PRINTS
Drawn before birth
Ridges spread across each fingertip in waves from three starting points. How those waves meet decides whether you get arches, loops or whorls.
See the numbers
WHAT THE RESEARCH SAYS
Ten fingertips,
a lot of science.
Your fingerprints were set before you were born.
And the wrinkles after a long bath are not just soggy skin: they are controlled by your nerves. Here is what studies say about both, including where scientists still disagree.
PRUNE UP it is your nerves
Test a claim- Prints form in the womb
- Wrinkles need nerves
- Grip is still debated
- The small print on your fingertips
THE SHORT ANSWER
Fingertips are
built to be different.
Three things research tells us about fingertips.
One of them is still being argued over.
WRINKLES
Your nerves do the pruning
Bath wrinkles come from blood vessels tightening under the skin, an automatic nervous-system reaction, not from skin swelling with water.
Test a claim
GRIP
Rain treads, or not?
A 2013 UK study found wrinkled fingers moved wet objects faster. A 2014 Berlin study of 40 volunteers found no advantage.
Read the debate
FOUR THINGS TO TRY
Look closely at
your own hands.
You do not need a lab to see fingertip science in action. These small experiments use things you already have at home.
Find your pattern
Look at each fingertip in good light and decide whether it is an arch, a loop or a whorl. They may differ finger to finger.
Compare with family
Prints are shaped by genes and the womb, so relatives may share pattern types while every fine detail is different.
Time the wrinkles
In both grip studies, hands were soaked in warm water for about half an hour before testing.
Run your own grip test
Move marbles from a bowl of water with wrinkled and then dry, smooth fingers, and see whether you notice a difference.
TWO NUMBERS WORTH KNOWING
Set early,
tested hard.
One figure on when fingerprints are made,
one from the study that tested wet grip again.
13–19 weeks
Weeks of development when patterns are set
Fingerprints are not purely genetic. Genes interact with the womb environment, including position in the womb, umbilical cord length and the rate of finger growth.
FINGERPRINTS · WSU TWIN REGISTRY
40 people
Volunteers in the 2014 replication
After soaking both hands at 40 °C for half an hour, they moved 52 wet or dry objects through a 5 cm hole. Wrinkled fingers gave no advantage in grip or dexterity.
WET GRIP · MAX DELBRÜCK CENTER
A 2023 study in the journal Cell, with researchers from the University of Edinburgh, found three signalling molecules, WNT, EDAR and BMP, help lay down the ridges.
A QUICK CLAIM CHECK
True, false
or still open?
Pick a common claim about fingers to see what the research says. The bar shows how well the evidence supports the claim.
Based on the studies and reference pages listed in the sources below. General science information only.
THE GRIP DEBATE
Rain treads,
or a mystery?
In 2013, Newcastle University researchers reported in Biology Letters that people moved submerged objects, including marbles, more quickly with wrinkled fingers, while wrinkles made no difference to dry objects. They compared it to tyre treads on a wet road.
A year later, a team at the Max Delbrück Center in Berlin repeated a similar test with 40 volunteers in PLOS ONE and found no benefit for grip, dexterity or touch sensitivity. Why fingers wrinkle is still an open question.
Questions
Questions people ask
Why do fingers wrinkle in the bath?
The wrinkling is an automatic reaction of the nervous system that makes blood vessels below the skin constrict. It is not simply water swelling the outer layer of skin.
Do wrinkly fingers grip better?
The evidence is mixed. A 2013 Newcastle University study found wrinkled fingers handled wet objects faster, but a 2014 study of 40 volunteers in Berlin found no advantage.
When do fingerprints form?
According to the Washington State Twin Registry, fingerprint patterns are set between weeks 13 and 19 of development in the womb.
Do identical twins have the same fingerprints?
No. Identical twins' prints are very similar in their loops, whorls and ridges, but fine details such as where ridges end or branch are different.
How do fingerprint ridges form?
A 2023 study in Cell found the ridges spread in waves from three points on each fingertip: the centre of the pad, under the nail and the nearest joint crease. How the waves meet sets the pattern.
Sources
- Washington State Twin Registry: Do identical twins have identical fingerprints?
- Science News: How fingerprints form was a mystery, until now (2023)
- Kareklas, Nettle and Smulders (2013), Water-induced finger wrinkles improve handling of wet objects, Newcastle University ePrints
- Scientific American: Why do our fingers and toes wrinkle during a bath?
- Max Delbrück Center: Better grip with wrinkly fingers? Researchers find no proof (2014)
Updated