sexual abuse prevention education (C-SAPE) program on South Korean fifth-grade students' competence in terms of knowledge and self-protective behaviors.
      ] showed significant improvement in self-protective behaviors. A systematic review of childhood sex abuse curricula in the U.S. and Canada concluded that one of the most common effects was increased knowledge of a resource person to whom children would report abuse [
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ]. More important, behavioral outcomes included increased parent–child communication about child sex abuse, and when implemented with a group of children known to have been abused, increased disclosure.

      Additional outcomes

      Social–emotional learning

      Although not identified as a goal of sex education per se, the incorporation of social-emotional learning into sex education has been explored in the literature [
      • Cahill H.
      • Kern M.L.
      • Dadvand B.
      • et al.
      An integrative approach to evaluating the implementation of social and emotional learning and gender-based violence prevention education.
      ]. Studies identified here demonstrate a range of important social–emotional outcomes, across grade levels, resulting from sex education in the classroom, including increased empathy [
      • Richard G.
      • Vallerand O.
      • Petit M.P.
      • Charbonneau A.
      Discussing sexual orientation and gender in classrooms: A testimonial-based approach to fighting homophobia in schools.
      ,
      • Athanases S.Z.
      A gay-themed lesson in an ethnic literature curriculum: Tenth graders' responses to `Dear Anita'.
      ], respect for others [
      • Lucassen M.F.
      • Burford J.
      Educating for diversity: An evaluation of a sexuality diversity workshop to address secondary school bullying.
      ], improved communication [
      • Constantine N.A.
      • Jerman P.
      • Berglas N.F.
      • et al.
      Short-term effects of a rights-based sexuality education curriculum for high-school students: A cluster-randomized trial.
      ,
      • Foshee V.A.
      • Bauman K.E.
      • Greene W.F.
      • et al.
      The safe dates program: 1-year follow-up results.
      ,
      • Pick S.
      • Givaudan M.
      • Sirkin J.
      • Ortega I.
      Communication as a protective factor: Evaluation of a life skills HIV/AIDS prevention program for mexican elementary-school students.
      ,
      • Buote D.
      • Berglund P.
      Promoting social justice through building healthy relationships: Evaluation of SWOVA's "Respectful Relationships" program.
      ,
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ], managing feelings [
      • Foshee V.
      • Bauman K.E.
      • Arriaga X.B.
      • et al.
      An evaluation of safe dates, an adolescent dating violence prevention program.
      ], positive self-image (including body image) [
      • Macintyre D.
      • Carr A.
      Evaluation of the effectiveness of the stay safe primary prevention programme for child sexual abuse.
      ,
      • Topping K.J.
      • Barron I.G.
      School-based child sexual abuse prevention programs: A review of effectiveness.
      ,
      • Kater K.J.
      • Rohwer J.
      • Londre K.
      Evaluation of an upper elementary school program to prevent body image, eating, and weight concerns.
      ,
      • Halliwell E.
      • Yager Z.
      • Paraskeva N.
      • et al.
      Body image in primary schools: A pilot evaluation of a primary school intervention program designed by teachers to improve children's body satisfaction.
      ,
      • Dunstan C.J.
      • Paxton S.J.
      • McLean S.A.
      An evaluation of a body image intervention in adolescent girls delivered in single-sex versus co-educational classroom settings.
      ,
      • McCabe M.P.
      • Ricciardelli L.A.
      • Karantzas G.
      Impact of a healthy body image program among adolescent boys on body image, negative affect, and body change strategies.
      ,
      • Berman N.
      • White A.
      Refusing the Stereotype: Decoding negative gender imagery through a school-based digital media literacy program.
      ], increased sense of self-control and safety [
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ], and establishing and maintaining positive relationships [
      • Rice T.M.
      • McGill J.
      • Adler-Baeder F.
      Relationship education for youth in high school: Preliminary evidence from a non-controlled study on dating behavior and parent-adolescent relationships.
      ]. For example, evaluation of Respectful Relationships, a sequential, 4-year social justice program in Canada, with 1,748 6th to 10th graders, demonstrated significant growth in empathy, self-esteem, ability to speak one's opinion, belief in equal rights for all, and “seeing people for who they are on the inside.” In addition, the program demonstrated increased nonviolent conflict resolution among girls, and among boys, increased discomfort in seeing others being picked on [
      • Buote D.
      • Berglund P.
      Promoting social justice through building healthy relationships: Evaluation of SWOVA's "Respectful Relationships" program.
      ].

