Jonathan Haidt

When we graph out all of these mental illness stats, the boys are doing worse too, no question about it. But the boys' curves are gradual, whereas the girls, it's stable from the 90s on most things through 2011. And then 2012 is like a hockey stick, and it goes up very sharply. And I think it's because...

When we graph out all of these mental illness stats, the boys are doing worse too, no question about it. But the boys' curves are gradual, whereas the girls, it's stable from the 90s on most things through 2011. And then 2012 is like a hockey stick, and it goes up very sharply. And I think it's because...

Before then, the girls were connecting on their flip phones and then getting together in person. That's perfectly healthy. When you get a sudden movement of everyone onto social media and now you've got all this social comparison and all this people expressing anxiety. And if you're expressing anxiety, I'm going to be more anxious.

Before then, the girls were connecting on their flip phones and then getting together in person. That's perfectly healthy. When you get a sudden movement of everyone onto social media and now you've got all this social comparison and all this people expressing anxiety. And if you're expressing anxiety, I'm going to be more anxious.

So I think that's why we see such a sudden change for the girls is the contagion of emotions.

So I think that's why we see such a sudden change for the girls is the contagion of emotions.

Thank you for pulling me back from the doom and gloom because I can go on forever.

Thank you for pulling me back from the doom and gloom because I can go on forever.

Okay, so let's hope that nobody tuned out before this point of the conversation. So here's what I can say with some confidence. The brain is still pretty plastic until the early 20s. In puberty, so the brain is changing very rapidly in the first couple years, and it's growing very rapidly. But then it reaches full size, almost full size, by about age six. And after that, the game is not growth.

Okay, so let's hope that nobody tuned out before this point of the conversation. So here's what I can say with some confidence. The brain is still pretty plastic until the early 20s. In puberty, so the brain is changing very rapidly in the first couple years, and it's growing very rapidly. But then it reaches full size, almost full size, by about age six. And after that, the game is not growth.

The game is like which neurons are going to wire up to which, which neurons are going to disappear. And so they're tuning up with cultural input. And it especially speeds up in early puberty. I want everybody to really focus on early puberty. Try to protect your kids during that period. But suppose your kid is 15, she or he has already been on the video games, the social media.

The game is like which neurons are going to wire up to which, which neurons are going to disappear. And so they're tuning up with cultural input. And it especially speeds up in early puberty. I want everybody to really focus on early puberty. Try to protect your kids during that period. But suppose your kid is 15, she or he has already been on the video games, the social media.

One possibility is that the changes could be long-lasting. It is possible that if you went through puberty this way, it could change things in ways that are lasting. We don't know. But here's what I can say for sure. When kids take steps to regain control of their attention, they get miraculous results. And I know this because I teach a class at New York University.

One possibility is that the changes could be long-lasting. It is possible that if you went through puberty this way, it could change things in ways that are lasting. We don't know. But here's what I can say for sure. When kids take steps to regain control of their attention, they get miraculous results. And I know this because I teach a class at New York University.

I'm a professor in the business school there. And I teach one of my classes called Flourishing, and it's 35 undergraduates. They're mostly sophomores, about 19 years old. They all spend too much time on their phones. And the project is you have to, over the course of the semester, you have to change yourself in a way that will improve your happiness and flourishing by the end of the semester.

I'm a professor in the business school there. And I teach one of my classes called Flourishing, and it's 35 undergraduates. They're mostly sophomores, about 19 years old. They all spend too much time on their phones. And the project is you have to, over the course of the semester, you have to change yourself in a way that will improve your happiness and flourishing by the end of the semester.

So a lot of them work on their phone habits. And I say, if you're spending three hours a day or more on social media, you have to work on this one because there's no point doing anything else. And the ones who are doing a lot of social media and some are like five or six hours just on TikTok, when they move it off their phone and onto their computer, they get a lot of relief. It goes way down.

So a lot of them work on their phone habits. And I say, if you're spending three hours a day or more on social media, you have to work on this one because there's no point doing anything else. And the ones who are doing a lot of social media and some are like five or six hours just on TikTok, when they move it off their phone and onto their computer, they get a lot of relief. It goes way down.

And then if they take it off the computer and just stop, especially for TikTok, they tell these miraculous stories like... I can do my homework now. It's not just that I have enough time, it's that I can actually focus on it, and I have more time with my friends, and we're doing fun things, and I'm sleeping better.

And then if they take it off the computer and just stop, especially for TikTok, they tell these miraculous stories like... I can do my homework now. It's not just that I have enough time, it's that I can actually focus on it, and I have more time with my friends, and we're doing fun things, and I'm sleeping better.