In a soon-to-be published study from the American Journal of Infection Control, researchers at the UK's Aberystwyth University found the fist bump transferred 90 percent fewer bacteria than a regular, old handshake.
Their methods for reaching this conclusion were rather interesting: the scientists used rubber gloves and spread them with a thick layer of E. coli bacteria. They then exchanged fist bumps, hand shakes, and high fives with researchers who were wearing clean rubber gloves, randomly varying the intensity and duration of the greetings.
Afterward, the researchers set the gloves in a solution that allowed them to count how many bacteria were transferred to the clean gloves.
Their finding? The handshake was the worst offender when it came to spreading germs.
The high five transferred half the bacteria of a handshake, while the fist bump transferred 90 percent fewer germs than the standard greeting. The longer the exchange lasted and the more intense the grip, researchers found, the more strongly associated with microbe swapping.
One of the study authors, Dr. Dave Whitworth, a senior lecturer at Aberystwyth University, had this message for the public: "People rarely think about the health implications of shaking hands. If the general public could be encouraged to fist-bump, there is genuine potential to reduce the spread of infectious diseases."
There's even a "Stop Handshaking" movement online, which encourages acolytes to "tell others you don't shake hands" by wearing a "no handshake" button. People can "turn down a handshake without saying a word," the website reads.
These sentiments are rooted in the science of hand hygiene. Public health researchers have long known that clean hands can literally save lives by reducing the spread of dangerous pathogens.
According to the Centers for Disease Control and Prevention, hand-washing can reduce the number of the people who get sick with diarrhea and respiratory illnesses by up to 50 percent.
If the handshake originated as a gesture of peace—to show your opponent that you were not holding weapons—then the fist bump may soon emerge as the best way to demonstrate you're serious about not spreading microbes.