The Anxious Generation: How the Great Rewiring of Childhood Is Causing an Epidemic of Mental Illness

by Jonathan Haidt

IN SUM In this chapter I described the four foundational harms of the phone-based childhood. These are profound changes to childhood caused by the rapid technological shift of the early 2010s. Each one is foundational because it affects the development of multiple social, emotional, and cognitive abilities. The sheer amount of time that adolescents spend with their phones is staggering, even compared with the high levels of screen time they had before the invention of the iPhone. Studies of time use routinely find that the average teen reports spending more than seven hours a day on screen-based leisure activities (not including school and homework). The opportunity cost of a phone-based childhood refers to everything that children do less of once they get unlimited round-the-clock access to the internet. The first foundational harm is social deprivation. When American adolescents moved onto smartphones, time with friends in face-to-face settings plummeted immediately, from 122 minutes per day in 2012 down to 67 minutes per day in 2019. Time with friends dropped further because of COVID restrictions, but Gen Z was already socially distanced before COVID restrictions were put in place. The second fundamental harm is sleep deprivation. As soon as adolescents moved from basic phones to smartphones, their sleep declined in both quantity and quality, around the developed world. Longitudinal studies show that smartphone use came first and was followed by sleep deprivation. Sleep...