WHY do our fingers do prune impressions when soaked? It could be an adaptation that gives us better grip underwater.
Fingers and toes wrinkle in water after about 5 minutes due to the constriction of blood vessels. This reduction in volume pulls the skin inward, but as the skin's surface area cannot change, it wrinkles. A study in 2011 showed that wrinkles form a pattern of channels that divert water away from the fingertip – akin to rain treads on tyres. The team thought that this could aid grip.
To find out, Tom Smulders and his team at Newcastle University, UK, timed people as they transferred wet or dry objects from one box to another with and without wrinkled fingers.
With wrinkles, wet objects were transferred about 12 per cent faster than with unwrinkled fingers. The time it took to transfer dry objects was the same regardless of wrinkles.
So why aren't our digits always prune-like? "With wrinkles, less of your skin surface touches the object, so there may be issues of sensitivity," Smulders suggests.
Journal reference: Royal Society Biology Letters, DOI: 10.1098/rsbl.2012.0999.
If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.
All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.
If you are having a technical problem posting a comment, please contact technical support.
Pruney fingers give us better grip underwater
This article
Pruney fingers give us better grip underwater
can be opened in url
http://newsearful.blogspot.com/2013/01/pruney-fingers-give-us-better-grip.html
Pruney fingers give us better grip underwater
