Jonathan Haidt says phones replaced 300 million years of play-based childhood

In Jonathan Haidt's account, for roughly 300 million years, since the first mammals, childhood meant the same thing, lots of free play to wire up the brain.

Haidt, a social psychologist, argues that this explains why human childhood is so long and so strange. Unlike other animals, including chimpanzees, human children grow fast after birth, then slow down and stay small for years. The delay has a purpose, he says. Humans survive by culture, by learning from elders and others ahead of them, and that takes a big brain grown slowly. It also takes play, because young mammals practice adult skills by playing, joking, wrestling, exploring, and hanging around together.

Around 2010 to 2015, Haidt argues, that play-based childhood was replaced by a phone-based childhood, and development was blocked.

Consider two children. A child born in 1990 hit puberty around 2002 or 2003 with a flip phone. He or she used it to call or text friends one on one, then met up in the real world. A child born in 2000 was seven when the iPhone arrived, had a front-facing camera by 2010, likely had a phone by age 11, and was on Instagram by 12. Puberty arrived while scrolling feeds, reacting to posts, sharing photos, and worrying how people would react, often without meeting friends in person. Half of kids now say they are online almost all the time.

To feel what was lost, Haidt asks readers over 35 or 40 to remember their own childhoods, the laughing with friends, the eye contact and smiles, the books and hobbies and unsupervised time behind a shop or beside a creek or on the playground. Then cut that by 70 to 80 percent. That, he says, is what happened to the generation that followed. In his account, they get almost no time away from adult supervision, little book reading, and far less face-to-face contact. He notes American kids now average seven to nine hours a day on entertainment screens, not counting school.