A new study from researchers at Oxford University found that video games can be good for children, but only if they play for around an hour or less per day.

The study, published today in Pediatrics, found that children who played games for a few hours each week were better adjusted, had fewer conduct problems, and better empathized with others than those who played no games at all, according to a breakdown of the report from Today and BBC.

When children started playing one to three hours per day, the positive effects fell away. According to the study of 5,000 girls and boys aged 10-15, children who played even more than that were more likely to have issues with hyperactivity and inattention, show a lack of compassion for others, and generally feel less satisfied with life.

The study’s author, Oxford experimental psychologist Andrew Przybylski, said he hopes the results will comfort parents who think playing video games is harmful for their children. Future studies on the subject should look at other aspects of gaming, including children’s motivations for play and the “structural affordances of different kinds of gaming contexts,” Przybylski said.

You can read the study at the Pediatrics website.