"Closed-fist high-fives." In 2008, that's how a wide-eyed New York Times article described the confounding gesture Barack Obama was sharing with members of the media on the campaign trail, and later, famously, his wife.

The world, though, had for years been calling this a fist bump. (Or, Wikipedia offers: "dap, pound, fist pound, bro fist, spudding, fo' knucks, box, bust, pound dogg, props, bones, or respect knuckles.")

The origin of the fist bump is a subject of concentrated but heated disagreement. Many narratives center on athletics, with historians of various sports claiming the fist bump as their creation. Athletes wanted to minimize the risk of dislocating a finger in a passing or celebratory handshake. The more aggressive, less formal fist bump was better suited to the cause, and it continues to evoke machismo and bro-ness.

It is being re-appropriated gradually.

Rejecting the patriarchy aside, the fist bump has science behind it—reason to hasten its integration as a formal gesture of gender-neutral respect. The handshake, its alternative, is unsanitary. The handshake is outdated in most places, born of a time when we might all be expected to be concealing sabers. It would make more sense for us to casually intertwine almost any other part of our bodies with those of strangers, lips and genitals the notable exceptions.

In research published recently by The Journal of Hospital Infection, surgeons at the West Virginia University set out to see if they can reduce the spread of infection by fist bumping instead of shaking hands.