01/26/2012 04:36 pm ET Updated Mar 27, 2012

Genes, Criminal Behavior Linked In University Of Texas Study

What turns people into criminals? In the longstanding debate over nature vs. nurture, new research published in the journal Criminology suggests that genes play a key role in determining who leads a life of crime and who stays on the straight and narrow.

The research, conducted by University of Texas at Dallas criminologist J.C. Barnes and colleagues, analyzed the genetic and environmental influences on criminal traits of 4,000 people. The researchers discovered a strong link between genes and criminality.

The scientists based their research on the 1993 theory of Duke professor Dr. Terrie Moffitt that says people will generally fall into three different types: life-course persistent offenders (lifelong criminals), adolescent-limited offenders (who grow out of their bad behavior), and law-abiding abstainers (non-criminals).

According to the paper:

  • For life-course persistent offenders, genes influenced criminal behavior more than the environment.
  • 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 was the most important factor.

"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," Dr. Barnes said.

But don't expect police to start locking people up based on their genomes anytime soon. Researchers say there is no single gene to predict criminality; there are likely to be hundreds, if not thousands of genes that will affect your likelihood of being involved in crime. And even then, it may only increase that likelihood by 1 percent.

But that doesn't mean the genetic link should be taken lightly, Barnes points out.

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