      Media literacy

      Similarly, media literacy is not commonly included in discussions about sex education outcomes, although it is recognized as an important life skill for young people. Two studies reviewed here, however, suggest that media literacy may be particularly important as an outcome within sex education. Two eighth grade programs using a media literacy approach [
      • Scull T.M.
      • Malik C.V.
      • Kupersmidt J.B.
      A media literacy education approach to teaching adolescents comprehensive sexual health education.
      ,
      • Berman N.
      • White A.
      Refusing the Stereotype: Decoding negative gender imagery through a school-based digital media literacy program.
      ] demonstrated increased media deconstruction skills, understanding of how media affects both sense of self and perceptions of teen norms, and, most notably, intentions for communication with parents, partners, and medical providers about sex.

      Discussion

      The purpose of this review was to understand whether achieving certain CSE goals is possible. The SLR aimed to triangulate findings from a wide range of peer-reviewed studies to identify evidence that supports educational approaches to improving adolescent sexual health and provides theoretical guidance for the broad goals of CSE. As such, we did not seek to identify or recommend specific programs or educational methodologies. Different settings, cultures, and local practices will dictate what specific approaches will ultimately be most effective and appropriate.
      There is ample evidence that the physical and emotional health of young people is related to their academic achievement, as healthier students are more likely to stay in school and achieve higher grades, whereas health-related problems may contribute to academic struggles including higher absenteeism and dropping out [
      • Basch C.E.
      Healthier students are better learners: A missing link in school reforms to close the achievement gap.
      ,
      • Townsend L.
      • Flisher A.J.
      • King G.
      A systematic review of the relationship between high school dropout and substance abuse.
      ,
      CDC
      Sexual risk behaviors and academic achievement.
      ,
      CDC
      Health-risk behaviors and academic achievement.
      ,
      CDC
      School connectedness: Strategies for increasing protective factors among youth.
      ,
      • Dilley J.
      Research review: School-based health interventions and academic achievement.
      ]. Evidence reviewed here highlights this point with respect to sexual health. That is, if students are able to avoid early pregnancy, STIs, sexual abuse, and interpersonal violence and harassment, while feeling safe and supported within their school environment, they are more likely to experience academic success, a foundation for future stability.
      This systematic review of the literature on sexual health outcomes from the past 30 years, provides encouraging documentation for the field of CSE. By setting aside studies looking strictly at pregnancy and STI prevention efforts, we were able to put a spotlight on critical CSE goals that often get lost in discussions about the impact of sex education on adolescent health. The findings reported here highlight important topics and approaches that show evidence of success, as well as areas of CSE that remain understudied. What this review found is that school-based CSE can lower homophobia and homophobic-related bullying, can increase understanding of gender and gender norms, can improve knowledge and skills that support healthy relationships, can build child sex abuse prevention skills, and can reduce dating and intimate partner violence.

