Affect heuristics and peer effect on substance use among adolescents in Brazil

Significant changes are observed during adolescence with respect to health-related habits and risky behaviors. Among the behavioral changes, the consumption of substances such as alcoholic beverages, cigarettes, and illicit drugs, and social interactions are relevant factors for the intake of such substances. This study aims to analyze the relationship between the joint decisions of substance use by adolescents and their peers from the perspective of the affect heuristics. To this end, a multivariate probit model was estimated, based on microdata from the 2019 National School Health Survey. The results showed that substance use by adolescents was positively related to substance use by their peers; therefore, having friends who consume alcohol, illicit drugs, and cigarettes or having parents who consume alcohol or cigarettes increases the likelihood of an adolescent consuming these substances. The study also identified that the substance consumption decision was governed by an unobserved common factor compatible with the affect heuristic.