MOUNTAIN VIEW, CALIF.—Jake Lee, a tanned California teenager in baggy shorts and a T-shirt, is lounging on the floor of his parents’ midcentury home. They live in a suburban Silicon Valley enclave of tech workers, cyber-savvy kids, and the occasional Google self-driving car that whirs past along pristine, eucalyptus-lined streets. He flicks through his iPhone, his fingers moving with the speed and dexterity of a jazz pianist, as he answers the sporadic text message.
“I’m on social media every waking moment of my life,” he says, with no particular pride. “I could be, like, Snapchatting and Instagram messaging the same person at the same time.”
Equidistant between the headquarters of Apple and Facebook, two of the world’s biggest tech companies, the Lee household is something of a petri dish for the way technology has altered American family life. Since it debuted the device a decade ago, Apple has sold more than 1.2 billion iPhones.
Facebook reached the mark of 2 billion users per month in June. Together, both companies have shaped an entire generation of young people tethered to their devices.
The three Lee teens – Jake, age 18; Sydney, 16; and Maddi, 13 – all have iPhones. They consume a steady diet of social media. Selfies, hashtags, emojis, YouTube celebrities, and memes fill their days and nights. They’re admitted jocks – water polo and soccer players – so they have only so much time to stare at screens. But it’s still a big part of their lives.
Maddi sticks mostly to Instagram, the photo-sharing app. “Facebook is for old people,” she says. Sydney has 574 Instagram followers but says she’s not as obsessed as many of her friends. She prefers Snapchat, the popular image messaging app,…