      Support for early, scaffolded, and multigrade approaches

      This review offers substantial evidence that sexuality education is most effective when begun early and before sexual activity begins [
      • Pick S.
      • Givaudan M.
      • Sirkin J.
      • Ortega I.
      Communication as a protective factor: Evaluation of a life skills HIV/AIDS prevention program for mexican elementary-school students.
      ,
      • Davis M.K.
      • Gidycz C.A.
      Child sexual abuse prevention programs: A meta-analysis.
      ,
      • Macintyre D.
      • Carr A.
      Evaluation of the effectiveness of the stay safe primary prevention programme for child sexual abuse.
      ,
      • Walsh K.
      • Zwi K.
      • Woolfenden S.
      • Shlonsky A.
      School-based education programs for the prevention of child sexual abuse: A cochrane systematic review and meta-analysis.
      ,
      • Kater K.J.
      • Rohwer J.
      • Londre K.
      Evaluation of an upper elementary school program to prevent body image, eating, and weight concerns.
      ,
      • Halliwell E.
      • Yager Z.
      • Paraskeva N.
      • et al.
      Body image in primary schools: A pilot evaluation of a primary school intervention program designed by teachers to improve children's body satisfaction.
      ,
      • Gaskins S.W.
      • Beard S.R.
      • Wang M.Q.
      An HIV/AIDS education program for children in grades K-5.
      ,
      • Mueller T.E.
      • Gavin L.E.
      • Kulkarni A.
      The association between sex education and youth’s engagement in sexual intercourse, age at first intercourse, and birth control use at first sex.
      ,
      • Reading R.
      • Bissell S.
      • Goldhagen J.
      • et al.
      Promotion of children’s rights and prevention of child maltreatment.
      ]. As well, several studies, including some strong systematic reviews and meta-analyses, provide ample support for teaching that builds on previous lessons and/or grades and for programs of longer duration [
      • Bentley D.F.
      • Souto-Manning M.
      Toward inclusive understandings of marriage in an early childhood classroom: Negotiating (un)readiness, community, and vulnerability through a critical reading of "King and King".
      ,
      • Ryan C.L.
      • Patraw J.M.
      • Bednar M.
      Discussing princess boys and pregnant men: Teaching about gender diversity and transgender experiences within an elementary school curriculum.
      ,
      • Rice P.S.
      Creating spaces for boys and girls to expand their definitions of masculinity and femininity through children's literature.
      ,
      • Dutro E.
      "But That's a Girls' Book!" Exploring gender boundaries in children's reading practices.
      ,
      • Hermann-Wilmarth J.M.
      • Lannen R.
      • Ryan C.L.
      Critical literacy and transgender topics in an upper elementary classroom: A portrait of possibility.
      ,
      • Matthews C.E.
      • Binkley W.
      • Crisp A.
      • Gregg K.
      Challenging gender bias in fifth grade.
      ,
      • Smylie L.
      • Maticka-Tyndale E.
      • Boyd D.
      Evaluation of a school-based sex education programme delivered to grade nine students in Canada.
      ,
      • Constantine N.A.
      • Jerman P.
      • Berglas N.F.
      • et al.
      Short-term effects of a rights-based sexuality education curriculum for high-school students: A cluster-randomized trial.
      ,
      • Ting S.
      Meta-analysis on dating violence prevention among middle and high schools.
      ,
      • Crooks C.V.
      • Scott K.L.
      • Broll R.
      • et al.
      Does an evidence-based healthy relationships program for 9th graders show similar effects for 7th and 8th graders? Results from 57 schools randomized to intervention.
      ,
      • Kettry H.H.
      • Marx R.
      • Tanner-Smith E.
      Effects of bystander programs on the prevention of sexual assault among adolescents and college students: A systematic review.
      ,
      • Buote D.
      • Berglund P.
      Promoting social justice through building healthy relationships: Evaluation of SWOVA's "Respectful Relationships" program.
      ,
      • Kenny M.C.
      • Capri V.
      • Thakkar-Kolar R.
      • et al.
      Child sexual abuse: From prevention to self-protection.
      ,
      • Dinaj-Koci V.
      • Lunn S.
      • Deveaux L.
      • et al.
      Adolescent age at time of receipt of one or more sexual risk reduction interventions.
      ,
      • Mirzazadeh A.
      • Biggs M.A.
      • Viitanen A.
      • et al.
      Do school-based programs prevent HIV and other sexually transmitted infections in adolescents? A systematic review and meta-analysis.
      ]. As with all other areas of the curriculum, building an early foundation and scaffolding learning with developmentally appropriate content and teaching are key to long-term development of knowledge, attitudes, and skills that support healthy sexuality.
      CSE is designed to include all grade levels, K-12, and in the early grades, even in preschool, there seems to be little controversy or discomfort around discussions in the context of child sex abuse prevention. The literature on sexual abuse prevention efforts in early grades reviewed here shows strong evidence that young children can develop self-protective knowledge, skills, and intentions, including an increased likelihood of reporting sexual abuse and knowing how to respond in a dangerous situation, all without increasing anxiety. Other than in this area, though, there are only limited examples of sexuality-related content in the K-5 curriculum [
      Centers for Disease Control and Prevention
      Results from the school health policies and practices study 2014.
      ], many topics being deemed traumatizing, inappropriate, or premature for young children and thus remaining controversial [
      • Shalby C.
      Controversial sex education framework for California approved despite protest.
      ,
      The Associated Press
      Sex-education bill passes Washington House after fierce debate over its content, timing.
      ]. The data, however, strongly indicate that such topics are developmentally appropriate and produce positive outcomes, while providing a foundation for future learning. This review suggests that not only are younger children able to discuss sexuality-related issues but that the early grades may, in fact, be the best time to introduce topics related to sexual orientation, gender identity and expression, gender equality, and social justice related to the LGBTQ community before hetero- and cisnormative values and assumptions become more deeply ingrained and less mutable. Children learn gender role attitudes at an early age from observing the people in their families [
      • Bronstein P.
      The family environment: Where gender role socialization begins.
      ]. As they progress through school, these attitudes are further shaped by classmates and peers, as well as by the biases of teachers, the design of the curriculum, and the school environment [
      • Blakemore J.E.O.
      • Berenbaum S.A.
      • Liben L.S.
      Gender development.
      ,
      • Leaper C.
      • Bigler R.S.
      Gender.
      ]. Given the influence of this early socialization and learning, it is important to introduce concepts that would disrupt stereotypical and harmful biases related to gender and sexual orientation, during this formative time.

