With more and more violence seeping into movies and other media these days, the question of how it affects real-world violence has become an increasingly important one. A new study addresses this question by investigating how exposure to violence affects people with aggressive traits versus those without.
The study, published in PLOS One, was led by researchers at the Icahn School of Medicine at Mount Sinai and the National Institutes of Health (NIH) Intramural Program.
Using brain scans on individuals with different aggression levels, the researchers found that each person’s reaction to violent depictions depends on their brain circuitry and inherent aggression levels.
“Aggression is a trait that develops together with the nervous system over time, starting from childhood,” says Prof. Nelly Alia-Klein, from the Friedman Brain Institute and Icahn School of Medicine.
“Patterns of behavior become solidified and the nervous system prepares to continue the behavior patterns into adulthood when they become increasingly coached in personality,” she continues. “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.”
As such, she and her team wanted to find out what happens in the brains of aggressive and non-aggressive individuals as they watch violent movies. The researchers theorized that people with aggressive traits would process violent media differently, compared with non-aggressive people.
To start, the researchers had 54 men answer a questionnaire, after which they split them into two groups: one in which the men had aggressive traits – including a physical assault history – and another group of men without aggressive traits.
Next, the team scanned the participants’ brains as they watched violent scenes – that included shooting and street fights – on one day, non-violent scenes on the next day and nothing on the third day. The brain scans measured the men’s brain metabolic activity, which is a marker of brain function, the researchers say.
Additionally, the investigators measured the participants’ blood pressure every 5 minutes and asked them how they were feeling every 15 minutes.
When the participants with aggressive traits were not watching any movies, the researchers observed that they had unusually high brain activity in regions known to be active when not doing anything in particular, which the team says suggests these participants have a different “brain function map” than those lacking aggressive traits.
Additionally, when the aggressive men were watching scenes from violent movies, they had less brain activity in the orbitofrontal cortex – a brain region associated with emotion-related decision making and self-control – compared with the non-aggressive group.
The men from the aggressive group also said they felt more inspired and determined and less upset or nervous than the non-aggressive men while watching the violent movies versus the non-violent movies.
And the researchers observed that the aggressive participants’ blood pressure decreased progressively while watching the violent movies, whereas the non-aggressive participants had an increase in blood pressure.
Their findings could have implications for programs that intervene in childhood to reduce aggressive behavior, they say.
“Hopefully these results will give educators an opportunity to identify children with aggressive traits and teach them to be more aware of how aggressive material activates them specifically,” adds Prof. Alia-Klein.
Medical News Today reported on a study in June that suggested youths who have committed homicide display differences in brain structure. Meanwhile, another study from 2013 suggested violent video games reduce teens’ self-control.