The Claim: Identical Twins Have Identical Fingerprints (Published 2004) (2024)

THE CLAIM: Identical twins have identical fingerprints.

THE FACTS: Identical twins often share personality traits, interests and habits. They come from the same fertilized egg and share the same genetic blueprint.

To a standard DNA test, they are indistinguishable. But any forensics expert will tell you that there is at least one surefire way to tell them apart: identical twins do not have matching fingerprints.

Like physical appearance and personality, fingerprints are largely shaped by a persons DNA and by a variety of environmental forces.

Genetics helps determine the general patterns on a fingertip, which appear as arches, loops and whorls. An individual finger can have just one of these patterns or a mixture of them.

While a fetus is developing, the ridges along these patterns are influenced by a number of factors, including bone growth, pressures within the womb and contact with amniotic fluid.

These lead to unique ridge characteristics in each person and finger, said Gary W. Jones, a former fingerprint specialist with the Federal Bureau of Investigation.

Often, identical twins will have a similar arrangement of patterns, but never the same minute details.

"It's impossible for people to have identical fingerprints," said Mr. Jones, who now works as a private consultant in Summerfield, Fla. "The study of fingerprints has been around for about 100 years, and in all that time, two people have never been found to have the same prints."

The patterns on a person's fingers, palms and feet are fully formed by roughly the fifth month of pregnancy.

They stay the same throughout life, barring any changes brought on by severe mutilation or a skin disease.

But even then, they change very little.

John Dillinger, the notorious Depression-era gangster, famously tried to alter his facial features and obliterate his fingerprints with acid to elude authorities. After Dillinger died, experts discerned a few of his remaining ridge patterns and identified him easily.

THE BOTTOM LINE: Identical twins never have matching fingerprints.

ANAHAD O'CONNOR

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