      Tackling homophobia, transphobia, and hostile school environments

      Particularly at-risk, LGBTQ students continue to face a hostile environment in school, routinely hearing anti-LGBTQ language and experiencing victimization and discrimination at school [
      • Kosciw J.G.
      • Greytak E.A.
      • Zongrone A.D.
      • et al.
      The 2017 National School Climate Survey: The experiences of lesbian, gay, bisexual, transgender, and queer youth in our nation’s schools.
      ]. These students have “worse educational outcomes and poorer psychological well-being,” experiencing lower self-esteem and higher rates of depression [
      • Kosciw J.G.
      • Greytak E.A.
      • Zongrone A.D.
      • et al.
      The 2017 National School Climate Survey: The experiences of lesbian, gay, bisexual, transgender, and queer youth in our nation’s schools.
      ]. Efforts to reduce homophobic bullying and harassment and to increase appreciation for sexual diversity can improve the school climate for all students, and, as this review found, create a safer environment that is more conducive to learning, and to better mental health for sexual minority students. Evidence of success was found from individual classroom efforts, as well as from inclusivity across the curriculum, in promoting a more accepting and welcoming environment for sexual minority youth.

      Social justice pedagogy

      The literature highlights both the efficacy and importance of addressing gender and sexual orientation within the context of human rights and equality [
      • Flowers S.C.
      Enacting our multidimensional power: Black women sex educators demonstrate the value of an intersectional sexuality education framework.
      ,
      • Berglas N.F.
      • Constantine N.A.
      • Ozer E.J.
      A rights-based approach to sexuality education: Conceptualization, clarification and challenges.
      ,
      • Schalet A.T.
      • Santelli J.S.
      • Russell S.T.
      • et al.
      Invited commentary: Broadening the evidence for adolescent sexual and reproductive health and education in the United States.
      ,
      • Garcia L.
      • Fields J.
      Renewed commitments in a time of vigilance: Sexuality education in the USA.
      ,
      • Flores G.
      Best not forget lesbian, gay, bisexual, and transgender themed children's literature: A teacher's reflections of a more inclusive multicultural education and literature program.
      ]. Helping young people to challenge the social structures and systems that lead to discrimination and oppression based on gender and sexual orientation is critical to their sexual, emotional, and social development. The evidence reviewed here suggests that expanding social justice pedagogy within the sex education curriculum beyond the topics of gender and sexual orientation makes sense as well, and that research on such efforts is much needed.

