It’s a misconception that twins have identical fingerprints. While identical twins share many physical characteristics, each person still has their own unique fingerprint.
If you’re curious about how identical twins are similar and how shared fingerprints aren't possible, read on to learn more.
There are two types of twins: fraternal and identical. The differences ultimately lie in their genetic makeup, or DNA.
Fraternal twins develop from two separate eggs and two different sperm.
According to the Minnesota Center for Twin and Family Research, fraternal twins share 50 percent of the DNA as a result.
Since they share no more DNA than siblings that aren't twins, it’s possible to have one boy and one girl in a fraternal set of twins. This isn’t possible in an identical set of twins.
Identical twins, on the other hand, form within the same egg that splits into two, which results in the two individuals having the exact same DNA.
They share many physical similarities as a result of shared DNA, including hair color, eye color, and skin tone. In fact, it's said that one in four identical twins mirror each other.
Environmental factors can still create slight differences in identical twins’ physical appearances, though, which is how other people can essentially tell them apart. Some underlying differences can include weight and height.
Fingerprints aren't included in these genetic similarities. That's because the formation of fingerprints is dependent on both genetic and environmental factors in the womb.
The chances of identical fingerprints in identical twins is slim-to-none. While anecdotal articles online often discuss the possibility of a chance that the science could be wrong, no research has found that identical twins can have the same fingerprints.
According to the Washington State Twin Registry, identical twins may share similar characteristics of their fingerprints, including the loops and ridges. But having such similarities to the naked eye doesn’t mean the fingerprint composition is exactly the same.
In fact, the National Forensic Science Technology Center states that, “no two people have ever been found to have the same fingerprints — including identical twins.”
Also, it’s important to keep in mind that fingerprints also vary between your own fingers — this means you have a unique print on each finger.
Some studies, however, have touched on the misconception that identical twins have the same fingerprints.
A person’s fingerprints are formed in the womb based on a combination of genes and environmental factors. According to the Washington State Twin Registry, fingerprint patterns are set between 13 and 19 weeks of fetal development.
Fingerprints are partially determined by DNA. This explains why a pair of identical twins might appear to have similar fingerprints at first.
Environmental factors from inside the womb also contribute to fetal fingerprint development, ensuring that identical twins’ fingerprints aren’t the same. These factors may include:
- access to nutrition inside the womb
- umbilical cord length
- overall blood flow
- blood pressure
- position inside the womb
- the overall rate of finger growth
As a result, identical twins may have similarities in the ridges, whorls, and loops in their fingerprints. But upon closer examination, you’ll notice differences in some of the smaller details, including spaces between ridges and divisions between branch markings.
Identical twins share a lot of similarities in both their genetic makeup and their physical appearances. But, like those who aren't twins, identical twins all have unique fingerprints.
Due to environmental factors that affect their development inside the womb, it’s impossible for identical twins to have the exact same fingerprints. Anecdotal observations suggest some similarities exist but there's no research to support this.