facilities from April to mid-October of the 2016 academic year. The study sample includes 1,056 enrolled students aged 10 to 16 years old.<sup>9</sup> This age range is relevant in the Salvadoran context because that is when children and adolescents are likely to be recruited by gangs.

All randomly selected participants attended two sessions per week that lasted 1.5 hours each. The intervention was implemented by volunteers of the Salvadoran branch of Glasswing International, a nongovernmental organization (NGO) working in Central America and Mexico. Every session is a combination of: (1) a discussion oriented toward fostering children’s conflict management, violence awareness, and social skills; and (2) the implementation of curricula including activities such as scientific experiments, artistic performances, and others.

In the first part, instructors discuss concrete methods for regulating participants’ violent behavior using experiential learning or role-playing. This allows participants to take action in their lives, face difficulties, and learn how to solve problems proactively. To apply this therapy in the ASP, a tutor implements an experiential learning activity in which she mentions day-to-day difficulties that children typically face in low-income contexts. She asks them to brainstorm solutions to those problems and evaluate them. The second part of the session includes the implementation of ludic activities related to each club category. This section aims to motivate students to participate in the intervention and increase ASP attendance.

To measure the program’s overall impact and exploit excess demand, we rely on the first stage of Dinarte (2018)’s experimental setting. We randomly granted some of the enrolled students participation in the intervention while the remaining students were assigned to a comparison group. Before the intervention, we collected self-reported data on personal and family characteristics from enrolled students. Follow-up self-reported data included questions to measure the intervention’s impact on attitudes, violence, and crime; exposure to risky spaces; and educational or personal expectations. We combined this self-reported information with administrative records on math, reading, and science grades; behavioral reports; and absenteeism data from both enrolled and nonenrolled students. Schools provided these data before and after the intervention.

Additionally, we collected neurophysiological evidence from a random subsample of enrolled students at the end of the intervention. By using the James-Lange theory of valence and arousal (Davidson et al., 1990; Harmon-Jones et al., 2010; Ramirez and Vamvakousis, 2012; Verma and Tiwary, 2014), and following the methodology developed by Egana-delSol (2016b), we proxied participants’ emotional regulation and stress directly from their brain activity. We used portable

> 9As we explain in detail later, there are two samples in this study. The first one is enrolled students—those who decided to participate in the ASP and were randomly assigned to treatment or control groups (1,056 students). The second sample of nonenrolled students includes those who were not registered for the ASP but were in the same schools and classrooms as treated students (1,364 students).

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