Wrinkly fingers improve grip on wet objects

The reason why we get wrinkled fingers and toes after spending too long in the bath may be down to our ancestors.

Scientists believe that the wrinkling of our digits after they are submerged in water for long time may have helped our ancestors handle objects underwater. Tom Smulders and his team at the University of Newcastle, UK timed volunteers handling wet and dry marbles. They found that volunteers with wrinkled fingers handled the wet marbles 12% faster than their counterparts with unwrinkled fingers. There was no difference between both sets when handling the dry objects.

“We have shown that wrinkled fingers give a better grip in wet conditions – it could be working like treads on your car tyres which allow more of the tyre to be in contact with the road and gives you a better grip,” says Smulders.

“Going back in time this wrinkling of our fingers in wet conditions could have helped with gathering food from wet vegetation or streams.

“And as we see the effect in our toes too, this may have been an advantage as it may have meant our ancestors were able to get a better footing in the rain.”

Their findings shed new light on a process that has long baffled scientists. It used to be thought that the swelling of our fingers happened when water passed into the outer layers of our skin. However, we now know that the wrinkling is an active process, controlled by our nervous system; which suggests that it serves a particular purpose or function.

“This raises the question of why we don’t have permanently wrinkled fingers and we’d like to examine this further,” adds Smulders.

“Our initial thoughts are that this could diminish the sensitivity in our fingertips or could increase the risk of damage through catching on objects.”

The study is published in the journal Biology Letters.