Is Violent Behavior a Result of Nature or Nurture, or Both?
Nature Versus Nurture
As we journey through life attempting to figure out who we are and why we think and act and feel the way that we do, a common theory that arises is the evolutionary theory of nature and nurture. Nature being, our genetic dispositions and nurture, the way our environment shapes who we are.
As a parent, I often observe certain behaviors in my children that remind me of a family member. Typically it is their father or me but sometimes it is a distant relative that they don’t get to see often. One question that is constantly on my mind is “Who do they get this from?” When my daughter acts like her father I wonder if it is because she is his daughter or because she is around him constantly. Either could be the case, or it could be the two, nature and nurture, working together. However when she shows a similarity in behavior to a relative that she rarely spends time with, I have to think that genetics might be credited to that.
In the article, Nature and Nurture Predispose to Violent Behavior: Serotonergic Genes and Adverse Childhood Environment, the authors hypothesize that genetics as well as environmental factors influence human behavior. The researches wanted to distinguish a difference between offensive and defensive aggression, hoping it would help understand the neurobiological side of aggressive behavior. Early childhood environmental factors such as unfavorable child upbringing have proven to contribute to aggressive behavior in children, and this kind of behavior as a child is typically followed by similar aggressive and antisocial behavior as an adult.
The study was conducted on 184 adult males who were all Caucasian, each was assigned to either a “violent crimes” or non-violent crimes” group according to their histories. Violent crimes were considered to be things like homicide and physical injury, while non-violent crimes were things such as drug offenses and fraud. Variables such as age, history of drug addiction, history of personality disorder, adverse childhood environment as well as different genotypes were measured with violent behavior being the dependent. Simply, the results of the study indicated that genotype and adverse childhood environment both independently increased the risk for later in life violent behavior.
The results seemed to all indicate that genetics in one way or another, as well as environmental influence were always participants in the development of violent behavior. I agree with the methods used to carry out the research the study seems to have valid results. The study made me feel as if nature was more significant than nurture which is something I do not entirely agree with.
Although this study was very convincing in the points made for genetics, it also made positive credits toward the environmental aspects as well. I think that the information is partially limited because the testing was conducted on only one gender and one race. Women can certainly exhibit violent and aggressive behavior just as well as men and so can other races. It would be interesting to see the results of the same study, done on women and then others done on men or women of other cultures. If the aggressive behavior is more inherited than not, perhaps those factors also play a role in the genetics of it.
It is hard to deny that personality traits often do seem to be inherited. For example, an article titled Nurture versus nature: evidence of intrauterine effects on suicidal behavior, states that depression and aggression and impulsivity are all related to suicidal behavior and are all heritable. That being said, the article also points out that environmental factors even before birth could play an important role in the development of behavior. A depressed woman may very well not take care of herself properly during pregnancy causing a poor prenatal environment for the baby. It’s suggested that things like intrauterine stresses like poor maternal nutrition and environmental factors like childhood neglect and abuse can actually lead to changes in the methylation of genetic material.
Another article of interest is Behavioral Epigenetics: How Nurture Shapes Nature. Like the article title indicates, behavioral epigenetic studies how environment triggers changes in brain structure. The author states that “the term environment encompasses pretty much everything that happens in every stage of life: social experience; nutrition, hormones, and toxicological exposures that occur prenatal, postnatally, and in adulthood”. When you think of environment that way it is hard to argue that it can obviously affect our bodies in ways that one would instinctively think was genetics.
I think the answer is both.
When I think about instances where I have personally witnessed aggressive and violent behavior, I must admit that it often seems like the person exhibiting the behavior is almost copying the behavior of a parent. It makes a strong case for the nature side; however when you are brought up by someone you often learn to react the way that they react so that is where nurture can also be blamed. In the end, despite what I considered limitations of the study, I would have to agree with the original article that nature and nurture both play an important role in violent behavior. I strongly believe in environmental factors playing an important role in development and behavior, but I can’t ignore the evidence that in so many cases the behavior seems to be a genetic trait inherited from a parent.
Magnavita, J. J. (2012). Theories of Personality. San Diego: Bridgepoint Education Onc.
Oquendo, M. A.-G. (2004). Nurture versus nature: Evidence of intrauterine effects on suicidal behaviour. The Lancet, 364(9440), 1102-4. Retrieved from http://search.proquest.com/docview/198990172?accountid=32521.
Powledge, T. M. (2011). Behavioral epigenetics: How nurture shapes nature. Bioscience, 61(8), 588-592. Retrieved from http://search.proquest.com/docview/883393359?accountid=32521 .
Reif, A. R. (2007). Nature and Nurture Predispose to Violent Behavior: Serotonergic Genes and Adverse Childhood Environment. Neuropsychopharmacology. 32, 2375-2383. Retrieved from http://www.nervenklinik.uk-wuerzburg.de/fileadmin/uk/psychiatrie/Dokumente/Forschung/Psychiatric_Neurobiology_and_Bipolar_Disorder_Program/MAO-A_and_violent_crime.pdf.