Empathy is a superpower for connecting and communicating with others, but it can be surprisingly fragile. A bad mood, an aching back, or an otherwise preoccupied mind can easily close us off even to the people we’re closest to, let alone to colleagues or strangers on the daily commute. Noticing this, Alan Alda wondered what exercises could help bulk up the “empathy muscle” or keep his “empathy thermometer” hot regardless of shifting circumstances. An exercise he invented became the focus of...