Why We Get Prune Fingers

More

Evolution explains: wrinkled fingertips give us a better grip on wet things. Like built-in traction gloves.

prune giners 615.jpg.jpg
quinn.anya/flickr

Here's a dinner party fact. If you were to soak a severed hand in a bucket of water, it wouldn't develop prune fingers. That's right, because finger prune-wrinkling is a nervous system response, not just some osmotic result of our skin absorbing water like a wet potato. 

We've known that for a long time, but until this week, we didn't know exactly why that autonomic response existed. 

meritbadgeman.jpgsteve.garner32/flickr; superfantastic/Flickr

The 2011 journal article "Are wet-induced wrinkled fingers primate rain treads?" suggested that prune fingers work like car tires. The wrinkles channel water off of our fingers, so we get better traction on things we want to hold. But that was just their theory from the way it looks; they didn't actually test that it worked.

This week, research in the journal Biology Letters, proved that people with water-wrinkled fingers were indeed faster at picking up wet marbles.

So, as evolution would have it, our ancestors who were not as good at picking up marbles were less likely to be chosen as suitable mates and pass along their genes. Or, actually, the ones who weren't as good at hand fishing and clam digging and those sorts of things after their hands were all wet and slippery; they wouldn't thrive and reproduce. The prune-fingered people, meanwhile, flourished and feasted and were the eminently desirable.

Our toes wrinkle in water, too; don't forget. (Did you forget about your toes?) The researchers deduce that toe wrinkling is, similarly, to help us get traction when we're walking/running on wet surfaces. Which is interesting, because we're still not that good at it.

Jump to comments
Presented by

James Hamblin, MD, is a senior editor at The AtlanticHe is the host of If Our Bodies Could Talk.

 
 
More

Get Today's Top Stories in Your Inbox (preview)

The Ghost Trains of America

Can a band of locomotive experts save vintage railcars from ruin?


Elsewhere on the web

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register. blog comments powered by Disqus

Video

Why Did I Study Physics?

Using hand-drawn cartoons to explain an academic passion

Video

What If Emoji Lived Among Us?

A whimsical ad imagines what life would be like if emoji were real.

Video

Living Alone on a Sailboat

"If you think I'm a dirtbag, then you don't understand the lifestyle."

Video

How Is Social Media Changing Journalism?

How new platforms are transforming radio, TV, print, and digital

Video

The Place Where Silent Movies Sing

How an antique, wind-powered pipe organ brings films to life

Feature

The Future of Iced Coffee

Are artisan businesses like Blue Bottle doomed to fail when they go mainstream?

Writers

Up
Down

More in Health

Just In