Effects of a social-emotional and character development program on the trajectory of behaviors associated with social-emotional and character development: findings from three randomized trials

Gender, racial-ethnic, and socioeconomic disparities in the development of social-emotional competence among elementary school students

Social-emotional competence (SEC) has been demonstrated to be a crucial factor for student mental health and is malleable through the high-quality implementation of effective school-based social and emotional learning (SEL) programs. SEL is now widely practiced in the United States as a Tier 1 strategy for the entire student body, yet it remains unclear whether disparities exist in the development of SEC across socio-culturally classified subgroups of students. Also, despite the field's widespread concern about teacher bias in assessing SEC within diverse student bodies, little evidence is available on the measurement invariance of the SEC assessment tools used to explore and facilitate SEC development. Based on a sociocultural view of student SEC development, this study aimed to measure and examine the extent to which gender, racial-ethnic, and socioeconomic disparities exist in SEC developmental trajectories during elementary school years. Specifically, using 3 years of SEC assessment data collected from a districtwide SEL initiative (N = 5452; Grades K-2 at baseline; nine measurement occasions), this study (a) tested the measurement invariance of a widely-used, teacher-rated SEC assessment tool (DESSA-Mini) across student gender, race and ethnicity, and socioeconomic status (SES); and (b) examined the extent to which multiyear SEC growth trajectories differed across these subgroups under a routine SEL practice condition. The invariance testing results supported strict factorial invariance of the DESSA-Mini across all the examined subgroups, thereby providing a foundation for valid cross-group comparisons of student SEC growth. The piecewise latent growth modeling results indicated that boys (vs. girls), Black students (vs. White students), Hispanic students (vs. White students), and low-income students (vs. middle-to-high-income students) started with a lower level of SEC, with these gaps being sustained or slightly widened throughout 3 elementary school years. Based on these findings, this study calls for future research that can inform practice efforts to ensure equitable SEC assessments and produce more equitable SEL outcomes, thereby promoting equity in school mental health.

A Strategic Plan for Strengthening America's Families: A Brief from the Coalition of Behavioral Science Organizations

Despite significant progress in research on the treatment and prevention of psychological, behavioral, and health problems, the translation of this knowledge into population-wide benefit remains limited. This paper reviews the state of America’s children and families, highlighting the influence of stressful contextual and social conditions on child and family well-being and the concentration of disadvantage in numerous neighborhoods and communities throughout the nation. It then briefly reviews the progress that has been made in pinpointing policies that can reduce stressful contextual conditions such as poverty, discrimination, and the marketing of unhealthful foods and substances. It also describes numerous family and school interventions that have proven benefit in preventing psychological and behavioral problems as diverse as tobacco, alcohol, and other drug use; depression; antisocial behavior; academic failure; obesity prevention; and early childbearing. We argue that progress in translating existing knowledge into widespread benefit will require a nationwide effort to intervene comprehensively in neighborhoods and communities of concentrated disadvantage. We present a strategic plan for how such an effort could be organized. The first step in this organizing would be the creation of a broad and diverse coalition of organizations concerned with advancing public health and well-being. Such a coalition could increase public support both for the policies needed to focus on these disadvantaged areas and the research needed to incrementally improve our ability to help these areas.

Childhood Protective Factors and a Prevention Program Reduce Later Problem Behaviors

Prior research has yet to elucidate how constellations of protective factors in childhood and prevention efforts simultaneously may influence youth involvement in problem behaviors across different points in development. The current study examines how latent classes of social and emotional learning (SEL) skills, parent-child relationships, and peer influences in third grade and receipt of an ongoing SEL intervention predict substance use and violence in fifth and eighth grade. The urban, predominantly low-income, sample (N = 1,169) was nested in 14 schools that were randomly assigned to the Positive Action program or business-as-usual. Membership in a latent class reflecting protective childhood factors predicted less substance use and violence in fifth grade; however, the SEL program predicted less substance use and violence in eighth grade. Findings generally support that SEL interventions can successfully target and boost developmentally appropriate positive behaviors and can prevail over initial risk factors with enough time and exposure.

Individual-, family-, and school-level interventions targeting multiple risk behaviours in young people

BACKGROUND

Engagement in multiple risk behaviours can have adverse consequences for health during childhood, during adolescence, and later in life, yet little is known about the impact of different types of interventions that target multiple risk behaviours in children and young people, or the differential impact of universal versus targeted approaches. Findings from systematic reviews have been mixed, and effects of these interventions have not been quantitatively estimated.

