When we meet someone and say they have a beard. When we meet another person with a beard. How do we know that is not the same person?
On the other hand, when we see the same person from a slightly different angle we recognise them.
So how do we not over-fit or under-fit on facial recognition?
Is it just practice?
If we just lived on an island with people who looked very different from each other (e.g. the old one, the tall one, the fat one, the bald one, the young one) and then travelled to a country with lots of similar looking people. Would we think they all looked the same?