Identical fingerprints

I woke up this morning pondering about whether the fingerprints of identical twins would be identical. Against a background of ongoing debates, in all sorts of areas of psychology and physiology, between nature and nurture. Debates which are often noisy.

So I put the key ‘mother fingerprint twin’ to Bing, who turned up various chunks of popular science on the topic. Also the paper at reference 1.

The answer seems to be that modern fingerprint identification technology can reliably distinguish identical twins. That said, the fingerprints of identical twins are more alike than those of non-identical twins are more alike than those of pairs selected from the population at large.

Furthermore, while the prints of any one finger from a pair of identical twins are generally of the same type – arch, tented arch, left loop, right loop, whorl, and twin loop – this is not always the case. Bearing mind that not everybody uses the same types for these gross classification purposes.

Contrariwise, reference 4 claimed that the fingerprints of identical twins (255 pairs) varied in much the same way as those of non-identical twins (42). But I should want to spend more time with reference 4 before pronouncing on this point myself.

So the fingerprint of any one individual is a product of both nature and nurture. Where nature, that is to say the genes, don’t bother with the fine detail. From the point of view of natural selection, it is enough that there should be lots of (friction) ridges on the fronts of finger tips, but how exactly they might be organised is not important. 

Where I include in nurture more or less anything that can happen to a developing embryo after fertilisation. Presumably amounting to various kinds of random variation of the details, or of the minutiae as they are known, in the fingerprint trade. White noise?

We learn along the way that fingerprint technology is a mature technology which has evolved along with computer technology, with mature products out there with well-oiled licensing arrangements. The companies that make these products are out there to make money, not out of goodness of their hearts. 

We also learned about the annual twins’ festival held in Twinsburg, Ohio. Of which BH turned out to have prior knowledge, from some programme on television. See reference 6.

All seems a long way from the ear description and matching technology which Simenon mentions from time to time, presumably current in the 1930’s.

But maybe tomorrow I will ask Bing about changes in fingerprints during life. The fingerprint of a five year old compared with the same fingerprint fifty years later?

References

Reference 1: Fingerprint Recognition with Identical Twin Fingerprints - Xunqiang Tao, Xinjian Chen, Xin Yang, Jie Tian – 2012. 

Reference 2: https://neurotechnology.com/product-advisor.html. 

Reference 3: VeriFinger SDK: Fingerprint identification for stand-alone or web solution - Neurotechnology – 2020. 

Reference 4: Discriminability of fingerprints of twins - Srihari SN, Srinivasan H, Fang G – 2008. A reference in reference 1 above. 

Reference 5: https://www.theiai.org/. The International Association for Identification.

Reference 6: https://twinsdays.org/. The twins days festival in Twinsburg, Ohio is the largest annual gathering of twins and multiples in the world.

Reference 7: https://en.wikipedia.org/wiki/Twinsburg,_Ohio.  The source of the image above.

Reference 8: https://en.wikipedia.org/wiki/Connecticut_Land_Company. A pointer from reference 7. Another bit of unknown-to-me history of the US. From where we learn that Cleveland is named for one  Moses Cleaveland, 1754-1806.

Reference 9: https://en.wikipedia.org/wiki/Fingerprint. More than most of us need to know about the subject.