Friday, February 27, 2015

The Warrior Gene and Criminal Behaviour

Acts of violence and extreme violence are often attributed to mental instability.  In addition, violent behaviour can also lead one to commit an act of violence. While the general conception is often rooted within how criminals think, a significant molecular component takes into account for violent behaviour. Dr. James Fallon, in his book The Psychopath Inside, discusses how genes affect certain kinds of behaviour. He introduces this concept by discussing genetics, the effects of different neurotransmitters, and SNPs. All three of these factors have influenced the transmissions and regulation of certain genes that contribute to violent behaviour. He takes a while to discuss the MAO-A enzyme and the warrior gene and how that affects brain behaviour, most notably in accordance to violence. An article by Melissa Hogenboon, a correspondent for BBC science, compiled an article in which she found two genes that contribute to violent behaviour: MAOA gene (same as Fallon) and another called the CDH13 gene.
            Hogenboom’s article explained that 900 offenders underwent a genetic analysis. A profile was given to each offender and his or her offenses had to be categorized into violent and non-violent. Those who were categorized in “violent” were shown to have a low activity version of the MAOA enzyme. A deficiency of this causes dopamine levels to rise. Fallon discusses the effect of MAO-A in his book and explains that the enzyme often leads to an aggressive behaviour. The MAO-A enzyme is in accordance to the warrior gene. The warrior gene creates MAO-A. MAO-A gene codes for monoamine oxidase A. Monoamine oxidase A controls the levels of dopamine within the body. In addition to MAO-A, a variation of a cadherin (CDH13) is linked with ADHD and substance abuse. MAO-A and CDH13 were not found in non-violent offenders. According to Fallon, the warrior gene causes MAO-A to be under-produced. When MAO-A is under-produced, monoamine is unable to be broken down. Thus, a surplus of monoamines arises and that includes serotonin. This causes the brain to create fewer receptors for serotonin and ends up changing the connection, structure, and size of cells. Therefore, this whole brain area is changed. Fallon introduced a study that was done by a Dutch researcher in which men with a low production of MAO-A were shown to have inappropriate behaviour and committed crimes. This correlates with the study done that was stated in the article by Hogenboom, that those with a deficiency of MAO-A showed aggressive behaviour. Fallon also states that the warrior gene is linked to show changes in brain structure, primarily in males. The areas that were changed were linked to show antisocial behaviour and psychopathy. Since the warrior gene is located on the X chromosome, the gene tends to affect males more.
            Genetics and biology are crucial factors in determining our behaviour. Our violence and aggression can be attributed to our biology, our brain, and our genes. When we think of crime, we think of the person. However, we do not have a tendency to delve deeper and find reasons why such behaviour and aggression exist. Now, as Fallon stated, we are finding ways to determine what particular genes are associated with certain symptoms. Through that, we are able to diagnose and determine certain behaviours. While Hogenboom’s article also agrees that we should consider biology, the article clearly takes the position that environmental factors should be taken into account, a contrasting view of Fallon’s. Therefore, alleles and genes can be further studied in order to determine certain behaviours and how it affects the brain.

Two genes linked with violent crime. (2014, October 1). Retrieved February 27, 2015, from http://www.bbc.com/news/science-environment-29760212

Fallon, J. (2013). The psychopath inside: A neuroscientist's personal journey into the dark side of the brain. New York: Current.



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