Jonathan Haidt and Jean M. Twenge warn that we need to separate teenagers from their smartphones:

Teenage loneliness was relatively stable between 2000 and 2012, with fewer than 18 percent reporting high levels of loneliness. But in the six years after 2012, rates increased dramatically. They roughly doubled in Europe, Latin America and the English-speaking countries, and rose by about 50 percent in the East Asian countries . . .

All young mammals play, especially those that live in groups like dogs, chimpanzees and humans. All such mammals need tens of thousands of social interactions to become socially competent adults. In 2012 it was possible to believe that teens would get those interactions via their smartphones — far more of them, perhaps. But as data accumulates that teenage mental health has changed for the worse since 2012, it now appears that electronically mediated social interactions are like empty calories. Just imagine what teenagers’ health would be like today if we had taken 50 percent of the most nutritious food out of their diets in 2012 and replaced those calories with sugar.

So what can we do? We can’t turn back time to the pre-smartphone era, nor would we want to, given the many benefits of the technology. But we can take some reasonable steps to help teens get more of what they need.