      Importance of social-emotional learning

      SEL has been found to improve academic outcomes and behaviors that confer real-life benefits among students from kindergarten through high school including improved classroom behavior, increased ability to manage challenging emotions, and better attitudes about themselves, others, and school [
      • Durlak J.A.
      • Weissberg R.P.
      • Dymnicki A.B.
      • et al.
      The impact of enhancing students’ social and emotional learning: A meta-analysis of school based universal interventions.
      ,
      • Weissberg R.P.
      Promoting the social and emotional learning of millions of school children.
      ,
      • Mahoney J.L.
      • Durlak J.A.
      • Weissberg R.P.
      An update on social and emotional learning outcome research.
      ]. The findings from this review suggest that CSE represents a critical component of SEL and outcomes. Given that, it is essential that core SEL competencies be proactively integrated into school-based sex education efforts [
      Collaborative for Academic, Social, and Emotional Learning (CASEL)
      Core SEL competencies.
      ], and measured in any assessments.

      Sex education across the curriculum

      It is worth noting that in this review, many of the positive outcomes and promising approaches that worked toward creating affirming, inclusive school environments occurred not in traditional health or sex education classes, but in social studies, English, physical education, mathematics, music, and art. In particular, the vast majority of successful approaches to LGBTQ and gender norm topics in the elementary school grades used literature with students as the entry point for learning and discussion, most with the goal of increasing appreciation and acceptance of sexual and gender diversity [
      • Schall J.
      • Kauffmann G.
      Exploring literature with gay and lesbian characters in the elementary school.
      ,
      • Bentley D.F.
      • Souto-Manning M.
      Toward inclusive understandings of marriage in an early childhood classroom: Negotiating (un)readiness, community, and vulnerability through a critical reading of "King and King".
      ,
      • Ryan C.L.
      • Patraw J.M.
      • Bednar M.
      Discussing princess boys and pregnant men: Teaching about gender diversity and transgender experiences within an elementary school curriculum.
      ,
      • Rice P.S.
      Creating spaces for boys and girls to expand their definitions of masculinity and femininity through children's literature.
      ,
      • Dutro E.
      "But That's a Girls' Book!" Exploring gender boundaries in children's reading practices.
      ,
      • Hermann-Wilmarth J.M.
      • Lannen R.
      • Ryan C.L.
      Critical literacy and transgender topics in an upper elementary classroom: A portrait of possibility.
      ]. The fact that topics falling within sex education can be addressed successfully across the curriculum is encouraging and offers much needed flexibility to schools, both in terms of available time and talented teachers to tackle difficult and important topics. It also provides an opportunity to explore sexuality-related issues in different contexts and by applying a variety of lenses. Given that most schools have limited time allotted to health or sex education [], a coordinated and concerted effort to teach and reinforce important sexual health concepts throughout other areas of the curriculum is a promising strategy.

