Genes shown to influence criminal behavior

Posted by Emma Woollacott

Genes could be a strong predictor of whether a person becomes a career criminal, according to US scientists.

The researchers based based their research on the theory that people fall into three types: life-course persistent offenders, adolescent-limited offenders, who grow out of their bad behavior and law-abiding abstainers. Dr Terri Moffitt, the author of the theory, suggested that genetics could be an influencing factor.

"That was the motivation for this paper. No one had actually considered the possibility that genetic factors could be a strong predictor of which path you end up on," says Dr JC Barnes, of the University of Texas, Dallas.

"In [Moffitt's] theory, she seems to highlight and suggest that genetic factors will play a larger role for the life-course persistent offender pathway as compared to the adolescence-limited pathway."

Adolescent-limited offenders exhibit behaviors such as alcohol and drug
Barnes and his team examined data from 4,000 people drawn from the National Longitudinal Study of Adolescent Health to identify how people fell into each of the three groups.

They then compared the information using twin methodology, to establish to what extent genetic and environmental factors influenced a trait.

"The overarching conclusions were that genetic influences in life-course persistent offending were larger than environmental influences," he said. "For abstainers, it was roughly an equal split: genetic factors played a large role and so too did the environment. For adolescent-limited offenders, the environment appeared to be most important."

The analysis doesn't identify the specific genes that underlie the different pathways, though, so you're unlikely to get banged up on the basis of a DNA test just yet.

"If we're showing that genes have an overwhelming influence on who gets put onto the life-course persistent pathway, then that would suggest we need to know which genes are involved and at the same time, how they're interacting with the environment so we can tailor interventions," he said.

Predicting criminality is a notoriously sensitive subject. The Department of Homeland Security was recently slated by privacy groups for testing a Minority Report-style system that monitored physiological measurements and used them to diagnose 'malintent'.

Using a person's genes to do the same thing would be even more controversial.

"Honestly, I hope people when they read this, take issue and start to debate it and raise criticisms because that means people are considering it and people are thinking about it," says Barnes.