In five or ten years could social coherence monitoring be as routine an event for the device-devoted as texting is today? So far, there’s no app for it. Social coherence is a concept, but too complex to have made it to the popular market. Still, I find the possibility mesmerizing—that the physiologies of two people (or seven!) could synchronize—not just their thoughts, but their heart beats, their breathing rates, their hormones. Why not?