Over the past two decades, there's been growing interest in protective factors against social, emotional, and behavioral problems in compulsory education. Social and Emotional Learning (SEL) stands out as a key protective factor, encompassing the acquisition and effective use of knowledge, skills, and attitudes necessary for healthy identities, emotional management, goal setting, empathy, positive relationships, constructive conflict resolution, and responsible decision-making. This study focuses on assessing the effectiveness of an SEL program designed to improve social and emotional competencies among Basic VET pupils from disadvantaged backgrounds in Spain. SEL integrates behavior, cognition, and affect, equipping learners with tools to navigate daily life, improving learning, performance, and satisfaction. While existing research shows positive correlations between SEL interventions and improvements in socio-emotional, behavioral, and academic outcomes across diverse populations, much of this evidence comes from Anglo-Saxon contexts. Studies in Ibero-American contexts often lack the methodological rigor to establish causal relationships due to limitations in evaluation measures, research designs, and sample sizes. This study aims to address these gaps by employing a robust quasi-experimental design to evaluate a comprehensive SEL program implemented within the context of Basic VET, which has high dropout rates, particularly impacting students from disadvantaged backgrounds. The program integrates school instruction with explicit SEL skill training, active learning methodologies, clear goals, and collaboration among students, families, and communities. The research hypotheses posit that the experimental group will show statistically significant improvement in SEL competencies compared to the control group.

Numerous studies have established causal relationships between SEL interventions and improvements at socioemotional, behavioral, and school levels, regardless of students' socio-demographic profiles. Meta-analytic reviews consistently show that SEL interventions improve social and emotional skills, self-perceptions, attitudes, school engagement, prosocial behavior, and academic performance, while decreasing emotional and behavioral difficulties. However, most of this research originates from Anglo-Saxon contexts. A systematic review of SEL programs in Ibero-American contexts revealed relatively low-quality evidence for establishing causal relationships, mainly due to shortcomings in indicator selection, evaluation measures, research design, sample sizes, and intergroup comparability. This highlights the need for higher-quality research in Ibero-American contexts to support national agendas for SEL adoption.

This quasi-experimental study used a non-equivalent control group design with statistical control techniques. The sample comprised 110 first-year Basic VET pupils (55 experimental, 55 control) from three programs at a Madrid educational center. Pupils were assigned to groups randomly at the classroom level, ensuring equivalence across observable characteristics (age, sex, socioeconomic status, etc.). The SEL program, implemented throughout the school year (September 2021–June 2022), involved explicit instruction of SEL competencies integrated into the VET curriculum. Active learning methodologies, transversal projects, service-learning, and meaningful experiences (e.g., workshops, field trips, internships) were used. Teacher training and program piloting occurred in the preceding year. The Social and Emotional Learning Scale (SEL Scale), a validated Likert-type scale assessing five SEL competencies (self-awareness, social awareness, self-control, relationship skills, and responsible decision-making), was administered as pre- and post-tests. A Participation Questionnaire collected socio-demographic and educational data. Data analysis included power analysis, checks for linearity and normality, descriptive statistics, Mann-Whitney U tests (for intergroup comparisons), and Wilcoxon z tests (for intragroup comparisons). Effect sizes (Cohen's d) were calculated, and Bonferroni correction controlled for family-wise error rate.

Initial analysis confirmed no atypical cases or violations of assumptions. Pre- and post-test comparisons revealed no significant changes in the control group. The experimental group showed statistically significant improvements in all five SEL competencies from pre-test to post-test (Table 3). Intergroup comparisons (Table 4) showed no significant differences at pre-test but significant differences in favor of the experimental group in all five SEL competencies at post-test. Effect sizes were medium to large (0.5–1.25), indicating a substantial impact of the program. The results held even under the stringent Bonferroni correction. The practical significance of the findings, evaluated using effect size interpretations (Hattie, 2009; Kraft, 2020), showed large effect sizes, meaning the intergroup differences were easily observable and of significant practical relevance. Effect sizes revealed that a hypothetical member of the experimental group scored above 69% (relationship skills) and up to 88% (self-awareness) higher than a member of the control group in certain SEL competency areas.

The findings strongly support the efficacy of the SEL program in enhancing the social and emotional competencies of at-risk Basic VET pupils. The statistically significant and practically relevant improvements across all five SEL competency areas demonstrate the program's positive impact on pupils' social-emotional development. These results align with previous meta-analytic reviews showing positive effects of SEL interventions. The study's rigorous methodology strengthens the causal inference regarding the program's effectiveness, particularly valuable considering the limited high-quality research on SEL interventions in the Ibero-American context. The results underscore the importance of implementing evidence-based SEL programs in educational settings, providing valuable data for developing national educational strategies.

This study provides strong evidence for the effectiveness of a comprehensive SEL program in improving the social and emotional competencies of at-risk Basic VET students. The large effect sizes observed across all five SEL competencies highlight the program’s practical significance and potential to positively impact students’ academic and life outcomes. Future research could explore the long-term effects of the program, expand the sample to include a wider range of VET programs, and investigate the program’s effectiveness in different cultural contexts. This program serves as an example of an evidence-based approach to promoting SEL, particularly valuable in addressing the needs of disadvantaged students within the VET system. The findings advocate for increased investment in and systematic evaluation of similar SEL interventions.

The study's limitations include the use of a convenience sample and a quasi-experimental design, which might limit the generalizability of the findings. While efforts were made to match the experimental and control groups on various observable characteristics, unobserved confounding variables may still exist. Future research with randomized controlled trials and larger, more diverse samples is recommended to enhance generalizability. Additionally, increasing the number of covariates could enhance the precision of causal inference. Finally, the study's focus on a specific educational context and program might limit the direct applicability of the findings to other settings.