One of major themes of the “Did Man Create God?” book is that much of what we are, including our capacity for spirituality, is determined by our genes and by our biological make up. Thus, in addition to discussing new relevant findings about evolution, in this blog I will also be reviewing new findings on the biology and genetics of human behavior, especially good versus evil – the control of which is generally believed to be within the domain of religious instruction.
    Over the many years I spent taking care of children with Tourette Syndrome and Attention Deficit Hyperactivity Disorder (ADHD), one of the major presenting problems was the presence of oppositional defiant disorder (ODD) - in short, constant talking back and nerdy acting out. Ever since the advent of Freud, such behavior was blamed on poor parenting. The stress of the resultant finger pointing often led to divorce. One of the exciting aspects of working with Tourette syndrome, a disorder universally recognized as being primarily genetic, was the finding that it was a spectrum disorder, meaning that in addition to the tics, ADHD, obsessive compulsive behavior (OCD), ODD, conduct disorder, depression, and many other behavioral problems were present. These were commonly assumed to be due to problems with early childhood environment and laid at the feet of the parents. Being associated with a genetic disorder, Tourette syndrome, indicated that in reality they all had a strong genetic component.
    I was intrigued by a recent report 1 that examined the neurobiology of angry teens. Sara Whittle and her colleagues had 137 teenagers and their parents participate in interactive sessions to evaluate levels of angry, aggressive, belligerent, and argumentative conflict. The teens were then examined with a MRI to examine different aspects of brain structure. As described in Chapters 28 and 30, the amygdala is part of the temporal lobe and the limbic system and regulates emotion, especially anger. The authors found that the children who exhibited the most prolonged aggressive and angry  responses to conflict had larger amygdala volumes. Variations in the size and symmetry of two other structures, the anterior cingulate and the orbital frontal cortex (see chapters 26 and 28) were also involved.
     Since twin studies have shown that the behaviors in question have a strong genetic component the changes observed in brain structure were likely to have been caused by a variant set of genes. These behaviors are common in children with conduct disorder, fifty percent of whom develop antisocial personality as adults. These studies provide one more piece of evidence showing that parents usually are not to blame for oppositional defiant behavior of their children – genes and neurobiology are. Skillful parenting, good environment and strong religious beliefs can help to moderate it, but  the absence of these things is not its cause.

1 Prefrontal and amygdala volumes are related to adolescent’s affective behaviors during parent-adolescent interactions. Whittle, S. et al. Proc. Nat. Acad. Sciences 105:3652-7, 2008