OBJECTIVES

To examine the effects of interventions implemented up to 18 years of age for the primary or secondary prevention of multiple risk behaviours among young people.

SEARCH METHODS

We searched 11 databases (Australian Education Index; British Education Index; Campbell Library; Cumulative Index to Nursing and Allied Health Literature (CINAHL); Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library; Embase; Education Resource Information Center (ERIC); International Bibliography of the Social Sciences; MEDLINE; PsycINFO; and Sociological Abstracts) on three occasions (2012, 2015, and 14 November 2016)). We conducted handsearches of reference lists, contacted experts in the field, conducted citation searches, and searched websites of relevant organisations.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), including cluster RCTs, which aimed to address at least two risk behaviours. Participants were children and young people up to 18 years of age and/or parents, guardians, or carers, as long as the intervention aimed to address involvement in multiple risk behaviours among children and young people up to 18 years of age. However, studies could include outcome data on children > 18 years of age at the time of follow-up. Specifically,we included studies with outcomes collected from those eight to 25 years of age. Further, we included only studies with a combined intervention and follow-up period of six months or longer. We excluded interventions aimed at individuals with clinically diagnosed disorders along with clinical interventions. We categorised interventions according to whether they were conducted at the individual level; the family level; or the school level.

DATA COLLECTION AND ANALYSIS

We identified a total of 34,680 titles, screened 27,691 articles and assessed 424 full-text articles for eligibility. Two or more review authors independently assessed studies for inclusion in the review, extracted data, and assessed risk of bias.We pooled data in meta-analyses using a random-effects (DerSimonian and Laird) model in RevMan 5.3. For each outcome, we included subgroups related to study type (individual, family, or school level, and universal or targeted approach) and examined effectiveness at up to 12 months' follow-up and over the longer term (> 12 months). We assessed the quality and certainty of evidence using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included in the review a total of 70 eligible studies, of which a substantial proportion were universal school-based studies (n = 28; 40%). Most studies were conducted in the USA (n = 55; 79%). On average, studies aimed to prevent four of the primary behaviours. Behaviours that were most frequently addressed included alcohol use (n = 55), drug use (n = 53), and/or antisocial behaviour (n = 53), followed by tobacco use (n = 42). No studies aimed to prevent self-harm or gambling alongside other behaviours.Evidence suggests that for multiple risk behaviours, universal school-based interventions were beneficial in relation to tobacco use (odds ratio (OR) 0.77, 95% confidence interval (CI) 0.60 to 0.97; n = 9 studies; 15,354 participants) and alcohol use (OR 0.72, 95% CI 0.56 to 0.92; n = 8 studies; 8751 participants; both moderate-quality evidence) compared to a comparator, and that such interventions may be effective in preventing illicit drug use (OR 0.74, 95% CI 0.55 to 1.00; n = 5 studies; 11,058 participants; low-quality evidence) and engagement in any antisocial behaviour (OR 0.81, 95% CI 0.66 to 0.98; n = 13 studies; 20,756 participants; very low-quality evidence) at up to 12 months' follow-up, although there was evidence of moderate to substantial heterogeneity (I² = 49% to 69%). Moderate-quality evidence also showed that multiple risk behaviour universal school-based interventions improved the odds of physical activity (OR 1.32, 95% CI 1.16 to 1.50; I² = 0%; n = 4 studies; 6441 participants). We considered observed effects to be of public health importance when applied at the population level. Evidence was less certain for the effects of such multiple risk behaviour interventions for cannabis use (OR 0.79, 95% CI 0.62 to 1.01; P = 0.06; n = 5 studies; 4140 participants; I² = 0%; moderate-quality evidence), sexual risk behaviours (OR 0.83, 95% CI 0.61 to 1.12; P = 0.22; n = 6 studies; 12,633 participants; I² = 77%; low-quality evidence), and unhealthy diet (OR 0.82, 95% CI 0.64 to 1.06; P = 0.13; n = 3 studies; 6441 participants; I² = 49%; moderate-quality evidence). It is important to note that some evidence supported the positive effects of universal school-level interventions on three or more risk behaviours.For most outcomes of individual- and family-level targeted and universal interventions, moderate- or low-quality evidence suggests little or no effect, although caution is warranted in interpretation because few of these studies were available for comparison (n ≤ 4 studies for each outcome).Seven studies reported adverse effects, which involved evidence suggestive of increased involvement in a risk behaviour among participants receiving the intervention compared to participants given control interventions.We judged the quality of evidence to be moderate or low for most outcomes, primarily owing to concerns around selection, performance, and detection bias and heterogeneity between studies.

