IS CRIME GENETIC? Scientists don’t know because they’re afraid to ask. [archive]

The effects [archive] of genetic differences make some people more impulsive and shortsighted than others . . .

Most of the evidence about the causes of crime overlooks genetic transmission. Yet, some research [archive] has found that once you account for genetic influences on self-control, [archive] . . . the effect of parenting on self-control diminishes or goes away entirely. . . .

A remarkable study [archive] in Sweden recently found that highly disadvantaged neighborhoods had more crime. Yet that neighborhood effect disappeared when risk factors concentrated within certain families were taken into account. Once again, social transmission effects weakened (and, in this case disappeared) when other factors like genetic transmission were controlled for. Does this finding guarantee that similar results will emerge in other samples around the world? No. But criminologists rarely consider the possibility that their own studies could be polluted by hidden genetic effects.

The more technical term for this phenomenon is genetic confounding, and there is reason to believe that it is endemic to much of the research coming out of the social sciences in general, and criminology in particular. Our own research [archive] into the issue suggests that even a modest amount of unmeasured genetic influence can pollute and infect your findings. As a result, much of what we think we know about the causes of crime could be overstated or just flat wrong.