- FRIDAY, Oct. 10 (HealthDay News) — Adolescent boys with a certain
genetic makeup are more likely to have delinquent peers, researchers
say.

Being antisocial, using drugs, and criminal behavior is known to be
linked to having delinquent peers. And belonging to a delinquent peer
group is one of the strongest predictors of criminal behavior.

A study published in the September issue of the Journal of Genetic
Psychology looked at the genetic makeup of 1,816 boys in middle and
high school.

The researchers found that the boys who had a particular variation —
the 10-repeat allele — in the dopamine transporter gene (DAT1) were more
likely to be affiliated with delinquent peers. However, the gene variation
only affected the risk of having delinquent peers in a certain
environment.

In boys who were from a high-risk family environment, marked by a
disengaged mother and absence of maternal affection, the DAT1 variant was
associated with having delinquent peers. But in those who lived in
low-risk families (those with high maternal engagement and warmth), the
DAT1 variant was not statistically associated with having antisocial
peers.

“Our research has confirmed the importance of not only the genome, but
also the environment,” Kevin M. Beaver, a criminologist at Florida State
University, said in a school news release.

Beaver said that he and his colleagues can only hypothesize why the
variant just affected the boys from high-risk families.

“Perhaps the 10-repeat allele is triggered by constant stress or the
general lack of support, whereas in low-risk households, the variation
might remain inactive,” he said. “Or it's possible that the 10-repeat
allele increases an adolescent boy's attraction to delinquent peers
regardless of family type, but parents from low-risk families are simply
better able to monitor and control such genetic tendencies.”

The 10-repeat allele was not associated with an affinity for antisocial
peers among adolescent girls, whether the girls lived in a high-risk or
low-risk environment.

More information

The U.S. Centers for Disease Control and Prevention has more about the gene-environment interaction.