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Researchers studied over 440 New Zealand males with this gene abnormality, from birth to adulthood, to look for the biological basis of antisocial behaviour.85 They discovered that over eight out of ten males who had the MAOA gene abnormality went on to develop antisocial behaviours, but only if they had been raised in an environment in which they were maltreated as children. In contrast, only two out of ten males with the same abnormality developed antisocial adult behaviour if they had been raised in an environment with little maltreatment. This explains why not all victims of maltreatment go on to victimize others. It is the environment that appears to play a crucial role in triggering whether these individuals become antisocial.86 This is why it makes no sense to talk about nature and nurture as separate when we consider how our individuals develop.

Natural Born Killers

If early abuse turns on the effects of the warrior genes, can these negative attributes also be turned off? Neuroscientist Jim Fallon studies what makes psychopaths tick by looking at their brain activity and genes. One day, as he was sorting through lots of scans of psychopathic murderers, he noted that they all seemed to lack inactivity in the orbital cortex, a region of the prefrontal cortex. The orbital cortex is related to social behaviours such as smiling, and is also a region associated with moral decision-making and control of impulsive antisocial behaviour. People with low activity in this region tend to be free-wheeling types or psychopaths. Perhaps these psychopaths had bad brains?

At the time, Jim was also working on Alzheimer’s disease and needed control data to compare with patients. He persuaded members of his family to have their brains scanned and provide blood samples to match against the clinical sample. Every one of his relatives’ brain scans was normal – except one – his own. Jim discovered that he had the identical lack of activity in the orbital cortex that he had observed in the psychopathic killers. The irony of the neuroscientist discovering that he also had the same abnormal brain pattern as the killers was not lost on Jim.87

About a month later at a family barbecue, he was pointing this irony out to the other family members when his eighty-eight-year-old mother, Jenny, suggested that maybe he should do a little research into the family history, as he might be surprised. What Jim discovered was truly shocking. It turned out that his ancestor, Thomas Cornell, was infamous in American history as the killer of his own mother in 1667, the first documented case of matricide. But it didn’t stop there. There were another seven murderers in the line of the family from which Jim was directly descended! This was worrying. Jim looked for other evidence. Did he have the genes associated with aggression and violence? He had the blood taken from the Alzheimer study analysed. Jim’s blood was positive for the warrior gene and he had all the genetic risk factors that could predispose him to become a killer. At the time, geneticists likened the odds of Jim possessing this constellation of genes to walking into a casino and throwing double-six fifteen times in a row.

According to the biology, Jim should have been a natural born killer and a menace to society, but he wasn’t. Why not? Dr Jim Fallon used to be the type of scientist who followed a fairly genetic determinist line, believing that your genes pretty much determine your outcome, but his discoveries in brain imaging and genetics forced him to rethink his own rigid view of human nature. He had to accept that in his case the role of the environment had protected him, and in particular the nurturing from his own parents had played a major part in the way he turned out. This is because, from the very start, Jim was a special birth for his parents. His mother had four miscarriages in a row before Jim was finally born. It would be a long time before his mother had any more children and so Jim was treated as a precious child with a lot of attention and affection directed towards him. He believes all this nurturing offset the warrior gene that could have sent him off on a path of destruction.

Jim has avoided a life of crime and violence but recognizes that he still has many of the personality attributes of low orbital cortex activity. However, he recognizes that his own flaws may be residuals of his genetic predisposition. Rather than harming people, Jim simply does not make a strong emotional connection with others. He does not generally care about other people, especially those who are close to him, and he recognizes that he is close to the edge of being a psychopath.88 I expect that we all know someone like that.

Incubated in Terror

How does someone become a psychopath? Bruce Perry is a psychiatrist who believes that the origins of human violence can be traced to the environment in which we raise our children. If that environment is lacking in appropriate role models and examples of how to behave and treat others, then children fail to develop an appropriate moral dimension to their sense of self. Combine that with the stress of poverty and lack of education necessary to raise one’s self out of these conditions, and you have a recipe for disaster. Perry was called as an expert witness in several high-profile cases – the Columbine High School massacre, the Oklahoma City bombing and the Waco siege. He is a highly acclaimed and respected scientist who argues that human violence is a vicious cycle that begins early in development. To illustrate his case, Perry describes an example of a pointless teenage murder:

A fifteen year old boy sees some shoes he wants. Another child is wearing them – so he pulls out his gun and demands the shoes. The younger child, at gunpoint, takes off his shoes and gives them up. The fifteen year old puts the gun to the child’s head, smiles and pulls the trigger. When he was arrested, the officers are chilled by the apparent lack of remorse. Asked later whether he could turn back the clock and do anything differently, he thinks and replies, ‘I would have cleaned my shoes.’ His bloody shoes led to his arrest.89

Perry thinks such blindness to the plight of others is a form of retardation that results from a lack of appropriate emotional and social interaction as a child. This is an extreme case of Bowlby’s social isolation, in which the child has failed to develop a moral dimension to the sense of self. Like Bowlby, Perry argues that such retardation is a consequence of not exposing the child to appropriate experiences in which negative emotions are triggered but are then resolved. Without this experience, vulnerable children fail to lay down the models of appropriate behaviour during sensitive periods of social development.

According to Perry, this failure is due to the disruption of the development of neural circuitry that regulates behaviour. If you remember back to the organization of the functional structures of the brain, the lower brain systems are the origins for impulsive behaviour, including aggression. Perry argues that regulated behaviour depends on the relative strength of activation arising from the lower, more primitive portions of the brain and the modulating inhibitory action of higher cortical areas. Factors that increase the activity or reactivity of the brain stem, such as chronic stress and abuse, or that decrease the moderating capacity of the limbic or cortical areas, such as isolation and neglect, will increase an individual’s aggression, impulsivity and tendency to be violent. Only by raising children in nurturing environments can we provide the experiences within the right context that enable them to regulate their impulses and drives.

Examples of early violent behaviour are not rare. For instance, there has been a much-reported epidemic of fatal stabbings among teenagers in the United Kingdom over the past couple of years. However, the majority of children raised in impoverished backgrounds are not destined to become remorseless killers. According to Perry, they nevertheless carry the emotional scars. They tend to move through life in a series of destructive relationships, often with a profound sense of disconnection and emotional emptiness. This leads to the associated problems of addiction, crime and social poverty, thus establishing a destructive cycle for the next generation raised in this environment. Life loses its value and effectively becomes cheap, thus providing a fertile ground in which to breed a disregard for others. With over five million child victims of domestic violence in the United States alone and, worldwide, vast numbers of children impoverished by war and famine, Perry makes a convincing case that, despite our advances as a civilization, we are still raising children incubated in terror.