by Alana Duffy
Many of us have watched an episode or two of Criminal Minds and wondered to ourselves, “how can someone be so messed up? What could turn a normal human being into a heartless, psychopathic monster?” Most psychopaths in mainstream media have usually been through some sort of traumatic childhood event. However, most Law and Order type programming often ignores the nature side of the Nature vs. Nurture debate. Environment and life experiences are suggested to play a large role in the creation of a psychopath, but so do genetics and physical abnormalities of the brain.
Most of us experience varying degrees of stress at some point or another, and how we react to these events is partially regulated by a series of genetic predispositions. One explanation is the Diathesis-Stress model, which suggests that people inherit certain stress responses. The term ‘diathesis’ represents these genetically inherited tendencies. However, these behaviours don’t become prominent until a certain environmental trigger occurs. This suggests that someone could be a psychopath and not know it until they’ve been triggered by a certain stressful event. Exams aren’t typically a stressor involved in psychopathy, but I’d be lying if I said I’ve never made a joke about killing the person sitting across from me because they’ve been yelling on the phone for 45 minutes. More commonly, triggers amongst psychopaths include physical or emotional neglect, or general familial instability during childhood. But here’s the thing: not everyone who experiences one or more of these childhood stressors becomes a raging murderer. This illustrates that genes have a large role in our emotional reactions to a situation. Thankfully the particular genotype (MAOA-L) found in psychopaths seems to be relatively rare.
But what exactly is MAOA-L, and why is it important? This gene is a low-expression variant of the MAOA (Monoamine Oxidase A) gene that has been linked to an increased risk of violent and aggressive behaviour. Monoamine Oxidase A is an enzyme responsible for breaking down monoamine neurotransmitters such as dopamine and epinephrine (more commonly known as adrenaline). A mutation in the MAOA gene leads to a deficiency of Monoamine Oxidase A, which in turn causes an excess of monoamine transmitters. This contributes to the impulsive and violent behavior of psychopaths.
Additionally, genes regulate the physical development of our brains. The limbic system, an area of the brain involved in memory formation and emotional processing, is often underdeveloped in psychopaths. We gather new life experiences through our senses, and this sensory input travels to the hippocampus (our memory processing and storage centre) where it is consolidated and compared with our previous experiences. The amygdala, a structure involved in emotional responses, then decides how we should feel about the situation based on past events.
Considering this, it is unsurprising to learn that neuro-imaging studies show reduced blood flow (an indicator of brain activity) to the hippocampus and amygdala - psychopaths don’t process experiences the same way “normal” people do. Therefore, they don’t always have the proper emotional response to a situation. Essentially, they don’t make the necessary connections to learn from previous mistakes and thus don’t feel guilty about their actions.
Another area of interest in the psychopathic brain is the prefrontal cortex of the frontal lobe of the brain. The frontal lobe is responsible for motor function, problem solving, memory, language, judgement, social behavior, and a host of other things. In particular, the prefrontal cortex is in charge of forward planning, prediction of outcomes, expectation processing, and social control. Once the amygdala has processed memory experience and has decided on an appropriate (or highly irrational) emotional response, this idea travels to the prefrontal cortex, where it is then decided whether the action is actually a good idea. You probably know where I’m going with this. The prefrontal cortex is yet another area in the psychopathic brain that doesn’t work the way it’s supposed to. Lesions in this area are typically associated with uninhibited behavior, and in psychopaths there is an overall reduction in metabolism and activity here. The characteristic impulsiveness and lack of concern for consequences seen in psychopaths is largely due to prefrontal cortex dysfunction.
Remember the Stauffer Library example mentioned earlier, about someone talking loudly on the phone? Most of us are neurologically developed enough to know that murder is an irrational and immoral response to any situation. Additionally, the consequences are too great. Orange Is The New Black is a great show, but jail is still very unappealing. I don’t know about you, but personally all I ever do is give the person dirty looks, or maybe get annoyed enough to actually say something. However, a true psychopath may not make those connections. They process the world differently and cannot assign rational emotional responses to their experiences. They likely wouldn’t consider or care about the repercussions of their actions. So, the next time you complain to your friends about the “psycho” who keeps quadruple-texting you, take a moment to be thankful that you are over-exaggerating.