A Case of Nurture over Nature

Jake Meyer by Jake Meyer

Neuroscientist James Fallon has been studying behavioral disorders for 20 years at the University of California at Irvine, but he made his biggest discovery in his own backyard.  At a family barbeque, James's 88 year-old mother recommended to him that he find out about his father’s relatives, saying "I think there were some cuckoos back there."  What he found was a 300-year family history that included eight convicted and alleged murderers.  Among his ancestors are a man who was sentenced to death by hanging for murder in 1667 and the infamous Lizzy Borden.  Fallon was understandably concerned.  As part of a family study to determine risk of Alzheimer’s disease, he had already convinced 10 of his family members and relatives to take a brain scan and give a blood sample.  After years of studying the criminal brain, Fallon knew the signs associated with behavioral disorders, so he compared the brain scans.  Only one of the family brain scans showed the pattern of what he calls a psychopath – his own. 

In his career, Fallon has studied the genetics and brain activity of criminals – including convicted and alleged killers – for clues into psychiatric disorders.  He uses the term psychopath to generally describe the killers he has studied, but the World Health Organization (WHO) includes psychopathy as one type of Dissocial (Antisocial) Personality Disorder – a "personality disorder, usually coming to attention because of a gross disparity between behavior and the prevailing social norms."  Fallon’s research has led him to three ingredients he believes are present in the genetic and behavioral make-up of psychopaths: (1) abnormal genetics, (2) distorted brain function, and (3) early childhood abuse.  First, there are 12 genes generally associated with violent behavior, including monoamine oxidase A (MAO-A, or the "warrior gene").  Researchers believe that certain copies of the MAO-A gene reduce the ability of the human brain to respond to serotonin, a hormone that affects mood.  Second, psychopaths show decreased frontal lobe activity, the area that codes for ethics, morality, and conscience, but also controls impulse.  The third ingredient, early childhood abuse, is the ingredient under the control of external influences.  Fallon found he has two of the three ingredients – the "warrior gene" and the brain activity of a killer – but he credits loving family relationships with helping him develop into a gentle, kind husband and father. 

James Fallon does, however, question the existence of free will in patients with certain behavioral disorders who have all three of his ingredients.  Fallon compares the urge to kill in a psychopath to the urge to go to the bathroom in a normal individual.  While the psychopath can try to put it off, the urge cannot be completely suppressed.  Manipulation can be masked under the guise of self-control.  Fallon admits he does exhibit some characteristics of habitual criminals: he is a risk-taker, a bon vivant, and he hates to lose at Scrabble. James Fallon did, however, also have a wonderful childhood that he believes protected him from biology. 

Fallon’s research and personal life story illustrate the problem of relying solely on genetics to indicate behavioral traits.  A society might use the MAO-A gene, for example, to screen for potential criminals.  Those found with the gene might be placed under surveillance, or even incarcerated in an effort to stop a would-be killer.  Or, perhaps, a genetic test indicating the MAO-A gene might be used as evidence in sentencing as mitigating factor in a murder trial because the person was predisposed to kill.  Fallon's research demonstrates the problem inherent with behavioral genetics.  When looking only at Fallon's genetic make-up and brain scan, one might mistakenly see a violent killer waiting to explode, and not the accomplished neuroscientist and loving family man he really is.