Why do fingers become pruney? - Mark Changizi

TL;DR

Pruney fingers act as rain treads, enhancing grip in wet conditions.

Transcript

Transcriber: Andrea McDonough Reviewer: Jessica Ruby There are all sorts of things that happen every day that might make you ask, "Why? Why do we drive on a parkway and park on a driveway? Why does my hair get frizzy when it's humid? And why do my fingers get all pruney when they're wet?" Often we simply can't know the answers to these questions. B... Read More

Key Insights

• 🚃 Pruney fingers may have evolved as a way to enhance grip in wet conditions, similar to rain treads on car tires.
• 🥺 Observations of nerve-damaged patients led to the discovery of pruney fingers' functional purpose.
• 🖐️ Pruney fingers display a network of divides and ridges resembling river drainage systems on convex promontories.
• 🖐️ Behavioral experiments confirm that pruney fingers indeed improve grip in wet conditions, aiding in tasks like grasping wet objects.
• 🖐️ Pruney fingers may have developed in primates to compensate for the loss of claws and deal with grip challenges in wet forest habitats.
• 🥺 Studying similarities between unrelated systems, like wet fingers and rain treads, can lead to new insights and ideas in science.
• 🖐️ Understanding the science behind pruney fingers highlights the complexity and adaptive nature of human biology.

Questions & Answers

Q: Why do some people get pruney fingers in water while others don't?

Pruney fingers are believed to act as rain treads, channeling out water to enhance grip in wet conditions, similar to car tires on rainy roads.

Q: How do pruney fingers help in gripping wet objects?

Behavioral experiments have shown that pruney fingers actually enhance grip in wet conditions, allowing individuals to perform tasks like grasping wet marbles more efficiently.

Q: What observation led to the idea of pruney fingers functioning like rain treads?

Doctors noticed that patients with nerve damage didn't get pruney fingers, suggesting a function beyond mere skin wrinkle formation in water.

Q: How do pruney fingers resemble river networks?

Pruney fingers show a tree network of divides or ridges, similar to river drainage patterns on convex promontories, channeling water effectively during gripping.

Summary & Key Takeaways

• In the 1930s, doctors observed that patients with nerve damage didn't get pruney fingers like others in water.

• Pruney fingers may function like rain treads on car tires, channeling out water for better grip.

• Behavioral experiments show pruney fingers indeed enhance grip in wet conditions.