A Moment of Science

Wrinkles Reconsidered – Why Your Fingers And Toes Wrinkle When Wet

A Moment Of Science revisits the science of hands and feet that wrinkle when wet.

Four fingers, wrinkled from water immersion

Photo: Brenderous (Flickr)

There may be a purpose for fingers and toes to wrinkle when wet.

Have you noticed how wrinkly your fingers and toes become if they are immersed in water. Perhaps you have noticed this in a swimming pool, the bath, or even in a heavy rain. Why does this happen?

Water Absorption Not The Answer

For a long time scientists thought that simple water absorption was the cause of your misshapen digits, but this theory doesn’t hold water. If wrinkly skin was the result of water absorption, wouldn’t our whole bodies become wrinkled when immersed in water?

For awhile, it was believed that the presence of the tough protein keratin (that is, your finger and toenails) caused our fingers and toes to swell unevenly when they absorbed water, resulting in wrinkles. You may have even heard this explanation on A Moment Of Science.

However, this too is a problematic theory because scientists have shown that cutting the nerves to our digits prevents these wrinkles from forming. If the cause was water absorption, the nervous system would probably not be involved.

A Better Grip

New research suggests that the wrinkles have a purpose, and this purpose is to allow us to get a better grip when conditions are slippery.

Just like tire treads draw water away from the surfaces of the tire that grip the road, the wrinkles in our toes and fingers channel water away from the surfaces of our hands and feet that we use to get a grip on things.

Read More:

Really? The Claim: Fingers Wrinkle Because of Water Absorption (The New York Times)

Why Do Fingers Wrinkle When They Get Wet? (NPR)

Erin Sweany

Erin is a graduate student at Indiana University studying early English medical texts. Erin has studied both science and literature throughout her academic career. She loves science for what it tells us about our world and literature for what it tells us about our culture. Erin combines these interests in her scholarship and writing as much as possible.

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