AUTHORS' CONCLUSIONS

Available evidence is strongest for universal school-based interventions that target multiple- risk behaviours, demonstrating that they may be effective in preventing engagement in tobacco use, alcohol use, illicit drug use, and antisocial behaviour, and in improving physical activity among young people, but not in preventing other risk behaviours. Results of this review do not provide strong evidence of benefit for family- or individual-level interventions across the risk behaviours studied. However, poor reporting and concerns around the quality of evidence highlight the need for high-quality multiple- risk behaviour intervention studies to further strengthen the evidence base in this field.

Intergenerational Continuity in Cannabis Use: The Role of Parent's Early Onset and Lifetime Disorder on Child's Early Onset

PURPOSE

Children's early onset of cannabis use was examined as a function of their parent's early onset of cannabis and subsequent incidence of a lifetime cannabis abuse or dependence disorder.

METHODS

Prospective, longitudinal data from the Rochester Youth Development Study and the Rochester Intergenerational Study for 442 parent-child dyads (274 father-child, 168 mother-child) were used. The children were evenly split by sex. Logistic regression models and a path analysis were estimated to assess the effect of parent's cannabis use on child's onset of cannabis by age 15.

RESULTS

Fathers who began using cannabis by age 15 were more likely to meet the criteria for a lifetime cannabis disorder (odds ratio = 5.66, 95% confidence interval = 1.89-16.90). The offspring of fathers who met the criteria for a disorder had higher odds of early initiation of cannabis use (odds ratio = 9.70, 95% confidence interval = 3.00-31.34). Early-onset cannabis use by father was indirectly associated with their child's onset of cannabis use via father's lifetime cannabis disorder. No significant effects for mothers were observed, although analyses were limited due to the low rate of mothers who met the criteria for a lifetime cannabis disorder.

CONCLUSIONS

This study provides evidence of intergenerational continuity in cannabis use among fathers and their children and confirms the need to consider timing of use and intervening mechanisms in the study of continuity in cannabis use across generations.

Can Universal SEL Programs Benefit Universally? Effects of the Positive Action Program on Multiple Trajectories of Social-Emotional and Misconduct Behaviors

Behavioral trajectories during middle childhood are predictive of consequential outcomes later in life (e.g., substance abuse, violence). Social and emotional learning (SEL) programs are designed to promote trajectories that reflect both growth in positive behaviors and inhibited development of negative behaviors. The current study used growth mixture models to examine effects of the Positive Action (PA) program on behavioral trajectories of social-emotional and character development (SECD) and misconduct using data from a cluster-randomized trial that involved 14 schools and a sample of predominately low-income, urban youth followed from 3rd through 8th grade. For SECD, findings indicated that PA was similarly effective at improving trajectories within latent classes characterized as "high/declining" and "low/stable". Favorable program effects were likewise evident to a comparable degree for misconduct across observed latent classes that reflected "low/rising" and "high/rising" trajectories. These findings suggest that PA and perhaps other school-based universal SEL programs have the potential to yield comparable benefits across subgroups of youth with differing trajectories of positive and negative behaviors, making them promising strategies for achieving the intended goal of school-wide improvements in student outcomes.

Effects of a School-Based Social-Emotional and Character Development Program on Health Behaviors: A Matched-Pair, Cluster-Randomized Controlled Trial

