The real reason for pruney fingers

UPDATE: 2012-01-09 Researchers at my alma mater, Newcastle University, have today published experimental evidence that supports Changizi’s theory. According to a report from Nature news: “Laboratory tests [by Tom Smulders et al published in Biol Lett] confirmed a theory that wrinkly fingers improve our grip on wet or submerged objects, working to channel away the water like the rain treads in car tyres.”

The real reason for pruney fingers – Sit in a bath too long and your fingers will wrinkle up. Everyone from 5 to 95 knows that. The scientific explanation was always that the skin absorbs water and the underlying layer buckles. That’s as may be, but writing in Nature News, Ed Yong explains an explanation from Mark Changizi and colleagues that suggests pruney fingers have an evolutionary advantage in that they allow us to get a grip when we’ve been in the water.

Changizi, an evolutionary neurobiologist at 2AI Labs in Boise, Idaho, and his colleagues think that the formation of wrinkles on the pads of our fingers when we swim or bathe act like tyre treads in wet conditions expelling water when conditions are slippery. It’s possible, just don’t rely on a theory to save your glass if you enjoy long soaks champagne in hand.

3 thoughts on “The real reason for pruney fingers”

  1. Thank you so much for posting this. Everytime I take a bath I tell myself “I’m going to google why my fingers prune, I’m sure there’s a reason” but by the time I’m dry and at a computer again I always forget.
    So thanks!

  2. Ah, but you don’t need such big ridges to grip something dry. You have your fingerprints and a little sweat to assist at that level. In the wet a prune-like surface would not only help disperse water but the spongier texture would allow a much greater surface area to grip wet rock say…but more to the point, we may have adapted to get wrinkly fingers because of an environmental pressure that is no longer apparent. Lots of characteristics evolve that are vestigial and merely point to some condition that led to greater reproductive success in the past and don’t necessarily help us now to the same degree that they did way back when. I was never convinced by the aquatic ape theory but existing at water margins might have benefited from the prune finger response…

  3. As extra grip would always be useful, why have it only in the bath? I think the evolutionary reasoning is faulty, and getting a grip on the correct answer is far more slippery.

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