In the past decade, a variety of universal school-based social and emotional learning (SEL) programs have been designed to help improve children's social-emotional and cognitive skills. Recently there has been rapid expansion in the implementation of SEL services in elementary schools. This effort has been driven by the increasing recognition that the most effective interventions do not focus on academic instruction or risk alone, but take an integrative, holistic approach to provide more coordinated, sustained, and systematic services that are universal and school-based. Evidence on the effects of SEL programs has been mixed in the literature. In addition, few studies on this topic have directly focused on low-income children who attended high-quality early childhood interventions such as Head Start.

This study examines whether SEL services are associated with children's outcomes in third grade using data from a longitudinal follow-up study of children (n = 414) originally enrolled in a clustered randomized controlled trial (RCT) when they were in Head Start in disadvantaged neighborhoods in Chicago. Illinois was the first state that passed legislation in 2003 to require every school district develop a plan for implementing SEL programs and incorporate SEL skills as part of student learning standard. All children in third grade survey lived in Chicago or other areas in Illinois. Six types of SEL activities were reported by teachers and used as a rough proxy for children's greater versus lower exposure to SEL curricula in their schools, including classroom management, violence prevention, social-emotional development, character education, tolerance/diversity, and risk prevention.

This study takes advantage of pairwise matching in the RCT design to compare children who attended similar Head Start programs at baseline but received different doses of SEL services in third grade. Three-level hierarchical linear modeling (HLM) is conducted to account for clustering in the RCT design wherein children were nested within classrooms that were nested in Head Start sites. To capture the associations between SEL services and children's outcomes across these multiple developmental domains, we adopt several sets of measures widely used in large-scale surveys and small clinical trials. These measures include social-emotional (i.e., social skills, child-teacher relationship, and impulsiveness) and academic outcomes (i.e., language, literacy and mathematic skills).

We find that SEL services are associated with improvement of children's social-emotional and cognitive skills in third grade. The weekly/daily use of one additional type (out of six types) of SEL activities is associated with increased social skills (effect size 0.06-0.11), student-teacher relationship quality (effect size 0.12-0.16), and cognitive skills (effect size 0.06), and reduced impulsiveness (effect size -0.09 to -0.06). In other words, if children receive the average 3 types of SEL activities, the effect sizes would be 0.18-0.48 on social-emotional and cognitive skills and -0.18 to -0.27 on impulsiveness. These results are consistent with the findings from recent meta-analyses and randomized evaluations of individual SEL programs.

The findings can provide important implications for policymakers and help them make decisions on allocating scarce public funds to continuing enrichment programs such as SEL services, especially for low-income children.