There is considerable research that suggests that school-based social-emotional programs can foster improved mental health and reduce problem behaviors for participating youth; in contrast, much less is known about the impact of these programs on physical health, even though some of these programs also include at least limited direct attention to promoting physical health behaviors. We examined the effects of one such program, Positive Action (PA), on physical health behaviors and body mass index (BMI), and tested for mediation of program effects through a measure of social-emotional and character development (SECD). Participating schools in the matched-pair, cluster-randomized trial were 14 low-performing K-8 Chicago Public Schools. We followed a cohort of students in each school from grades 3 to 8 (eight waves of data collection; 1170 total students). Student self-reports of health behaviors served as the basis for measures of healthy eating and exercise, unhealthy eating, personal hygiene, consistent bedtime, and SECD. We collected height and weight measurements at endpoint to calculate age- and gender-adjusted BMI z-scores. Longitudinal multilevel modeling analyses revealed evidence of favorable program effects on personal hygiene [effect size (ES) = 0.48], healthy eating and exercise (ES = 0.21), and unhealthy eating (ES = -0.19); in addition, BMI z-scores were lower among students in PA schools at endpoint (ES = -0.21). Program effects were not moderated by either gender or student mobility. Longitudinal structural equation modeling demonstrated mediation through SECD for healthy eating and exercise, unhealthy eating, and personal hygiene. Findings suggest that a SECD program without a primary focus on health behavior promotion can have a modest impact on outcomes in this domain during the childhood to adolescence transition.

A Longitudinal Evaluation of the Positive Action Program in a Low-Income, Racially Diverse, Rural County: Effects on Self-Esteem, School Hassles, Aggression, and Internalizing Symptoms

Positive Action is a school-based program that aims to decrease problem behaviors (e.g., violence, substance use) and increase positive behaviors (e.g., school engagement, academic achievement). Although a number of studies have shown that Positive Action successfully achieves these goals, few studies have evaluated the program's effectiveness in rural schools. Given that rural youth are at an increased risk for risky behaviors (e.g., violence, substance use), this is a critical gap in the existing Positive Action research base. The current study assesses the impact of Positive Action on change rates of self-esteem, school hassles, aggression, and internalizing symptoms in a group (N = 1246, 52% female) of ethnically/racially diverse (27% White, 23% African American, 12% mixed race/other, 8% Latino, 30% as American Indian) middle school youth (age range 9-20) located in two violent, low-income rural counties in North Carolina. One county engaged in Positive Action over the 3-year study window while the other county did not. Following multiple imputation and propensity score analysis, 4 two-level hierarchical linear models were run using each of the outcome measures as dependent variables. The results indicate that the program generates statistically significant beneficial effects for youth from the intervention county on self-esteem scores and school hassles scores. Although the program generates beneficial effects for intervention youth on the change in aggression scores, the finding is not statistically significant. The finding on the change in internalizing scores shows a non-significant detrimental effect: the youth from the comparison county have lower internalizing scores than those from the intervention county. Implications are discussed.

Effects of a youth substance use prevention program on stealing, fighting, and weapon use

Using a sample of sixth graders in 11 public schools in a large Southwestern city, this longitudinal study examined how a model substance use prevention program, keepin' it REAL, that was implemented in 7th grade, influenced three other problem behaviors (fighting, weapon use, stealing), measured in 8th grade. Using a non-equivalent control group design, we compared 259 students in the intervention to 322 students in a treatment-as-usual condition. At baseline, 37% of the sample reported fighting in the last 30 days; 31% reported stealing in the last 30 days, and 16% reported using a weapon in the last 30 days. Regression analyses adjusted for students nested in schools through multi-level modeling and for missing data through multiple imputation. We found that at posttest the rates of all three behaviors were lower in the intervention group than the control group at posttest: 35 versus 37% got into a fight in the last 30 days; 24 versus 31% stole something in the last 30 days; and 16 versus 25% used a weapon in the last 30 days. The program impact for fighting and stealing was not statistically significant and involved minimal effect sizes. The program impact for weapon use was not statistically significant but had an effect size comparable to that for other problem behavior interventions. Promoting positive development via life skills may be a key to broadening program impact.

Effects of the Positive Action Program on Indicators of Positive Youth Development Among Urban Youth

This study evaluated effects of Positive Action, a school-based social-emotional and character development (SECD) intervention, on indicators of positive youth development (PYD) among a sample of low-income, ethnic minority youth attending 14 urban schools. The study used a matched-pair, cluster-randomized controlled design at the school level. A multiple-measure self-report protocol assessed four key strengths and resources for PYD: self-concept, peer affiliations, ethics, and social skills. Students (n=1170) were assessed from grades 3 to 8, the duration of the intervention, with drop-outs and late entrants included in analyses. Growth curve analyses revealed evidence of favorable program effects on each of the four types of resources. The study contributes to PYD research by providing evidence for school-based interventions in low-income, urban contexts for ethnic minority youth.

