One mantra for racists in Britain used to be:
"They all look the same to me."
In 1986, I was in a group of people who went to North Korea. The local guide kept getting me muddled-up with another member of the group. We were all white Westerners and he had difficulty telling our faces apart. We all looked the same to him. It was particularly odd in this case because I had a beard and the guy he kept muddling me with had no beard. But he genuinely had trouble telling our faces apart.
"Everything you experience is an illusion. There is a real world out there but everything you experience about that world is constructed by your brain.
"Babies up to the age of about one year can easily tell the difference between human faces, but they can also tell the difference between primates. Adults find these sorts of faces very difficult to tell the difference between because, as we experience faces, we get more clued-into them. and we store in our brains a representation - a model - of what a face looks like."
To demonstrate this, Bruce Hood showed pictures of two similar-looking human faces and two monkeys' faces. It was easy to tell the two men apart instantly. But we had to search visually to see that the monkeys' faces were different.
According to Bruce Hood, after about ten months, babies retain the capacity to differentiate between human faces they see but lose the capacity to differentiate between primates' faces.
Presumably this is because they see lots of different human faces but very few monkeys' faces and the brain realises it will have to store more nuances of human faces because there will be more interaction with them.
The reason I mentioned being in North Korea is because that country is very isolated. North Koreans see very few Western European faces in the flesh. So, from my very unscientific experience in 1986, I suspect a lot of, if not all, North Koreans think "all Western Europeans look the same ".
I presume that, the more multi-ethnic a country becomes, the less the sentence "They all look the same to me" is heard.
But what I find interesting is that, when I see primary school aged children in the street, they are starting to all look the same to me.
I think I am getting old.
Or people are slowly being replaced by clones.
Both options are equally worrying.