LETTER:Twin prints

From Mr C. J. Coombes

Sir: A question in "technoquest" (Science, 15 August) asks: "Do identical twins have identical fingerprints?" The first part of the answer reads :

If the twins are monozygots (from the same egg), they will have identical fingerprints.

This is incorrect.

Careful scientific research has proved that the arrangement of the papillary ridges on an individual finger or thumb is not repeated on any other finger, whether of the same or other person, irrespective of relationship. While it is true that a certain correlation of patterns often exists in the prints of twins, there the likeness ends. Identification by means of fingerprints does not depend on pattern-type similarity but on the coincident sequence of the papillary ridge characteristics. That is where the uniqueness of each individual person is displayed.

The second part of the answer provides a misleading statement regarding identity:

Environmental factors and changes after birth, however, are likely to change them later.

Yes, pathological creases will occur and scars may sometimes be formed through injury, but they play no part in the method of making an identification. Mr Puri, from India, states in a paper on monovular twins, dated 1968:

It is a medically admitted fact that the ridges on fingers are formed in the fourth (foetal) month and, whatever pattern and ridge details they assume, only grow in the later months and do not undergo any change.

The simple fact is that fingerprints are formed before birth and persist unaltered throughout life, each being unique to not only the individual but to the digit.

Yours faithfully,

Christopher J. Coombes

Director of Identification Services

S03 Branch

New Scotland Yard

London, SW1

17 August