A large study of children in Singapore shows how violence in video games affects a child’s view of aggression.

A new study suggests that violent video games really can alter a child’s view of aggression.

The study, published today in the journal JAMA Pediatrics, surveyed the gaming habits of 3,034 children ages 8 to 17 in Singapore over a three-year period. The results suggest that violent video game play influences aggressive behavior by producing lasting changes in how a child views violence.

Video game violence expert Douglas A. Gentile, Ph.D., a developmental psychologist at Iowa State University, Ames, says his study also combats the popular belief that video game violence only affects people who are already highly aggressive. The new study also throws a wrench in the argument that girls are more immune to the aggressiveness displayed in video games.

“Because of the large number of youths and adults who play violent video games, improving our understanding of the effects is a significant research goal that has important implications for theory, public health, and intervention strategies designed to reduce negative effects or to enhance potential positive effects,” the study concluded.

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Violence in video games has been a hotly debated topic since modern gaming was invented, and the research into its effects is mixed.

Games that portray military or criminal violence, such as Grand Theft Auto and Call of Duty, are common, but also carry the strictest ratings, warning parents and potential players about the games’ adult content.

Previous studies have shown that video games that portray violence as fun, justified, or without negative consequences can alter a child’s views on aggression and empathy.

The new study replicated previous findings on the subject, including the discovery that violent video game play increases a child’s long-term aggressive behavior by “producing general changes in aggressive cognitions… regardless of sex, age, initial aggressiveness, and parental involvement.”

The new study, however, has drawbacks. Researchers warn that their conclusions should be interpreted with caution.

The information—including the number of violent acts in a video game—were reported by the children being studied, which could have introduced bias into the results. Further research, the study authors said, should include information gathered from parents, teachers, and researchers’ own observations.

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The issue of violence in video games is most often brought up in the press after mass shootings, including the Sandy Hook massacre that took the lives of 28 people. While the two are often fodder for the media, it’s a conversation normally directed by conjecture and speculation.

Only a handful of defense attorneys have brought up violent video games when trying to offer a justification for such crimes, and no defendant has ever been acquitted in a U.S. courtroom because of his or her gaming preferences.

The American Psychological Association performed a review of the subject in 2010 and found that hostility related to video games affected a certain subset of children who possess the “perfect storm” of traits: neuroticism, low levels of agreeableness (or empathy), and low levels of conscientiousness.

“Violent video games are like peanut butter,” Christopher J. Ferguson, of Texas A&M International University said of that research. “They are harmless for the vast majority of kids but are harmful to a small minority with pre-existing personality or mental health problems.”

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