Keep your hands in water and the skin of your fingertips wrinkles. The effect is striking and we know little about why it happens. One proposal is that the wrinkles channel water away from the contact surface, so a wet object can be grasped more readily, which is a claim about force rather than about appearance.
They cut the force a wet grip needs. Across three conditions, dry fingers, wrinkly fingers, and fingers , the wrinkly ones reduced the needed for a wet object. The force came into line with what a dry object needs. Grip efficiency in watery environments is the possible .
For most people, immersing their hands in water leads to wrinkling of the skin of the fingertips. The phenomenon is very striking, and we know little about why it occurs.
One proposal is mechanical. The wrinkles act to distribute water away from the contact surfaces of the fingertip, which would mean wet objects can be grasped more readily. That is a prediction you can put on a force sensor.
The study examined the coordination between grip force and , with participants using dry fingers, wrinkly fingers, or fingers that were wet but not wrinkly.
Wrinkly fingers reduced the grip force needed to hold a wet object, bringing that force in line with what is needed for a dry one. The author’s reading is that enhancing grip force efficiency in watery environments is a possible adaptive reason for the development of wrinkly fingers.
wat. Wrinkly fingers held a wet object with the force a dry hand needs.
wat wat
A body change everybody has noticed turns out to be testable, by measuring what the hand has to do rather than what it looks like.
How do we know?
Davis measured the coordination between the grip force participants used to hold an object and the load force they exerted on it, across the three finger conditions.
What is still unknown
Showing a functional benefit is not the same as showing the trait evolved for it, which is why the paper says possible adaptive reason.
Learn something?
Where to next
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