Who Made Fist Bumps “Cool”?

The familiar knocking of knuckles spreads only one-twentieth the amount of bacteria that a handshake does, researchers report. That's better than a high-five, which still passes along less than half the amount as a handshake.
So fist bumps — popularized by Barack Obama and others — seem to be the wisest greeting, especially during cold and flu season, said researcher David Whitworth of Aberystwyth University in Wales.
Photo via Associated Press