Okay, okay, I know this is isn't exactly health-related - but after drying off the small, pruney fingers of my freshly bathed daughters about a thousand times, I just couldn't resist writing about a new theory for why wrinkles appear on wet fingers. In a new Brain, Behavior and Evolution paper, researchers hypothesize that the wrinkles help provide us with better grip in slipper conditions. From Nature News:
The hypothesis, from Mark Changizi, an evolutionary neurobiologist at 2AI Labs in Boise, Idaho, and his colleagues goes against the common belief that fingers turn prune-like simply because they absorb water.
Changizi thinks that the wrinkles act like rain treads on tyres. They create channels that allow water to drain away as we press our fingertips on to wet surfaces. This allows the fingers to make greater contact with a wet surface, giving them a better grip.
"I stumbled upon these nearly century-old papers and they immediately suggested to me that pruney fingers are functional," says Changizi. "I discussed the mystery with my student Romann Weber, who said, 'Could they be rain treads?' 'Brilliant!' was my reply."