The danger is all too real: One weekend, you run into a work colleague at a bar in a city that is not the city you both work in. Mike? In Baltimore? In the same dive bar as you? Crazy!

Because you and Mike have never said more than five words to each other, you reach out your right arm to shake his hand or to wave at him. But Mike, overcome by the serendipity and coincidence of your meeting, stretches out his arms Christ the Redeemer-like for a big hug.

Suddenly conscious that you should upgrade your greeting, you find that your arms, animated by forces unknown, are splitting the difference between a handshake and a hug. Your right hand extends forward at waist level for a clasp, but your left hand, strangely, starts to claw at Mike’s shoulder like the involuntary spasms of a dying raptor. Meanwhile Mike presses on with his hug, casting over the entire proceedings the appearance of a fumbled knifing.

It’s huggy out there. It requires ever less and less acquaintance with someone, it seems, to be the recipient of a well-meaning embrace. Among young people and certain gregarious and gestural adults, a hug is the default greeting.