We've all experienced it: the wrinkles that form on our fingertips after prolonged exposure to water. While they may resemble temporary 'granny hands,' these changes serve a practical purpose. Neurobiologist Mark Changizi, from 2AI Labs in Utah, has shown they likely enhance grip.
Like Tire Treads on Wet Roads
Research from 2AI Labs reveals that water-induced wrinkles have an evolutionary advantage. Changizi compares them to the grooves on car tires, which prevent slipping in rain or sleet. Similarly, when water coats the smooth surfaces of our fingertips, grip weakens. In response, our fingers develop their own treads: wrinkles.
The Spark of Insight "The idea came from my student Romann Weber," Changizi shared with The Huffington Post. "During a discussion, he wondered if wrinkles on wet hands function like car tire grooves. I thought it was brilliant."
The team rigorously analyzed photos of 28 water-wrinkled human fingers, confirming a consistent pattern.
Vertical Drainage Channels
The wrinkles consistently formed vertical channels running from the fingertip downward, efficiently channeling away water for better traction.
Controlled by the Nervous System
Prior studies indicate that individuals with nerve damage in their hands or feet don't develop these wrinkles in water—such as during a bath. This suggests the nervous system triggers the response, underscoring its evolutionary role.
Changizi plans further experiments to confirm improved wet grip. Preliminary evidence from photos of rain-soaked monkeys shows they too develop fingertip wrinkles while climbing.
The findings were published in the journal Brain, Behavior and Evolution.
