A Connection Between Genes, the Environment, and Violence

cbuech Blog Posts, HBHE 680 2 Comments

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It is common knowledge that physical traits, such as hair or eye color, are genetically inherited from one’s biological parents. Many people also know that certain disorders are caused by genetic abnormalities or occur more frequently in individuals who are genetically susceptible, as is the case in breast and colorectal cancers. There is somewhat less knowledge and more disagreement about how genes influence mental, emotional, and social factors – specifically in this case, the propensity for violence.

Over twenty years of research has shown that there are links between genetics and aggressive behaviors. For instance, deficient activity of a gene called monoamine oxidase A (MAOA) is known to increase the risk of violence in individuals who have experienced some type of childhood trauma. Minor differences in genotype can alter the expression of MAOA and moderate the effects of environmental exposures such as trauma in youth (Caspi et al., 2002). In addition to MAOA, at least four other genes have been found to be associated with antisocial behaviors such as violence (Ferguson & Beaver, 2009). While this association has been widely studied, the biology behind it was largely unknown – until recently.

In a study published a few weeks ago, behavioral geneticists from Switzerland looked at underlying neurological mechanisms related to aggression using rats as an animal model. They found that among rats psychological trauma during early life led to measurable changes in brain function and increased violent acts during adulthood. Furthermore, this study generated many new questions for future research, particularly about anti-depressants potentially reversing negative effects of trauma.

It is important to note that genes alone do not cause someone to be overly aggressive; as indicated, environment is also a key factor. Environment is a broad term that refers not only to physical surroundings but also to social interactions, which in this case mainly include childhood traumatic events. Examples of childhood trauma include witnessing violence or experiencing sexual assault. Both earlier research and the recent rat study suggest that exposure to trauma is more likely to lead to an increase in aggressive and antisocial behaviors if the individual is also genetically susceptible. This means that a specific subset of the population is at greater risk for violence, which presents a unique but challenging opportunity for violence prevention.


Comments 2

  1. While I do think this is a unique idea from a prevention standpoint, I absolutely agree that it would be a challenging opportunity for violence prevention, particularly with regard to ethical issues. If we were to promote prevention strategies or interventions for those that are genetically susceptible to aggressive and antisocial behaviors, what may be an ethical way of figuring out if one is in fact genetically susceptible? Further, if we could find out who was genetically predisposed, what could ethically be done with that individual (i.e. with their consent) to reduce their risk of perpetrating violence? Aside from the ethical considerations, another challenge with using genetic information to predict behavior is that even when an individual has a predisposition toward a certain behavior, there is no guarantee that they will carry out that behavior. There are several other personal, environmental, and societal factors that affect a person and contribute to their actions and overall behavior. Genetic information can be a great tool for prevention of disease, but it is clearly more difficult to use this information to predict behavior.

    1. This topic is one of great controversy, even within one University department studying criminology different professors take their own unique stance. Currently, I am studying biosocial studies of anti-social and violent behavior. My current professor made the claim that they believe that this is the future of criminology. In my limited knowledge I am not at a point where I can agree or disagree with that statement, but I can see where it would make sense. Currently, it seems as if theories are segregated into biological and social factor, so it makes sense to me to combine the two to get the greatest possible outcome. Not being very science-minded the biological side of things go over my head a lot, as a sociology major I tend to error on the side of social factors. A large part of me has to believe that environment trumps biology. In my understanding of biosocial studies, I believe researchers would agree with that statement. So, the question then is raised, “knowing that some individuals are genetically at higher risk, what do we do with that knowledge?” Do we test infants and children for this gene? If that is the case, I would argue that we then get into a labeling issue. Where we expect children to become delinquent and treat them as that even before their delinquent behavior starts. I think a fine line is going to be played with as biological and social factors are combined to rehab and prevent violent behavior. I definitely think that it can have a positive affect on our society I just think it may come with a cost that does not outweigh the benefits. I guess only time and trial can tell.