When MPR News host Kerri Miller travels to small towns around Minnesota for her Rural Voice series, she hears over and over again about the crisis of loneliness and social isolation. People say that even in communities where they know everyone, it’s easy to feel adrift.

It’s no surprise to neuroscientist Ben Rein, who studies the inner workings of the human brain. He writes in his new book that our brains have been shaped for social contact, both inside and out. When we don’t get enough social interaction, our bodies are stressed. And in our post-COVID, screen-obsessed world, a good chunk of the population is suffering from too much alone time.

Rein joins Miller on this week’s Big Books and Bold Ideas to talk about why friendships are as important to health as how often you exercise and how much you sleep, and why online relationships aren’t enough for a brain that’s evolved to expect face-to-face.