Driving together reveals how people handle uncertainty when neither can leave the conversation easily.

A car is a small room that keeps moving whether or not anyone in it is comfortable. Nobody can walk out, the route is unresolved, and both people are out of control, so what normally stays hidden shows: irritability, blame, the urge to be right about the turning. Nobody designed it as a test, and it still tells you something. How a person behaves when they cannot leave a situation is worth knowing early.

On the next long drive together, watch your own reaction to being lost more than your companion’s. Say what you need out loud, since guessing in a moving car goes badly for both of you.