In 2015, around one-third of 11-year-olds in the US had smartphones. Now, that number seems quaint.

According to new report from Common Sense Media about teens' and tweens' media use, more than half of 11-year-olds now have a smartphone. If that seems like a lot of sixth graders with iPhones, consider that one-fifth of eight-year-olds-that is, third graders-now have smartphones too, up from one-tenth in 2015. "That seems like a lot to me," said Michael Robb, senior director of research at Common Sense Media.

What kids do on those smartphones is changing, with more time spent watching online videos, mostly on YouTube. Among tweens (ages 8 to 12), just over half of all screen use is used watching TV or videos, while 31% is spent gaming and just 2% reading. Teens (ages 13-18) also spend the bulk of their time on videos (39%), with the balance on gaming (22%), social media (16%), and every once in a while reading (also 2%).

My daughter just turned 11. A friend with older kids recently offered this advice: "Hold off on giving her a phone as long as possible. Once she gets it, you lose her." It seems the end is near.

tag