If you’ve ever been on a subway or public bus, you know the rules. Don’t make eye contact, stay as far away from other people as the space allows, and for the love of God, don’t talk to anyone. But what if the rules are wrong?

The behavioral scientists Nicholas Epley and Juliana Schroeder approached commuters in a Chicago area train station and asked them to break the rules. In return for a $5 Starbucks gift card, these commuters agreed to participate in a simple experiment during their train ride. One group was asked to talk to the stranger who sat down next to them on the train that morning. Other people were told to follow standard commuter norms, keeping to themselves. By the end of the train ride, commuters who talked to a stranger reported having a more positive experience than those who had sat in solitude.

If the idea of talking to a random seatmate fills you with dread, you’re not alone. When Dr. Epley and Ms. Schroeder asked other people in the same train station to predict how they would feel after talking to a stranger, the commuters thought their ride would be more pleasant if they sat on their own.

Why are these commuters’ predictions and their experiences so at odds? Most people imagined it would be difficult to start a conversation. They estimated that fewer than half of their fellow commuters would want to talk to them. But in fact, not a single person reported having been snubbed. And the conversations were consistently pleasant.