Children and adolescents had been watching a lot of television since the 1950s, but the new technologies were far more portable, personalized, and engaging than anything that came before. Parents discovered this truth early, as I did in 2008, when my two- year- old son mastered the touch- and- swipe interface of my first iPhone. Many parents were relieved to find that a smartphone or tablet could keep a child happily engaged and quiet for hours. Was this safe? Nobody knew, but because everyone else was doing it, everyone just assumed that it must be okay. 

Yet the companies had done little or no research on the mental health effects of their products on children and adolescents, and they shared no data with researchers studying the health effects. When faced with growing evidence that their products were harming young people, they mostly engaged in denial, obfuscation, and public relations campaigns. Companies that strive to maximize “engagement” by using psychological tricks to keep young people clicking were the worst offenders. They hooked children during vulnerable developmental stages, while their brains were rapidly rewiring in response to incoming stimulation is included social media companies, which inflicted their greatest damage on girls, and video game companies and pornography sites, which sank their hooks deepest into boys. By designing a firehose of addictive content that entered through kids’ eyes and ears, and by displacing physical play and in- person socializing, these companies have rewired childhood and changed human development on an almost unimaginable scale (Pages 3 and 4). 

I propose that we view the late 1980s as the beginning of the transition from a “play-based childhood” to a “phone- based childhood,” a transition that was not complete until the mid- 2010s, when most adolescents had their own smartphone (page 7). I use “phone- based” broadly to include all of the internet- connected personal electronics that came to all young people’s time, including laptop computers, tablets, internet- connected video game consoles, and, most important, smartphones with millions of apps.

As the transition from play-based to phone-based childhood proceeded, many children and adolescents were perfectly happy to stay indoors and play online, but in the process they lost exposure to the kinds of challenging physical and social experiences that all young mammals need to develop basic competencies, overcome innate childhood fears, and prepare to rely less on their parents. Virtual interactions with peers do not fully compensate for these experiential losses. Moreover, those whose playtime and social lives moved online found themselves increasingly wandering through adult spaces, consuming adult content, and interacting with adults in ways that are often harmful to minors. So even while parents worked to eliminate risk and freedom in the real world, they generally, and often unknowingly, granted full independence in the virtual world, in part because most found it diffcult to understand what was going on there, let alone know what to restrict or how to restrict it.

My central claim in this book is that these two trends— overprotection
in the real world and underprotection in the virtual world— are the major
reasons why children born after 1995 became the anxious generation (page 9).