There is a famous quote from French existentialist philosopher Jean-Paul Sartre: “Hell is other people.” While some may agree with that sentiment and crave solitude, there’s a lot of evidence that people are drawn to each other. We form friendships, sports teams, knitting circles and complex societies, unlike any other species on Earth.

Nicholas Christakis, a doctor, sociologist, and author of “Blueprint: The Evolutionary Origins of a Good Society,” has spent years trying to understand why people often feel compelled to connect to - and help - each other. The answer he arrived at was that, although humans are capable of a lot of bad things, it turns out being good has long been coded into our biology