Similarity—the genuine, not the manufactured, variety—is a key form of human connection.

Anyone who sells—whether they’re trying to convince customers to make a purchase or colleagues to make a change—must contend with wave after wave of rebuffs, refusals, and repudiations.

How to stay afloat amid that ocean of rejection is the second essential quality in moving others. I call this quality “buoyancy.” Hall exemplifies it. Recent social science explains it. And if you understand buoyancy’s three components—which apply before, during, and after any effort to move others—you can use it effectively in your own life.

Sales and theater have much in common. Both take guts. Salespeople pick up the phone and call strangers; actors walk onto the stage in front of them.

In most circumstances that involve moving others, we have several ways to accomplish a task, most of which can make our partners look good in the process.

But emotionally intelligent signage goes deeper. It achieves those same ends by enlisting the principles of “make it personal” and “make it purposeful.” It tries to move others by expressing empathy with the person viewing the sign (that’s the personal part)...