Nicholas Barnes, 11, has always been a social kid. Before the pandemic, his busy schedule included school, Cub Scouts, basketball practice, church, and playing with friends in his Winter Park, Florida, neighborhood.

Now the only people Nicholas sees in person are his parents and two older brothers. But even before his school started online, his interactions with others had become extremely limited. At a small, family-only birthday party for his older brother in July, he had trouble describing his feelings at the get-together. “I enjoyed seeing my people enjoy being around each other,” he said. It’s a complex feeling he never thought about before. But it’s also a feeling that’s deeply rooted in our genes and helps explain why the social