<p>BCEagle makes a good point that there are often organic correlates for some of these personality/conduct problems… As well, there likely are environmental correlates, and early environment (physical and emotional, including in utero) also lead to changes in how a person’s brain functions and develops, so the physiological and the social influences are intertwined in early childhood. Causality is complex, multifaceted… It would be interesting to know what percent of the variance is accounted for by any one or even all of these risk factors, controlling for overlap among the factors. Often times, in human behavior, even consistent correlates only account for a small amount. Much as we want to understand, we are still left with the mysterious and unfathomable…</p>