Genes influence male teens’ attraction to delinquent peers

Male teens from high-risk families are significantly more likely to “hang out” with delinquent peers if the teens carry a particular variant of a gene affecting dopamine function, a new study reports. Association with delinquent peers is one of the strongest predictors of crime and delinquency.

Interested in whether adolescents’ genetic makeup influences their likelihood of joining an antisocial peer group, Kevin Beaver and colleagues focused in particular on the dopamine transporter gene (DAT1), a gene that has several variants. One variant, the 10-repeat allele, is associated with a range of pathology including gambling problems, depression, anxiety, attention deficit hyperactivity disorder, and childhood externalizing behavior problems.

The researchers evaluated data collected at three different stages from 1,816 teens participating in a long-range study of adolescent health. To assess the teens’ association with delinquent peers, they analyzed data on how often the teens associated with others who smoked, drank alcohol, and smoked marijuana (three behaviors highly correlated with delinquency).

For males from low-risk families, the researchers say, age was the only statistically significant predictor of association with delinquent peers. In males from high-risk families, however, the 10-repeat DAT1 variant was significantly related to having a delinquent peer group. Beaver and colleagues theorize that the low-risk teens’ parents were able to mitigate the effects of the DAT1 variant or, alternately, that the gene’s effects may be triggered by stressful environments.

The researchers say their findings reinforce those of Avshalom Caspi and colleagues, who reported in 2002 that people abused as children were highly likely to become antisocial adults only if they carried a specific variant of a gene affecting monoamine oxidase A (MAOA) function (see related article, Crime Times, 2002, Vol. 8, No. 4, Page 1). In the absence of an abusive environment, the MAOA variant did not significantly influence adult antisocial behavior. Both Caspi’s study and theirs, the authors say, reveal “the close interplay between genetic influences and environmental forces.”