螢幕時間對兒童大腦的影響比看起來更複雜

Many parents today are concerned about how much time their children spend on screens, whether it is a tablet, smartphone, or computer. Zoe Kleinman, a technology editor, shared her personal experience of giving her young son an iPad to keep him entertained while she did chores. When she tried to take it away, he had a major tantrum, which made her question if screens are really as harmful as people say. This worry is not new. Even Steve Jobs, the former CEO of Apple, did not allow his own children to use iPads when they were young. Bill Gates also set limits on his children's use of technology. There is a lot of talk about screen time being linked to problems like depression, sleep issues, and bad behavior in children. Some scientists, like Baroness Susan Greenfield, have warned that too much screen time could harm children's brains. She even compared the risks to the early days of climate change, saying people were not taking it seriously enough.

However, not everyone agrees with these warnings. Some experts argue that the evidence is not as clear as it seems. For example, a group of UK scientists recently said that there is not enough solid proof that screens are really causing harm. Pete Etchells, a psychology professor, has studied hundreds of reports about screen time and mental health. In his book, he says that the science is mixed and sometimes flawed. He points out that many studies rely on self-reporting, where children are asked to remember how much time they spent on screens and how it made them feel. This is not always accurate. He also warns that just because two things happen at the same time does not mean one causes the other. For example, more people eat ice cream and get sunburned in the summer, but ice cream does not cause sunburn.

A study by the American Psychology Association in 2021 looked at 33 studies and found that screen use, including social media and video games, played only a small role in mental health problems. Another review of 11 studies found no strong evidence that the blue light from screens makes it harder to sleep. Some research suggests that loneliness, rather than screen time itself, is a bigger factor in mental health issues among young people. Not all screen time is the same, either. Some children use screens to learn, connect with friends, or have fun, while others might spend time scrolling through negative news. Each type of screen use can have a different effect.

A large study looked at brain scans of over 11,000 children and found no evidence that screen time was linked to poor mental health or thinking problems, even for those who used screens for several hours a day. Some experts even believe that screens can help children feel better and learn new things. However, there are real dangers online, such as exposure to harmful content or talking to strangers. Some people worry that strict rules about screen time might make children want to use screens even more, turning them into a 'forbidden fruit.

There are groups, like Smartphone Free Childhood in the UK, that want to ban smartphones for children under 14 and delay social media until age 16. Some studies show that reducing screen time can improve children's mood and behavior, but more research is needed. Official advice is inconsistent. The World Health Organization recommends no screen time for children under one and only one hour a day for those under four, but other organizations do not set strict limits.

Parents often feel judged about how they handle screen time. Some are strict, while others are more relaxed. The truth is, there is not enough science to say for sure what is best. Technology is always changing, and screens are a big part of life now. It is important for parents to think about what works for their family and to help children use screens in a healthy way.

As technology continues to evolve, it is important to keep learning and talking about what is best for children. Parents, teachers, and scientists all need to work together to help children grow up healthy and smart in a world full of screens.