Gone are the days of teenagers being content with climbing trees and playing basketball in their free time. Nowadays, they are more likely to be found playing video games. But new research suggests that teenagers who play violent video games are more likely to cheat, experience increased aggression and have reduced self-control.

This is according to a study published in the journal Social Psychological and Personality Science.

A team of researchers from the US, Italy and the Netherlands analyzed 172 Italian high school students aged between 13 and 19, who were required to take part in a series of experiments to determine how violent video games affected their personalities.

For the first experiment, participants were required to play either a non-violent video game (Pinball 3D or MiniGolf 3D), or a violent video game (Grand Theft Auto III or Grand Theft Auto: San Andreas).

While they were playing the games, a bowl containing 100g of chocolate was placed next to the computer.

The researchers told the participants they could freely eat the chocolate, but warned them that it was unhealthy to consume high amounts of candy in a short space of time.

Results revealed that participants who played violent video games ate more than three times as much chocolate, compared with those who played the non-violent video games.

The teenagers were then asked to solve a 10-item logic test. For each question they answered correctly, they were rewarded with one raffle ticket that they could exchange for prizes.

The investigators told the participants how many questions they answered correctly and asked them to take the correct amount of raffle tickets from an envelope. However, the researchers knew how many tickets were in each envelope so they would know if any of the participants had taken more tickets than they had earned.

Results from this experiment revealed that the teenagers who played violent video games cheated more than eight times more, compared with those who played non-violent video games.

Another test involved the monitoring of the participants’ aggression after they played the video game against an unseen “partner,” who actually did not exist. The player who won could “blast” the losing player with a loud sound through headphones.

Teenagers who played the violent video games blasted the unseen partners with louder and longer noises, compared with those who played the non-violent games.

Commenting on the findings, Brad Bushman, professor of communication and psychology at Ohio State University and co-author of the study, says:

We have consistently found in a number of studies that those who play violent games act more aggressively, and this is just more evidence.”

The investigators also used a Moral Disengagement Scale as part of the study.

This scale measures the extent to which people hold themselves to high moral standards in a variety of situations. For example, a statement presented to the participants was: “Compared to the illegal things people do, taking some things from a store without paying for them is not very serious.”

The higher the participants scored, the more they were morally disengaged.

The results revealed that of the participants who played the violent video games, those who scored higher on the Moral Disengagement Scale were more likely to act aggressively, cheat and eat more chocolate.

Bushman says this finding helps to identify the teenagers who are most likely to be affected by violent video games:

Very few teens were unaffected by violent video games, but this study helps us address the question of who is most likely to be affected. Those who are most morally disengaged are likely to be the ones who show less self-restraint after playing.”

The researchers say it was interesting to find that both males and females were affected in a negative way by violent video games, noting that a major risk factor for anti-social behavior is “simply being male.”

“But even girls were more likely to eat extra chocolate and to cheat and to act aggressively when they played Grand Theft Auto versus the mini golf or pinball game,” Bushman adds. “They didn’t reach the level of the boys in the study, but their behavior did change.”

Earlier this year, Medical News Today reported on a study suggesting that taking away children’s video games may not improve their fitness levels.