Hugh Pickens writes "The BBC reports that scientists say they have disproved the theory that fingerprints improve grip by increasing friction between people's hands and the surface they are holding. Dr Roland Ennos designed a machine which enabled him to measure the amount of friction generated by a fingerprint when it was in contact with the acrylic glass. Ennos expected the amount of friction to increase in proportion to the strength at which the acrylic glass was pushed against the finger, however the results showed that friction levels increased by a much smaller amount than had been anticipated debunking the hypothesis that fingerprints provide an improved grip. Ennos believes that fingerprints may have evolved to grip onto rough surfaces, like tree bark; the ridges may allow our skin to stretch and deform more easily, protecting it from damage; or they may allow water trapped between our finger pads and the surface to drain away and improve surface contact in wet conditions. Other researchers have suggested that the ridges could increase our fingerpads' touch sensitivity. Dr Jon Barnes, a biomechanics expert at the University of Glasgow, is sanguine about the results. "It's always nice to knock down an urban myth with good data.""