Both positive and negative experiences influence how genetic variants affect our brain and, with it, our behavior . Genetics then predisposes us to be antisocial or not. This is the conclusion of the latest study carried out by the University of Montreal (Canada) and published in the International Journal of Neuropsychopharmacology .
“The effects of variants of many genes that are common in the population depend on environmental factors. In addition, these genetic variants influence each other, ”explains Sheilagh Hodgins, co-author of the study.
The researchers conducted a study to determine whether juvenile delinquency could be associated with interactions between three common genetic variants: MAOA , a key enzyme in the catabolism of brain neurotransmitters; BDNF , which modulates neuronal plasticity or the ability of our brain cells to reorganize pathways and connections throughout our lives; and 5-HTTLPR , the serotonin transporter gene, and the positive and negative experiences of individuals.
For this, they had the participation of 1,337 high school students between 17 and 18 years old . All of them anonymously completed a series of questionnaires about family conflicts, crime, experiences of sexual abuse or the quality of their family relationship. They added to the questionnaires a saliva sample with which the scientists extracted their DNA.
The results revealed that variants of these three common genes interacted with each other and environmental factors such as family conflict or sexual abuse increased the likelihood of antisocial and criminal behavior . Thus, a positive environmental factor decreased the risk of both behaviors in this group of adolescents.
“These results are in addition to those of other studies showing that genes affect the brain, and therefore behavior , by altering sensitivity to the environment,” says Hodgins.
