Here’s another key excerpt from Adrian Raine’s The Anatomy of Violence: The Biological Roots of Crime which explains why New Orleans and Birmingham are so plagued by “senseless violence” and “tragic shootings”:
Note: The prefrontal cortex is the part of the brain immediately behind the forehead. In normal people, the prefrontal cortex is lit up by glucose metabolism in red like in the image below, but in common criminals who engage in “senseless violence,” there is much less activity in this region of the brain.
1. At an emotional level, reduced prefrontal cortex functioning results in a loss of control over the evolutionary more primitive parts of the brain, such as the limbic system, that generate raw emotions like anger and rage. The more sophisticated prefrontal cortex keeps a lid on these limbic emotions. Take that lid off, and the emotions will boil over.
2. At a behavioral level, we know from research on neurological patients that damage to the prefrontal cortex results in risk taking, irresponsibility, and rule-breaking. It’s not too far to go from these behavioral changes to violent behavior.
3. At a personality level, frontal damage has been shown to result in a whole host of personality changes. These include impulsivity, loss of self-control, and inability to modify and inhibit behavior appropriately. Can you imagine these types of personality traits in violent offenders?
4. At a social level, prefrontal damage results in immaturity, lack of tact, and poor social judgment. From here we can imagine how a lack of social skills can result in socially inappropriate behavior and poorer ability to formulate nonaggressive solutions to fractious social encounters.
5. At a cognitive level, poor frontal functioning results in a loss of intellectual flexibility and poorer problem solving skills. These intellectual impairments can later result in school failure, unemployment, and economic deprivation, all factors that predispose someone to a criminal and violent way of life.
It’s not just one level of analysis but five – five reasons we might expect that poor prefrontal functioning could predispose a person to violent behavior. It’s not surprising, therefore, that poor prefrontal functioning is the best-replicated correlate of antisocial and violent behavior.
Raine goes on to explain that successful serial killers like Randy Kraft and Ted Bundy have excellent brain functioning in the prefrontal cortex. He distinguishes between “proactive aggressives” – cold blooded murderers who combine violence with forethought to advance their ends – and “reactive aggressives” – hot blooded low IQ types who are unable to control their volatile emotions.
In psychopaths, the amygdala, the emotional center of the brain which plays a key role in moral decision making, barely flickers in brain scans. This is why psychopaths are unable to empathize with others and feel guilt or remorse from their actions.