For several years now we have lived a large part of our lives on social networks. I would say we devote almost as much attention to them as to our most intimate emotional surroundings. Almost all of us are hooked—nearly addicted. These networks seem designed to trigger some reward system in the brain, releasing a quick shot of dopamine each time we receive the tribe’s approval. It’s a flash of instant gratification that urges us to keep typing, and at the same time keeps us staring at the screen when that approval doesn’t come. That’s on one side.