Buzz
You may have observed that your fingers and toes appear wrinkled after being immersed in water for some time. This phenomenon, often called 'prune hands,' makes your skin look like a shriveled prune (a dried plum). The wrinkles are a result of the blood vessels beneath your skin narrowing, which is controlled by your autonomic (Aw-toe-NAW-mick) nervous system. This system manages essential functions like breathing and heartbeat without your conscious effort.
These wrinkles seem to enhance your grip, preventing slips! Have you ever noticed the grooves on the bottom of your shoes? Those are treads, which are also found on car and bus tires. When water fills these grooves, it gets pushed out. Your skin works similarly—water drains through the grooves in your wrinkled hands, improving your ability to hold onto things. An experiment demonstrated this: people with wet, wrinkled hands picked up wet marbles faster than dry ones.
Some scientists now believe that humans evolved (Ee-VAWLVD) this reaction over time. The ability to grip wet objects may have helped our ancestors survive. Imagine trying to grab food in a wet environment, like a river, ocean, or rainforest—wrinkled fingers would give you a better hold. If you were climbing a wet tree, the wrinkling could prevent you from slipping. Wrinkled toes could provide a better grip in slippery or muddy conditions when you're barefoot.
Interested in learning more about the marble experiment? Check out this video from SciShow.
