If we didn’t already believe that violent video games and movies were bad for our kids’ mental health, a new study looking at the connection between the two variables in young people around the world drives the point home in a convincing and startling way.

A team of researchers from Iowa State University examined data from over 2,100 young people representing a wide range of countries: Australia, China, Croatia, Germany, Japan, Romania and the United States. They asked the participants, who were 38% male and an average of 21 years old, about their video game use, as well as movie and TV watching. Participants also answered personal questions about their backgrounds, upbringing and violent behavior. Five other factors besides violent media use were measured to see if they were correlated with violent behavior: neighborhood crime, delinquency, bullying, gender and abusive parenting.

Violence may sell in the short-term, but in the long-term, it’s probably wiser and even more economical to put the mental health of our kids first.

Delinquency was the greatest predictor of violent behavior, but media violence came second — and it was linked to violent behavior in all of the countries included in the study. Media violence was also linked to more aggressive thinking and less empathy. Peer victimization, gender, neighborhood crime and abusive parenting also played roles in aggressive behavior, but all were less significant than violent media.

“The findings strongly suggest that media violence is similar to other known risk factors for aggression,” study author, Douglas Gentile, said in a news release. “That's not to say media violence deserves special attention, but that it should be considered as seriously as other risk factors such as coming from a broken home. What matters most, however, is not any single risk factor, but how they can combine to increase the risk of aggression.”

Evidence for the media-violence connection is nearly irrefutable at this point, the authors say, but there are still plenty of people who continue to deny it, most likely because violence sells. “There are highly motivated groups dedicated to denying scientific findings of harm, much as the tobacco industry's decades-long denial of harmful effects of their products on cancer,” said study author, Craig Anderson. “This study clearly contradicts the denialism that currently dominates news media stories on media violence effects.”

Parents and policymakers need to realize that kids actually seem to prefer action to violence. Perhaps video game developers should take this type of research into consideration as they develop new online entertainment, and create games that harness the exciting parts of the violent video games without the violence. It might make a big difference to kids’ psychological health as they grow up.

“This study clearly contradicts the denialism that currently dominates news media stories on media violence effects.”

The psychological processes that cause exposure to media violence to lead to increased aggressiveness are essentially the same across cultures, Anderson insists. It’s not clear whether people in countries that are experiencing war or social unrest are more or less affected by media violence than others, but the researchers “...believe that local cultural and social conditions may influence such processes when those conditions are more extreme.”

The bottom line is that the connection between media violence and violent behavior does seem to exist everywhere, and points to a fundamental relationship between the violence that we experience virtually and the violence that we act out in reality. Violence may sell in the short-term, but in the long-term, it’s probably wiser and even more economical to put the mental health of our kids first.

The study is published in the journal Personality and Social Psychology Bulletin.