      Unmet needs

      Several areas of focus are notably absent from the evaluation literature. Two topics often excluded from curricula, and therefore not included in outcome evaluations, are pleasure and desire [
      • Lamb S.
      • Lustig K.
      • Graling K.
      The use and misuse of pleasure in sex education curricula.
      ,
      • Jolly S.
      Positive approaches to sexuality and new normative frames: Strands of research and action in China and the USA.
      ]; most sex education is focused on sex as a problem behavior. The literature suggests that there is a need for, but little evidence of, teaching that views teen sex as normative, rather than pathological [
      • Laina B.C.
      The Trouble of Teen: Sex the construction of adolescent sexuality through school-based sexuality education.
      ,
      • Schalet A.
      Beyond abstinence and risk: A new paradigm for adolescent sexual health.
      ,
      • Michaud P.-A.
      Adolescents and risks: Why not change our paradigm?.
      ]. Furthermore, a few studies have concluded that it is not sexual behavior, per se, but the lack of a relationship context when it occurs, that is predictive of poor school outcomes [
      • Shoveller J.A.
      • Johnson J.L.
      • Langille D.B.
      • Mitchell T.
      Socio-cultural influences on young people’s seuxal development.
      ,
      • Bill M.
      • Eric G.
      Sex and school: Adolescent sexual intercourse and education.
      ]. Yet, the focus on sexual behavior as problematic itself eliminates the opportunity for young people to explore and experience normal, healthy, safe, and pleasurable sexual activity.
      It is important to note that much of the dating violence and IPV prevention literature focuses on programs that are traditionally gendered, that is, most do not address IPV specific to sexual minority youth. As schools begin to demonstrate greater acknowledgment of nonbinary gender identities, hopefully this change will be reflected in future research. Some studies have demonstrated that mixed gender interventions have stronger outcomes than interventions conducted in single-gender groups [
      • Pacifici C.
      • Stoolmiller M.
      • Nelson C.
      Evaluating a prevention program for teenagers on sexual coercion: A differential effectiveness approach.
      ,
      • Clinton-Sherrod A.M.
      • Morgan-Lopez A.A.
      • Gibbs D.
      • et al.
      Factors contributing to the effectiveness of four school-based sexual violence interventions.
      ]. Thus, more research on programs with expansive gender paradigms is needed, given that single-gender and gender-binary interventions have the potential to further victimize gender-nonconforming, nonbinary youth.
      Two studies specifically noted that children with disabilities were excluded from analyses [
      • Topping K.J.
      • Barron I.G.
      School-based child sexual abuse prevention programs: A review of effectiveness.
      ] or that outcomes were weaker for schools that had a higher proportion of classified students [
      • Pulido M.L.
      • Dauber S.
      • Tully B.A.
      • et al.
      Knowledge gains following a child sexual abuse prevention program among urban students: A cluster-randomized evaluation.
      ]. Although there has been increasing focus on this diverse population, with curricula and guidance for teaching young people with disabilities [
      Respect Ability
      Sexual education resources.
      ], there is limited literature that has attempted to evaluate the effectiveness of such approaches. Yet, young people with intellectual or physical disabilities may be at greater risk for poor sexual health including sexual abuse and exploitation, pregnancy and STIs, and difficulty forging and maintaining healthy relationships [
      • Treacy A.C.
      • Taylor S.S.
      • Abernathy T.V.
      Sexual health education for individuals with disabilities: A call to action.
      ,
      • Schaafsma D.
      • Kok G.
      • Stoffelen J.M.
      • Curfs L.M.
      Identifying effective methods for teaching sex education to individuals with intellectual disabilities: A systematic review.
      ,
      • Alriksson-Schmidt A.I.
      • Armour B.S.
      • Thibadeau J.K.
      Are adolescent girls with a physical disability at increased risk for sexual violence?.
      ]. The findings of this review suggest a strong need for evaluations focused on sex education efforts with these learners.
      The updated NSES [
      Future of Sex Education Initiative
      National sex education standards: Core content and skills, K-12.
      ] stress that sex education must be taught within the larger context of intersectionality, that is, the fact that young people cross a variety of sexual orientation, gender identity, racial, ethnic/cultural, and other groups. Sex education researchers have also raised this important point [
      • Flowers S.C.
      Enacting our multidimensional power: Black women sex educators demonstrate the value of an intersectional sexuality education framework.
      ,
      • Berglas N.F.
      • Constantine N.A.
      • Ozer E.J.
      A rights-based approach to sexuality education: Conceptualization, clarification and challenges.
      ,
      • Schalet A.T.
      • Santelli J.S.
      • Russell S.T.
      • et al.
      Invited commentary: Broadening the evidence for adolescent sexual and reproductive health and education in the United States.