Enlisting Peer Cooperation and Prosociality in the Service of Substance Use Prevention in Middle School

A key contributing factor to the initiation and escalation of substance use during early adolescence is affiliation with deviant peers. These affiliations often arise when socially isolated and rejected youth aggregate and reinforce substance use and other deviant activity within the group (i.e., "deviant peer clustering"). Even though the field has developed a number of efficacious prevention programs, few have demonstrated strong effects on deviant peer clustering. Further, on a national level, substance use among adolescents continues to be high, suggesting that a fresh approach to prevention with a renewed focus on the peer context is needed to create a broad, sustainable public health impact.

Existing programs have proven difficult to disseminate with fidelity, often due to their complex design or the significant expenditures required for curricula, materials, and training. To realize broader public health benefits, an approach that integrates scientific knowledge across domains must be applied to develop and test programs that address root causes of youth substance use, are less complex and expensive to implement, are more flexible and adaptable to local conditions, and once established, can spread.

This proposal represents an approach to prevention in which evolutionary theory provides a unifying theoretical framework, which implies that diverse problems are due to social environments that are unfavorable for the expression of prosocial behaviors, instead eliciting a variety of self-oriented or exploitative behaviors. Systematic efforts to reduce multiple problems among youth (e.g., substance use, risky sex, depression, academic failure, etc.) need to look beyond the immediate issues to the social conditions that make the entire range of problems more likely. Programs should focus on modifying key social environments to nurture prosocial behavior and minimize the toxic or stressful conditions that give rise to behavioral problems in youth.

The investigators propose to integrate a few simple, flexible, and powerful prevention strategies that have proven value in establishing a social context conducive to positive peer group development. This project will apply cooperative learning and behavioral kernels to reduce social rejection and isolation, promote new friendships among youth from different social groups, and encourage greater levels of prosocial behavior. This should create a positive feedback loop in which the social and behavioral processes "amplify" one another to bring significant change to the school social context, interrupting deviant peer clustering and addressing a key root cause of escalations in substance use and related problem behavior. With this approach, the investigators anticipate a simple, straightforward implementation, greater sustainability, and opportunities for the program to spread through sharing of best practices among teachers. This project will conduct a small-scale randomized controlled trial involving 12 middle schools in the state of Oregon.

Aim 1a of the project is to evaluate the main effects of the program on both prosocial behavior and substance use. The investigators will also examine effects on secondary outcomes, including delinquent and high-risk sexual behavior, teasing and harassment, depression, school attendance, and academic achievement. The project will include an assessment of program fidelity, which will be incorporated into data analyses. Aim 1b of the project is to explore links among peer rejection, prosocial behavior, and substance use over time in an attempt to determine the direction of effects, which can inform both developmental theory and future intervention design.