Delinquent Behavior: Systematic Review of Genetic and Environmental Risk Factors

Delinquency refers to a juveniles' behavior pattern characterized by repeated offending, and is regarded mainly in its social, but also criminal aspects. Delinquent and non-delinquent individuals may be a product of the same society or even the same family. Young individuals who are unable to find affection and protection within the family may become more susceptible to delinquency as a form of empowerment. More than socioeconomic conditions, the lack of interaction between parents and children, the existence of psychopathological problems in either parent, and academic problems, together with a biological vulnerability, may be deciding factors for the involvement of young individuals in delinquent behavior. This review aims to analyze the influence of environmental and genetic factors in the development of delinquent behavior. Studies related to the influence of the environment and genes on the development of delinquent behavior were obtained from multiple databases, through rigorous exclusion and inclusion criteria. Of the 152 documents retrieved, 87 were retained for further analysis, and 36 final studies were considered eligible for inclusion. In addition to these, ten studies were added trough manual search, with the final sample thus comprising 46 articles, published between 1983 and 2016. Objectives, methodological aspects (samples and instruments), and main conclusions were extracted from each study. Overall, the interaction between genetic and environmental factors appears to best explain the variation of delinquent behavior. Environmental risk factors may have differential effects on the behavior of individuals, particularly according to their genetic propensity for delinquency.