Study reveals specific gene in adolescent men with delinquent peers

Oct 01, 2008

Birds of a feather flock together, according to the old adage, and adolescent males who possess a certain type of variation in a specific gene are more likely to flock to delinquent peers, according to a landmark study led by Florida State University criminologist Kevin M. Beaver.

"This research is groundbreaking because it shows that the propensity in some adolescents to affiliate with delinquent peers is tied up in the genome," said Beaver, an assistant professor in the FSU College of Criminology and Criminal Justice.

Criminological research has long linked antisocial, drug-using and criminal behavior to delinquent peers -- in fact, belonging to such a peer group is one of the strongest correlates to both youthful and adult crime. But the study led by Beaver is the first to establish a statistically significant association between an affinity for antisocial peer groups and a particular variation (called the 10-repeat allele) of the dopamine transporter gene (DAT1).

However, the study's analysis of family, peer and DNA data from 1,816 boys in middle and high school found that the association between DAT1 and delinquent peer affiliation applied primarily for those who had both the 10-repeat allele and a high-risk family environment (one marked by a disengaged mother and an absence of maternal affection).

In contrast, adolescent males with the very same gene variation who lived in low-risk families (those with high levels of maternal engagement and warmth) showed no statistically relevant affinity for antisocial friends.

"Our research has confirmed the importance of not only the genome but also the environment," Beaver said. "With a sample comprised of 1,816 individuals, more than usual for a genetic study, we were able to document a clear link between DAT1 and delinquent peers for adolescents raised in high-risk families while finding little or no such link in those from low-risk families. As a result, we now have genuine empirical evidence that the social and family environment in an adolescent's life can either exacerbate or blunt genetic effects."

Beaver and research colleagues John Paul Wright, an associate professor and senior research fellow at the University of Cincinnati, and Matt DeLisi, an associate professor of sociology at Iowa State University, have described their novel findings in the paper "Delinquent Peer Group Formation: Evidence of a Gene X Environment Correlation," which appears in the September 2008 issue of the Journal of Genetic Psychology.

The biosocial data analyzed by Beaver and his two co-authors derived from "Add Health," an ongoing project focused on adolescent health that is administered by the University of North Carolina-Chapel Hill and funded largely by the National Institute of Child Health and Human Development. Since the program began in 1994, a total of nearly 2,800 nationally representative male and female adolescents have been genotyped and interviewed.

"We can only hypothesize why we saw the effect of DAT1 only in male adolescents from high-risk families," said Beaver, who will continue his research into the close relationship between genotype and environmental factors -- a phenomenon known in the field of behavioral genetics as the "gene X environment correlation."

"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."

Among female adolescents who carry the 10-repeat allele, Beaver and his colleagues found no statistically significant affinity for antisocial peers, regardless of whether the girls lived in a high-risk or low-risk family environment.

Source: Florida State University

Explore further: US charges safari owners with illegal rhino hunts

add to favorites email to friend print save as pdf

Related Stories

Low grades in adolescence linked to dopamine genes

Sep 02, 2010

(PhysOrg.com) -- The academic performance of adolescents will suffer in at least one of four key subjects -- English, math, science, history -- if their DNA contains one or more of three specific dopamine ...

Recommended for you

US charges safari owners with illegal rhino hunts

49 minutes ago

Two South African men were charged Thursday by the US government with conspiracy to sell illegal rhinoceros hunts to American hunters, money laundering and secretly trafficking in rhino horns.

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

Bbrhuft
2.5 / 5 (2) Oct 01, 2008
This research agrees with a hypothesis I formed a while back. I noted the controversial claim that males raised without a father, are more liekly to offend and be involved in a gang.

I thus hypothesized that the absence of fathers and ensuing family stress maybe similar to a tribe that suddenly looses many adult males due to a tribal conflict. Accordingly, I predicted that the tribes male children in particular, would compensate for the tribes venerability by becoming more aggressive and likely to form defensive groups.

This intriguing research seems to confirm that there is an environmental mechanism that increases group affiliation by altering genetic expression, and it is interesting to note this only affects males. It seems to fit.
superhuman
not rated yet Oct 01, 2008
Keep in mind that males raised without a father in many cases don't have a father cause he was jailed, killed or left the family, all this cases imply an antisocial behavior or at least lack of empathy. That means that similar problems of their sons can be simply explained by inheritance.

It would fit with the story if the 10-repeat allele was responsible for limited empathy in males or some other predisposing change (like thrill seeking, lowered sense of responsibility, lack of strong morals, egocentric behavior, etc).

Those in no risk families might have more opportunities, for example better education which allows them to choose paths not available for members of high-risk families.
Bbrhuft
not rated yet Oct 02, 2008
I disagree, this appears to be an epigenetic effect. Indeed, there is growing interest in epigenetics and antisocial behavior,

Towards an epigenetic approach to experimental criminology: The 2004 Joan McCord Prize Lecture. RE Tremblay - Journal of Experimental Criminology, 2005

Epigenetic effects of child abuse and neglect propagate human cruelty. JE Swain, Behavioral and Brain Sciences, 2006

Epigenetic inheritance and the intergenerational transfer of experience. LV Harper, Psychological Bulletin, 2005

PREVENTION OF CHRONIC PHYSICAL AGGRESSION: AN EPIGENETIC PERSPECTIVE. RE Tremblay - Crime And Schizophrenia: Causes And Cures, 2005
superhuman
not rated yet Oct 03, 2008
The article focuses on *genetic* effect - 10-repeat allele which correlates with having delinquent peers (since genetic code is different in their case it is genetic not epigenetic effect).

Epigenetic effect (sort of) is only mentioned in the end in the speculation why the effect is only present high-risk families.

There is a growing interest in epigenetics in general due to new tools becoming available which make such research possible, but I don't see how it is relevant here.
Velanarris
not rated yet Oct 04, 2008
The article focuses on *genetic* effect - 10-repeat allele which correlates with having delinquent peers (since genetic code is different in their case it is genetic not epigenetic effect).

Epigenetic effect (sort of) is only mentioned in the end in the speculation why the effect is only present high-risk families.

There is a growing interest in epigenetics in general due to new tools becoming available which make such research possible, but I don't see how it is relevant here.


Yes but through natural selection a genetic effect can arise from a past epigenetic cause. So you're really both talking about the same thing, jsut at different points in time.

Past tribal warfare wiping out generations of males would lead to an environment where it's conducive to passing on your genes if you're more socially adept and violent.