Why exactly do we have fingerprints? What do you think? What is their function?

Never thought about this before. My guess was that the ridges make us more sensitive to touch.

I heard an interview on the radio with a researcher who works on hands, claws etc. He has just published a paper that says that fingerprints do not improve our grip. The reverse is true, there is less friction so there is less grip.

In the experiments a graduate student had his fingers and thumbs attached to a machine that pressed his hand and dragged it against a Perspex sheet, and the amount of friction was measured. As the poor graduate student’s hand was pressed harder the level of friction on the skin did not increase as fast as expected.

Thinking about it, this makes sense. Having ridges on our fingers means that the whole surface is not in contact with something, but just the smaller area of the ridges.

The researcher suggested that the ridges protect our fingers from damage by not gripping so well. As he mentioned, areas that have a strong ridge pattern are more resistant to blisters than the flatter areas. For instance when doing things that involve friction and the skin on our hands,we are less likely to get blisters on our finger tips than smoother areas of the hand.

Other theories of why we have fingerprints are the sensitivity to touch, and something to do with channeling water away, so when are hands are wet we don’t lose so much grip.

Sometimes I find it amazing what we don’t know. Since skin is obvious and easily accessible for study, you would think we would know pretty much everything about it.

photo credit: Steve & Jemma Copley

[tags]fingerprint, grip, friction, skin[/tags]