A man firing a gunDoes watching violent television or movies really make people more aggressive? It depends on your brain, according to a new study from that Icahn School of Medicine at Mount Sinai and the NIH Intramural Program. The researchers discovered that an individual’s reaction to violent media depends on the wiring of his or her brain. People with aggressive traits exhibit less brain activity in area of the brain associated with self-control when confronted with violent media. The findings could help people manage their reactions to violent television, movies, or video games.

The researchers wanted to find out what happens inside the brain when people watch violent movies. The research team hypothesized that people with aggressive traits would process media differently than people without aggressive traits. The participants—54 men—answered a questionnaire at the beginning of the study. Based on the results, the researchers divided the men into two groups: a group comprised of men with aggressive traits, including a history of physical assault, and a group comprised of men without aggressive traits.

For each of the study’s three days, the researchers scanned the participants’ brains’ metabolic activity, which is a measure of brain function. The researchers took the participants’ blood pressure every five minutes and asked the participants how they felt every 15 minutes. On the first day of the study, the participants watched violent movie scenes that depicted shooting and street fights. On the second day, they watched emotional, non-violent videos, depicting scenes like people interacting after a natural disaster. On the third day, they did not watch anything.

The participants from the aggressive and non-aggressive groups exhibited differing levels of activity in the brain’s orbitofrontal cortex, a part of the brain associated with emotion-related decision making and with self-control. When watching violent scenes, the aggressive group had less activity in the orbitofrontal cortex than the non-aggressive group. Aggressive participants reported feeling more inspired and determined after watching violent media. The blood pressure of aggressive individuals decreased over time while watching violent media. In contrast, the non-aggressive participants felt upset or nervous in response to violent media and their blood pressure increased.

“Aggression is a trait that develops together with the nervous system over time starting from childhood; patterns of behavior become solidified and the nervous system prepares to continue the behavior patterns into adulthood … This could be at the root of the differences in people who are aggressive and not aggressive, and how media motivates them to do certain things,” stated lead investigator Nelly Alia-Klein, PhD, Associate Professor of Neuroscience and Psychiatry at the Icahn School of Medicine.

This research is published in the journal PLOS One.

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