An individual's genetic makeup dictates many things. From the way we look to the medical conditions or diseases we are born with or later develop, much is predetermined by an individual's genes. The role that genes play in influencing behavior is an area of great interest to scientists and sociologists who aim to discover the role genes play in influencing behavior.
In a recent study, researchers looked at the genetic makeup of 900 Finish residents who were incarcerated for both violent and nonviolent crimes. When comparing the genetic compositions of both groups, researchers noted two specific genes that individuals convicted of committing violent crimes like murder possessed that nonviolent offenders did not.
One of the genes identified, MAOA, is critical in helping regulate the brain's secretion of the chemicals dopamine and serotonin. The other identified gene, cadherin 13, is linked to both addiction and attention deficient disorder. Based upon their findings, the study's authors determined that individuals who possess these genes are "13 times more likely to have a history of repeated violent behavior."
In addition to genetics, researchers also point to environmental factors when discussing criminal behavior. For example, the effects of alcohol and drugs appear to often play a contributing role in influencing behavior, particularly when it comes to violent crimes.
While researchers are quick to point out the role of free will and that not all individuals who possess the MAOA and cadherin 13 genes will exhibit violent behavior, the discovery of these genes and their strong correlation with violent crime is noteworthy and deserves further investigation and review.
Source: BBC, "Two genes linked with violent crime," Melissa Hogenboom, Oct. 28, 2014