A nice firm handshake has long been a mark of good manners and elevated social skills. It is also a very germy way to greet your fellow humans, much worse than a couple of more casual alternatives, a new study shows.
"A short, sweet fist bump will transmit the least bacteria," and even a high-five is better than a traditional shake, says David Whitworth, a senior lecturer in biochemistry at Aberystwyth University-Ceredigion in the United Kingdom.
Whitworth and a colleague systematically tested the three greetings for a study published Monday in the American Journal of Infection Control.
For the experiment, one of them repeatedly dipped a gloved hand into a container loaded with a not-too-dangerous strain of E. coli bacteria. ("Not-too-dangerous strain of E-coli"! That's reassuring.) The dirty-gloved scientist let the film dry, then shook, fist-bumped or high-fived the other person's clean, gloved hand.
Result: The shakes transmitted about 10 times more bacteria than the fist bumps and about two times more than the high fives. (Howie Mandel's mysophobia suddenly seems a little less untenable.)
Since we don't go around dipping our hands in vats of bacteria, the experiment does not perfectly mimic real life – in which different areas of the hand carry different amounts of bacteria, for one thing. It does provide some new ammunition for those who would like to ban handshaking in hospitals and other places (at Mass) where germs are a particular concern.
Whitworth says it also provides an especially good alternative, the fist bump. "You can't really imagine a world where people don't greet each other physically," he says. "It seems to be a basic human need."