What is dermatoglyphics?
Dermatoglyphics is the scientific study of the skin ridge patterns on our fingers, palms, toes and the soles of our feet. The word was coined in 1926 by the American anatomist Harold Cummins. It comes from Greek words meaning "skin" and "carving", which is a nice way to describe the fine ridges you can see if you look closely at your fingertips.
This skin is called friction ridge skin. It is different from the skin on the back of your hand. It has no hair, it has many sweat pores, and it is covered in tiny raised lines.
What the ridges are for
Friction ridges seem to help us in two main ways:
- Grip. The ridges and the sweat from their pores help fingers hold on to objects, a bit like the tread on a tyre.
- Touch. As your fingers move across a surface, the ridges help create tiny vibrations that nerve endings pick up. This helps us feel fine textures.
How the patterns form
Friction ridges form early in pregnancy. In the first few months of development, small swellings called volar pads appear on the fingertips and palms. Ridges then start to form in the deeper layers of the skin, roughly from the end of the third month. The basic patterns are set by around the middle of pregnancy.
The shape of each pattern seems to depend on many things happening at once:
- the size and shape of the volar pads, and when they shrink back
- the timing of ridge formation
- pressure and growth in the surrounding tissue
- genes, which influence general pattern types, though not the fine detail
Because so many small, chance factors are involved, the fine detail of every finger is unique. Even identical twins, who share the same genes, have different fingerprints. Their patterns are often similar in overall type, but the details differ.
After birth, the patterns stay the same for life. Your fingers grow, so the prints get bigger, but the arrangement of ridges does not change unless the deeper skin is damaged by a serious scar.
Loops, whorls and arches
In the late 1800s, the English scientist Francis Galton studied thousands of fingerprints and described the three basic pattern types still used today:
- Loops: ridges enter from one side, curve round and leave from the same side. This is the most common type.
- Whorls: ridges form circles or spirals around a centre.
- Arches: ridges flow from one side to the other, rising in the middle like a wave. This is the least common type.
Experts also look at triradii (points where three ridge directions meet), ridge counts, and tiny features called minutiae, such as places where a ridge ends or splits in two. The palm has its own patterns too, in areas such as the base of the fingers and the outer edge of the palm.
A brief history of fingerprint science
- Fingerprints were pressed into clay as marks or signatures in ancient Babylon and China, long before anyone studied them scientifically.
- In 1823, the Czech physiologist Jan Purkyne described several fingerprint pattern types.
- In the 1870s and 1880s, William Herschel in India and Henry Faulds in Japan both noticed that fingerprints could be used to identify people.
- Galton's work in 1892 showed that prints were unique and lasting, and set up the classification system.
- By the early 1900s, police forces around the world were using fingerprints to identify people.
Dermatoglyphics in medicine
Because ridges form at a particular time in early development, doctors and researchers have studied whether unusual patterns are more common in some genetic conditions. Some patterns do appear more often in certain conditions. But a ridge pattern on its own does not diagnose anything. Many people with "unusual" patterns are perfectly healthy. Today, genetic tests have largely replaced ridge analysis for medical purposes.
If you are worried about your health or a child's development, a doctor is the right person to ask. A fingerprint cannot answer that question.
Where folklore and marketing come in
Some palmistry traditions give meanings to fingerprint patterns. A whorl, for example, is sometimes read as a sign of an independent person, and a loop as a sign of an adaptable one. These are symbolic ideas, not findings.
In recent years, some companies have sold "fingerprint tests" that claim to reveal a child's intelligence, talents, learning style or ideal career. These claims are not supported by scientific evidence. Fingerprints are excellent for telling people apart. They are not a window into the mind.
How to look at your own prints
- Wash and dry your hands, then look at a fingertip under bright light, using a magnifying glass or your phone's camera zoom.
- Find the centre of the pattern. Do the ridges loop back on themselves, circle around a point, or flow straight across?
- Look for small triangles where three ridge directions meet. A loop usually has one, a whorl two, and a plain arch none.
- Check all ten fingers. Most people have a mix of patterns, and the same finger on each hand often has a similar type.
It is a simple, surprisingly absorbing way to see a bit of your own biology up close.
What fingerprints can and cannot tell us
- They can identify a person very reliably, because they are unique and do not change.
- They can give researchers clues about early development, across large groups.
- They cannot reveal personality, intelligence, talent or destiny.
- They cannot diagnose a health condition on their own.
Try it
Take a close look at your own fingertips with a magnifying glass or your phone camera. Can you spot loops, whorls or arches? For a broader look at your hand, try the palm photo scanner, which runs on your device and explains clearly what it can and cannot detect.