Very often, when we see young people sitting there, looking at the screen of a mobile phone and smiling, we may think nothing is wrong. But when we come to the question "how much time do they actually spend on media daily?", the answer is surprising: young people spend about nine hours every day using media, and this only includes media used for enjoyment.

Today's young people seem to have become crazy multitaskers. They often use media when doing other activities. Some watch TV when doing homework, some text, and some others listen to music. But what do young people think of this? A research showed that two thirds of them believed watching TV or texting had no influence on schoolwork. Half of them thought using social media made no difference. However, researches have given a different answer: "media multitaskers" did worse in tests.

Scientists did a research among more than 400 students. It shows that those who text a lot have more trouble sleeping and do worse in their study. In another research, students who didn't text during a lesson took down a lot more notes than those who were texting. A similar research also found that students who texted when doing schoolwork had lower overall(总体的) grades.

According to a research, if a kid uses social media a lot, especially at night, he or she will sleep worse and feel more nervous and depressed. On the one. hand， young people stay up late to check messages and information. They may also be woken up by messages they receive. On the other hand, even the light from a screen could influence their sleep. Some other researches also show that children who use media at night go to bed later, get fewer hours of sleep each week, and become sleepy more easily during the daytime.