Prune Hands Explained

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U.K. researchers might have figured out one of the most enduring questions about human anatomy: Why do we get prune hands when sitting in the tub?

A team at Newcastle University has concluded through experiments and testing that wrinkled fingers make it easier for humans to pick up wet, slippery objects. The researchers suggest in reports published in Britain's Royal Society journal Biology Letters that as our distant ancestors searched for food in wet land and streams, the creases evolved.

"Upon continued submersion in water, the glabrous skin on human hands and feet forms wrinkles. The formation of these wrinkles is known to be an active process, controlled by the autonomic nervous system," the research's abstract states. "Such an active control suggests that these wrinkles may have an important function, but this function has not been clear."

In their studies, the researchers showed that submerged objects are handled quicker with wrinkled fingers than with unwrinkled fingers, and that wrinkles make no difference when trying to manipulate dry objects.

They believe that the research supports their hypothesis that wrinkles might be an adaptation for handling objects in wet conditions.