Bumping fists instead of shaking hands could reduce the spread of infectious diseases, researchers have suggested.
Fist bumps are more hygienic as a result of its speed and smaller contact area, academics at Aberystwth University said.
Researchers used thick rubber gloves and a layer of the bacteria E.coli before exchanging handshakes, high fives and fist bumps to determine which greeting was the cleanest.
High doses of the bug were transferred during a handshake, but that was reduced by more than half during a high five and 90% when bumping fists.
"People rarely think about the health implications of shaking hands. But if the general public could be encouraged to fist bump, there is a genuine potential to reduce the spread of infectious diseases," Dr Dave Whitworth, senior lecturer at Aberystwyth University, said.