Fingerprints enhance the sense of touch.

Here is a curious factoid, or near factoid. From Miller's review of Scheibert et al.:

After a series of experiments with a sensor designed to mimic a small patch of skin on a human fingertip, Alexis Prevost, Georges Debrégeas, and their colleagues at the École Normale Supérieure in Paris conclude that fingerprints likely enhance the perception of texture by increasing vibrations in the skin as fingers rub across a textured surface. In particular, fingerprints amplify vibrations in the frequency range that best stimulates Pacinian corpuscles, mechanoreceptors in the skin important for texture perception...The ridges made the vibrations picked up by the underlying sensor up to 100 times stronger...The new results leave open why human fingerprints are arranged in elliptical swirls....the amplification effect was strongest when the textured glass slid perpendicular to the ridges, so it's possible that the loops ensure that no matter how the fingers move, some ridges are always optimally oriented.