Why do our fingers wrinkle when wet?

Hint: Think "car tires"

Wrinkly digits work similarly to tire treads.
(Image credit: ThinkStock/Stockbyte)

Ready to have your mind blown? For a long time, scientists thought that our fingers wrinkled underwater because of osmosis — meaning the skin's cells absorbed water, causing our fingertips to shrivel up. But new research suggests another explanation for why our digits suddenly morph into raisins when wet: The wrinkles help us to better grip objects underwater, in much the same way tire treads help cars stay on the road.

Scientists were tipped off in recent years when they discovered that severed fingers didn't wrinkle underwater. This suggested the wrinkling mechanism was controlled by the nervous system, and was therefore some kind of evolutionary response.

A study in 2011 showed that the wrinkles indeed functioned like rain treads, in that the grooves helped divert water away from the fingertips. For this study, researcher Tom Smulder and his team at Newcastle University in the U.K. asked subjects to move wet and dry objects from one box to another with and without shriveled fingers. Unsurprisingly, people with wrinkled hands transferred objects 12 percent faster than those with smooth digits.

Subscribe to The Week

Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

SUBSCRIBE & SAVE
https://cdn.mos.cms.futurecdn.net/flexiimages/jacafc5zvs1692883516.jpg

Sign up for The Week's Free Newsletters

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

Sign up

As to why our fingers aren't wrinkled at all times, Smulders says it may have something to do with maintaining our fingertips' sensitivity. Amazing stuff. The human body, ladies and gentlemen.

To continue reading this article...
Continue reading this article and get limited website access each month.
Get unlimited website access, exclusive newsletters plus much more.
Cancel or pause at any time.
Already a subscriber to The Week?
Not sure which email you used for your subscription? Contact us
Chris Gayomali is the science and technology editor for TheWeek.com. Previously, he was a tech reporter at TIME. His work has also appeared in Men's Journal, Esquire, and The Atlantic, among other places. Follow him on Twitter and Facebook.