The WHO Health Promoting School framework for improving the health and well-being of students and their academic achievement

BACKGROUND

The World Health Organization's (WHO's) Health Promoting Schools (HPS) framework is an holistic, settings-based approach to promoting health and educational attainment in school. The effectiveness of this approach has not been previously rigorously reviewed.

OBJECTIVES

To assess the effectiveness of the Health Promoting Schools (HPS) framework in improving the health and well-being of students and their academic achievement.

SEARCH METHODS

We searched the following electronic databases in January 2011 and again in March and April 2013: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, CINAHL, Campbell Library, ASSIA, BiblioMap, CAB Abstracts, IBSS, Social Science Citation Index, Sociological Abstracts, TRoPHI, Global Health Database, SIGLE, Australian Education Index, British Education Index, Education Resources Information Centre, Database of Education Research, Dissertation Express, Index to Theses in Great Britain and Ireland, ClinicalTrials.gov, Current controlled trials, and WHO International Clinical Trials Registry Platform. We also searched relevant websites, handsearched reference lists, and used citation tracking to identify other relevant articles.

SELECTION CRITERIA

We included cluster-randomised controlled trials where randomisation took place at the level of school, district or other geographical area. Participants were children and young people aged four to 18 years, attending schools or colleges. In this review, we define HPS interventions as comprising the following three elements: input to the curriculum; changes to the school's ethos or environment or both; and engagement with families or communities, or both. We compared this intervention against schools that implemented either no intervention or continued with their usual practice, or any programme that included just one or two of the above mentioned HPS elements.

DATA COLLECTION AND ANALYSIS

At least two review authors identified relevant trials, extracted data, and assessed risk of bias in the trials. We grouped different types of interventions according to the health topic targeted or the approach used, or both. Where data permitted, we performed random-effects meta-analyses to provide a summary of results across studies.

MAIN RESULTS

We included 67 eligible cluster trials, randomising 1443 schools or districts. This is made up of 1345 schools and 98 districts. The studies tackled a range of health issues: physical activity (4), nutrition (12), physical activity and nutrition combined (18), bullying (7), tobacco (5), alcohol (2), sexual health (2), violence (2), mental health (2), hand-washing (2), multiple risk behaviours (7), cycle-helmet use (1), eating disorders (1), sun protection (1), and oral health (1). The quality of evidence overall was low to moderate as determined by the GRADE approach. 'Risk of bias' assessments identified methodological limitations, including heavy reliance on self-reported data and high attrition rates for some studies. In addition, there was a lack of long-term follow-up data for most studies.We found positive effects for some interventions for: body mass index (BMI), physical activity, physical fitness, fruit and vegetable intake, tobacco use, and being bullied. Intervention effects were generally small but have the potential to produce public health benefits at the population level. We found little evidence of effectiveness for standardised body mass index (zBMI) and no evidence of effectiveness for fat intake, alcohol use, drug use, mental health, violence and bullying others; however, only a small number of studies focused on these latter outcomes. It was not possible to meta-analyse data on other health outcomes due to lack of data. Few studies provided details on adverse events or outcomes related to the interventions. In addition, few studies included any academic, attendance or school-related outcomes. We therefore cannot draw any clear conclusions as to the effectiveness of this approach for improving academic achievement.

AUTHORS' CONCLUSIONS

The results of this review provide evidence for the effectiveness of some interventions based on the HPS framework for improving certain health outcomes but not others. More well-designed research is required to establish the effectiveness of this approach for other health topics and academic achievement.

SOCIO-EMOTIONAL AND CHARACTER DEVELOPMENT: A Theoretical Orientation

More and more researchers are studying socio-emotional and character development (SECD). The rise and progress in SECD research is encouraging, but there is a critical issue with such a multidisciplinary and fast-developing field: SECD research and evaluation can be more consistent to prevent heterogeneity in definitions and disparate theoretical, measurement, and program models. After summarizing SECD-related literature, I recommend the theory of triadic influence (TTI) as a force to generate consistency and a resource to assist in guiding the design and evaluation of SECD-related programs. The theory fills a gulf in the literature that seeks an ecological theory aligned with SECD-related programs and etiology. The recommendation of the TTI stems from 3 main advantages: (1) The TTI integrates a full range of risk and protective factors in a detailed mediation and moderation framework; (2) it takes a comprehensive view of all the stakeholders in the educational system (i.e., youth, schools, families, and communities); (3) and its utility has been substantiated by empirical evidence from a variety of fields. I discuss applications of the TTI in SECD-related work and suggest improvements for etiology research and the design and evaluation of SECD programs.

