Boys who play video games on school days spend 30 percent less time reading and girls spend 34 percent less time doing homework than those who do not play such games, U.S. researchers said on Monday.
But they said video games do not appear to interfere significantly with time spent with family and friends.
Gamers did spend less time reading and doing homework. But they didn't spend less time interacting with their parents or their friends, nor did they spend less time in sports or active leisure activities, said Hope Cummings of the University of Michigan, whose study appears in the Archives of Pediatrics and Adolescent Medicine.
The study comes as U.S. doctors voice growing concern about the long-term effects of video games.
Prior studies have linked prolonged video game play with attention difficulties and poor academic performance. And some doctors have suggested the games interfere with social development and might be addictive.
Cummings and Elizabeth Vandewater at the University of Texas at Austin wanted to see how these games affect academic pursuits and social relationships.
They gathered data from a nationally representative sample of kids aged 10 to 19 in 2002 who tracked their activities on a random weekday and a random weekend day.
Of the 1,491 who participated, 534 adolescents or about 36 percent played video games. About 80 percent were boys.
They found boys spent an average of 58 minutes playing on weekdays and one hour and 37 minutes playing on a weekend day. Of those sampled, girls spent 44 minutes playing on a weekday and an hour and four minutes on a weekend day.
Cummings and colleagues found video game use resulted in less time spent reading and doing homework, and these trade-offs fell along gender lines.
The reading was just for the boys. For the homework, it was just the girls, she said in a telephone interview.
Gaming did not seem to affect time spent doing homework among boys or reading among girls, the study found.
Also, gamers did not spend less time with friends and parents.
These findings do not support the notion that adolescents who play video games are socially isolated, the authors wrote.
They also said the findings indicate that video game play can be a distraction from school-related activities, but that may not hurt grades.
Although gamers spend less time reading and doing homework, there have been some studies that show that high academic achievers spend less time doing homework, Cummings said.
Gamers may actually be more effective in completing homework assignments, and as a result, they spend less time doing homework. We need to look deeper into what is going on, she said.