Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!

Evil on the Brain

PS2007's picture

Evil on the Brain

        Antisocial personality disorder is a mental disorder defined by the American Psychiatric Association's Diagnostic and Statistical Manual as, “A pervasive pattern of disregard for, and violation of, the rights of others that begins in childhood or early adolescence and continues into adulthood." People with this disorder are usually manipulative, selfish, and lack the ability to emotionally connect with others. Other people may experience them as charming and sociable, but they often put on this type of persona to exploit others (3). According to The National Comorbidity Survey, 3% of all people diagnosed with the disorder are male and 1% of them are female. The survey also found that in penitentiaries, the estimated percentage of inmates with antisocial personality disorder is 75% (1).

        The cause of antisocial personality largely remains unknown but this disorder is caused by a combination of environmental, hereditary and biological factors. Environmental patterns may include constant family conflict or lack of supervision as a child (2). Maternal deprivation during early life is often cited as a factor (1). They may also include alcohol and drug abuse, a lack of adult role models, and child abuse. Many psychologists believe that these children come to view the world as a dangerous place, with no rewards for following the law and act out a result (2).

        Recently, researchers have begun looking at biological causes for this disorder. Studies have shown that abnormalities in development of the nervous system may cause antisocial personality disorder. Another study indicates that if mothers smoked during pregnancy their children may be at risk of developing this disorder, because smoking lowers the amount of oxygen to the fetus that can result in brain injury. Other theories include the idea that people with antisocial personality disorder need greater levels of sensory input for normal brain function. This means that they may seek out dangerous situations to increase their arousal. Brain imaging studies have suggested that abnormal brain function is the cause of this disorder (4). Researchers at the National Institute of Mental Health's Unit on Affective Cognitive Neuroscience, believes that a dysfunctional amygdala affects the frontal cortex. They believe that the amygdala sends the wrong signals to the frontal cortex resulting in abnormal behavior (5). Adoption studies support the idea of both hereditary and environmental roles of the disorder. Twin studies support the idea of a genetic cause (1).

        More and more we are finding evidence that there are underlying neurological and biological factors that contribute to the development of mental illness. Instead of looking at outside influences and trying to find a cause, we are instead examining a person’s insides. The long-term effects of this new approach cannot be known at this time, but already I see a pattern emerging; we are examining the idea of choice. If a person is hardwired to act in a specific way, how can we punish them for doing so? While doing research for this paper, I was struck by the statistic that 75% of jailed criminals today are diagnosed with antisocial personality disorder. I was not shocked by this statistic because it did not make sense; I was more stunned by how much sense it did make given the behaviors associated with the disorder. How do we decide when someone is able to control their behavior and when they are not? How is antisocial personality disorder different from other mental illnesses? At this point we know very little about the causative factors of the disorder. Do we know enough to say that there is no treatment just because psychotherapy and medication is not usually effective (2)?

        The more I learn about neurobiology and behavior, the less certain I am about how much control we have over our own actions. Even if the cause of antisocial personality disorder is solely environmental, once we establish brain-behavioral patterns it is a struggle to act differently especially if we have never known any other way. I am not advocating for the release of all prisoners with this disorder. I just think that in light of all the new understanding there is about the connection between neurobiology and behavior we need to reassess old beliefs about behavior and make sure they are still valid. I hope in the future there is a lot more research on this subject.

Works Cited



Paul Grobstein's picture

brain and criminality

"in light of all the new understanding there is about the connection between neurobiology and behavior we need to reassess old beliefs about behavior"

I agree, and agree too that one of the issues needing clarification is the role in behavior of not only genes and environment but personal choice. Maybe not everyone has the same likelihood of exhibiting "criminal" behaviors in a given environmental context? Maybe not everyone has the same opportunities/capablilites for "choice"? How can we facilitate choice? Perhaps by recognizing that people are at the outset different from one another and need different things?