A new study might be inching us closer to the possibility that the worst criminals can blame their behavior on bad genes. In the study of 900 convicts in Finland, researchers found that those with mutated forms of two genes were 13 times more likely to have a history of violence, reports the BBC. The researchers said that up to 10% of violent crime in Finland can be attributed to people with this particular genetic profile. For the science-minded, the genes in question are monoamine oxidase A (MAOA), which is linked to dopamine levels in the brain, and cadherin 13 (CDH13), which is linked to impulse control, reports the Telegraph. Scientists from Sweden's Karolinska Institute emphasize that human behavior is unimaginably complex and that they are not suggesting screening for criminals.
“We’ve observed two genes that have a relatively big effect on violent behavior, but there are possibly tens or hundreds of other genes that have a smaller effect," says one. "This is why a ‘test for criminality’ is not possible from this study." A scientist not involved with the work echoes the sentiment, telling the Independent that "to call these 'genes for violence' would ... be a massive exaggeration." But the study in Molecular Psychiatry points the way for future research, raising the possibility of identifying people at risk early and trying to steer them away from trouble. For instance, the bad behavior associated with the MAOA gene may be more pronounced when booze or drugs is involved, reports io9. (Another study found that moms' stress in pregnancy shows up in their kids' DNA.)