Turns out those pruney fingers you get when you’ve showered for too long aren’t just some by-product of water-absorption. From Forbes:
[W]hy would water absorption lead to wrinkles with that signature shape? And why would water absorption lead to wrinkles on the finger tips but not all the other spots on the body? And why would water absorption lead to wrinkles at all, given that water absorption should generally lead to swelling and consequently taut skin? No, water absorption can’t explain it. […]
[I]n fact, it has been known since the 1930s that nerve damage to a finger abolishes the pruney response. Pruney fingers are neuronally modulated. That’s even further reason to suspect that our prunes are adaptive.