Using social-emotional and character development to improve academic outcomes: a matched-pair, cluster-randomized controlled trial in low-income, urban schools

BACKGROUND

School-based social-emotional and character development (SECD) programs can influence not only SECD but also academic-related outcomes. This study evaluated the impact of one SECD program, Positive Action (PA), on educational outcomes among low-income, urban youth.

METHODS

The longitudinal study used a matched-pair, cluster-randomized controlled design. Student-reported disaffection with learning and academic grades, and teacher ratings of academic ability and motivation were assessed for a cohort followed from grades 3 to 8. Aggregate school records were used to assess standardized test performance (for entire school, cohort, and demographic subgroups) and absenteeism (entire school). Multilevel growth-curve analyses tested program effects.

RESULTS

PA significantly improved growth in academic motivation and mitigated disaffection with learning. There was a positive impact of PA on absenteeism and marginally significant impact on math performance of all students. There were favorable program effects on reading for African American boys and cohort students transitioning between grades 7 and 8, and on math for girls and low-income students.

CONCLUSIONS

A school-based SECD program was found to influence academic outcomes among students living in low-income, urban communities. Future research should examine mechanisms by which changes in SECD influence changes in academic outcomes.

Preventing negative behaviors among elementary-school students through enhancing students' social-emotional and character development

PURPOSE

Examine the effects of a comprehensive, school-wide social-emotional and character development program using a positive youth development perspective. Specifically, we examined a mediation mechanism whereby positive academic-related behaviors mediated the intervention effects on substance use, violence, and sexual activity.

DESIGN

Matched-pair, cluster-randomized, controlled design.

SETTING

Twenty (10 intervention and 10 control) racially/ethnically diverse schools in Hawaii.

SUBJECTS

Elementary-aged students (N = 1784) from grade 5.

INTERVENTION

The Positive Action program.

MEASURES

Students self-reported their academic behaviors, together with their substance use, violence, and voluntary sexual activity; teachers rated students' academic behaviors, substance use, and violence.

ANALYSIS

Structural equation modeling.

RESULTS

Students attending intervention schools reported significantly better academic behavior (B = .273, SE = .039, p < .001) and significantly less substance use (B = -.970, SE = .292, p < .01, incidence-rate ratio [IRR] = .379), violence (B = -1.410, SE = .296, p < .001, IRR = .244), and sexual activity (B = -2.415, SE = .608, p < .001, odds ratio = .089); boys reported more negative behaviors than girls. Intervention effects on student-reported substance use, violence, and sexual activity were mediated by positive academic behavior. Teacher reports corroborated these results, with rated academic behavior partially mediating the effects of the intervention on rated negative behaviors.

CONCLUSION

This study (1) provides evidence that adds insight into one mechanism through which a social-emotional and character development program affects negative outcomes and (2) supports social-emotional and character development and positive youth development perspectives that posit that focusing on youths' assets may reduce negative behaviors.

Direct and Mediated Effects of a Social-Emotional and Character Development Program on Adolescent Substance Use

Mitigating and preventing substance use among adolescents requires approaches that address the multitude of factors that influence this behavior. Such approaches must be tested, not only for evidence of empirical effectiveness, but also to determine the mechanisms by which they are successful. The aims of the present study were twofold: 1) To determine the effectiveness of a school-based social-emotional and character development (SECD) program, Positive Action (PA), in reducing substance use (SU) among a sample of U.S. youth living in a low-income, urban environment, and 2) to test one mechanism by which the program achieves its success. We used longitudinal mediation analysis to test the hypotheses that: 1) students attending PA intervention schools engage in significantly less SU than students attending control schools, 2) students attending PA intervention schools show significantly better change in SECD than students attending control schools, and 3) the effect of the PA intervention on SU is mediated by the change in SECD. Analyses revealed program effects on both SECD and SU, a relationship between SECD and SU, and the effects of PA on SU were completely mediated by changes in SECD. Future research directions and implications for school-based social-emotional and character development efforts and substance use prevention are addressed.