A new study has found that limiting teenagers’ screen time can have a positive impact on their grades. The researchers examined data on the school performance and recreational habits of 10,000 middle school students. Students who look at screens for more than an hour on school nights have significantly lower grades than those who don’t. It was also found that boys are more likely to entertain themselves using social media, the internet and video games than girls. The researchers say that excessive technology use can lead to bad study habits. They recommend limiting students’ recreational screen time to one hour on weekdays and four hours on the weekend