Viewers watching the Summer Olympics in Rio have surely wondered why star athletes bite down on their gold, silver or bronze medals once they’re hung around their necks.

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Michael Phelps did it when he won.

(Photo: Getty Images)
Simone Biles did, too.

(Photo: Getty Images)
Even Amy Van Dyken in 1996 did it.

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No, it’s not to see if they’re made of real gold, either.
Olympic medals are actually just 1.34 percent gold and the rest of it is sterling silver — and even most of that is recycled.

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They bite them mainly because the photographers tell them to do so.
David Wallechinsky, the president of the International Society of Olympic Historians and co-author of “The Complete Book of the Olympics,” explained why in 2012.
“It’s become an obsession with the photographers,” Wallechinsky said. “I think they look at it as an iconic shot, as something that you can probably sell. I don’t think it’s something the athletes would probably do on their own.”
Wallechinsky added that it’s especially popular for swimmers.

(Photo: Getty Images)