Body language experts are on the news a lot these days. Because it’s an election season, they’re asked to interpret the subtle, nonverbal cues that give insight into a political candidate’s feelings.

One particular observation got my attention recently, because I had never heard anyone put a name to certain gestures a speaker makes, like clutching hands together, putting hands to the face, or massaging an arm. Body language experts call these “comfort gestures.”

Such actions serve to soot...