Dartmouth researchers have published the results of a meta-analysis of 24 studies from around the world and found that they point to children becoming more aggressive as they play violent video games. According to the study, which was earlier reported on by USA Today, the aggression would begin between three months and four years after children started playing violent video games. Their behavior included fighting at school or hitting someone other than a family member, according to the report.

The 24 studies were conducted between 2000 and 2017 across the U.S., Canada, Germany, and Japan. They included a total of 17,000 students between the ages of nine and 19 years. The researchers analyzed the results of all of those studies to determine whether there is a link between violent video games and physical aggression.

“Based on our findings, we feel it is clear that violent video game play is associated with subsequent increases in physical aggression,” the study’s lead author Jay Hull said in the Proceedings of the National Academy of Sciences journal, according to USA Today.

The possible link between violent video games and childhood aggression has been studied and debated for years. And either side of the debate makes impassioned arguments for its beliefs. Hull even acknowledged that while the “effect does exist” of video games causing aggression in children, it’s still “relatively small.”

It is clear, however, that video games have become more realistic and have a variety of violent elements. And the chances of that reversing course are slim. Looking ahead, Hull said in the paper that he believes researchers should use the findings to dig deeper into the effects video games have on children and who might be at the greatest risk of being affected.