Why Do We Have Fingerprints? What Science Says About Fingertip Grip
Fingerprints are best known for identifying people, but they also affect how your fingertips touch things. A 2013 review in the Journal of the Royal Society Interface by Adams and colleagues looks at the physics.
What the review looks at
The review is about friction in the contact zone of the finger pad, which matters for both grip and the sense of touch. It says friction plays a crucial role in grip, while its exact contribution to feeling textures as a finger slides across them is less clear.
What shapes the contact
The authors say the contact mechanics of a finger pad is governed by the fingerprint ridges and by the sweat released from pores located on those ridges.
Friction changes over time
The review reports a result it calls counterintuitive. When a finger touches an impermeably smooth surface such as glass, the coefficient of friction can increase by an order of magnitude, roughly tenfold, in tens of seconds. On a porous surface such as paper, the value goes down instead. The increase is attributed to an occlusion mechanism, in which the contact traps moisture from the skin, and can be described by first-order kinetics.
Friction and touch
For telling textures apart, the review says vibration is clearly important, and friction affects the vibrations made as the skin moves against an object. Friction also has a major influence on how pleasant a surface feels. It adds that a finger pad can show stick-slip, a jerky sliding motion, if friction falls as sliding speed rises, and that the first slip begins at the edge of the contact zone and spreads inward.
What the review does not claim
The review describes how fingerprint ridges and sweat shape the contact. It does not give a single settled answer for why fingerprints evolved.
Sources
- Finger pad friction and its role in grip and touch, Adams and others, Journal of the Royal Society Interface, March 6, 2013: https://pmc.ncbi.nlm.nih.gov/articles/PMC3565724/
Facts checked: October 16, 2026.