The handshake is an important way that many people communicate nonverbally. It’s a standard gesture when we say hello, goodbye, and make an agreement. We’ve been doing it for millennia. But hands carry germs that can spread infections to others. And some of these infections can be very serious, including those that can’t be killed by standard antibiotics. Is it time to consider changing the tradition of shaking hands? Two researchers from Aberystwyth University in Wales make the case that handshaking exchanges a lot more germs than a modern alternative, the fist bump. In a nifty experiment, they showed that shaking hands transmitted 2 times more bacteria than high fives, and 10 times more bacteria than bumping fists. Their results are published in the August 2014 issue of the American Journal of Infection Control.