A new study from the University of Montreal concludes that the combination of being exposed to childhood violence and having a particular gene is particularly important for the development of antisocial behavior in adulthood.

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 This is stated in a news release published on Eurekalert. 


327 young men were followed over a 15-year period

The study followed 327 young men over a period of 15 years. Isabelle Ouellet-Morin, who is among the researchers behind the study, says:

We know that people who are victims of or witness to childhood violence are more likely to have antisocial tendencies as teenagers and adults. Genetic studies have also shown that this influence can be exacerbated through differences in DNA, such as the monoamine oxidase A (MAOA) gene, she explains.

The researchers wanted to build on previous research findings, as these have yielded divergent findings.

Antisocial behavior included engaging in partner violence and having symptoms of antisocial personality disorder, such as being involved in crime, high impulsivity, and not showing remorse.


Exposure to violence increases the risk of antisocial behavior

First, the researchers found that being exposed to childhood violence was associated with a higher likelihood of developing behavioral disorders in adolescence, antisocial personality disorder in adulthood, and of showing aggressive behavior toward one's partner.


Genetic differences are important for the development of antisocial behavior 

Second, the researchers found that the importance of being exposed to violence as a child was greater in those individuals who had a particular variant of the MAOA gene. In other words, people with this gene variant were more likely to develop antisocial behavior compared to people without this gene variant. 

Genetic constitution and negative life events

Isabelle Quellet-Morin believes that the study shows that the decision on how a person develops does not lie alone in the genes, but also not alone in what a person has experienced (in the environment). The question of why we become who we become is rather to be found in the combination of our genetic baggage and in what we experience.

She tells: 

The challenge now is to gain a better understanding of the mechanisms behind some of the increased vulnerability and others of increased resilience in people who are exposed to negative life experiences.