Pruney Fingers: A Gripping Story
In this week’s special "Summer Science" edition of It’s Okay To Be Smart (which you have already watched, right?!), we took a quick look at why our fingers wrinkle up when we’ve been in the water for a while.
While scientists used to believe this odd occurrence was just our skin getting soggy, but that explanation doesn’t hold water. Besides, if that was the case, why does this only happen in our fingers?
Modern science has added a wrinkle to this tale. Biologists noticed that if the nerves that fed into the fingers were damaged or severed, then the skin no longer got pruney. This means that some sort of active process is driving the prunification, a very (un)conscious decision on the part of our brain and body.
Could it be that pruney fingers are an adaptation? An odd phenomenon that actually gives us an advantage in wet conditions? It’s still not known for sure, but judging by the work of neuroscientist Mark Changizi it seems likely.
In the above video from TED-Ed, Changizi explains how, if we predict that wrinkly fingers act like dermal tire treads, we should see the same patterns in our skin that we see in river drainage networks. It turns out that is exactly what we see!
Other scientists went on to test whether those wrinkles gave people better grip under wet conditions. Want to know what they found? Watch the video and soak up some awesome science.
If you haven’t watched this week’s summer-themed OKTBS, you can check it out below :)
*I should note that not everyone agrees with the rain tread hypothesis for pruney fingers, but it’s the best explanation we have so far