Our research suggests that the combination of hardwired neurological factors and a bad childhood and adolescence contributes most often to an antisocial personality. It is possible that without one or the other influence, the violence-prone predator never emerges, as suggested by our informal control group of law-abiding siblings like David and Mikal. But this is not a laboratory experiment where we can play it out two ways. At this point in the development of both neuropsychology and criminology, the best we can offer is theories.
