How unique are fingerprints?
Day 102 / 365
There was a time when the illiterate people used thumbprints instead of signatures. So much so that the phrase “Anghootha Chaap” was used to refer to someone who’s less educated.
Fast forward to today, where thumbprints are what the tech-savvy people use. Whether you want to unlock your smartphone or buy a new sim with your aadhar id, fingerprint scanners are your friend.
Why fingerprints are useful
The two factors that make fingerprints so useful are their persistence and their uniqueness. A person’s fingerprints don’t change over time. And as far as we know, fingerprints are unique for every person. Even identical twins, which share the same DNA, have different fingerprints.
What proof do we have about the uniqueness of fingerprints?
To be honest, we don’t have any. We assume they are unique as so far we have not seen an example that contradicts the assumption.
The main concern though isn’t the actual uniqueness of the fingerprints. Rather, it’s the accuracy to which we can detect the differences in two fingerprints. The technology we have is great but it’s not correct all the time. And because of the heavy reliance on criminal investigations, false positives would have grim consequences. There have been cases of people being falsely accused of crimes as severe as murder and terrorist bombings, only to be proved not guilty afterward.
In the most notorious mistaken print case of all, Oregon resident Brandon Mayfield was erroneously fingered by several top FBI analysts as the Madrid train bomber. Fortunately for Mayfield, Spanish authorities tied the prints to their correct owner, Ouhnane Daoud. Ultimately, the FBI was compelled to admit that its bias and “circular reasoning” had led it to target an innocent man.
But our dependence on fingerprints is not going away any time soon. Best we can hope for is that the technology improves so as to reduce the number of false positives.
This post is part of my 365 Day Project for 2019. Read about it here
Yesterday’s blog — What’s Analysis Paralysis