Why do fingers get pruney in water?

Answer: Nerves trigger better grip reflex

Dead skin cells expand randomly — Wrong. Pruney fingers aren't random dead cell expansion—it's a controlled nervous system response. Blood vessels constrict under the skin in a specific pattern that improves grip on wet objects.

Nerves trigger better grip reflex ✓ — Correct! Pruney fingers are caused by blood vessels constricting under the skin in response to prolonged water exposure. This creates wrinkles that actually improve grip on wet objects—an evolutionary advantage for handling things in water or rain.

Soap dissolves protective oils — Wrong. Soap isn't necessary for pruney fingers—it happens in plain water too. The wrinkling is a nerve-controlled response.