I doubt that premise. Neanderthals looked different, but not uncanny valley. Horror and fear may have been involved sometimes, but so was sex and competition... Neanderthals probably just looked like big chinless people
According to commercial genetics testing, I'm more Neanderthal than 90% of other people that used the same major company. My ancestors were into some kinky 👉👌
You would think so, right? But funnily enough, whenever we find a new type of hominid that existed around us (neanderthals, denisovans, homo florensiensis), we find out that humans interbred with them and they are a part of our modern human DNA.
I bet humans learned to "other" things that look like humans so they could do things like avoid the sick and dead, dehuminize other tribes to kill them in war. All the very human things we do now.
It would be a evolutionary benefit to fear / avoid any person that is behaving strangely in certain distinct ways. Could be a dangerous transmittable disease, i.e. rabies etc.
Alternate theory: The human brain is reacting to unfamiliarity and not alien features. We strongly associate Uncanny Valley with things not-quite human but it’s my thinking that it’s a tribal thing. Nowadays we see a ton of faces of all variations but I bet when we were hunter gatherers, we only saw features of our own tribe. The moment you meet another tribe, I’d bet this response is to create fear of the unrecognized human. It’s also probably there as a punishment mechanism for us seeing faces in everything.
The times that the uncanny effect hit hardest is when you think something is human or is a face potentially before finding out you’re wrong. So that’s my basis for thinking its there to keep us from being mistaken.
The humanoids we evolved from were at one point, not the only humanoids around. We coexisted with other, different species (neanderthals being an example). Homosapien is just the one that survived.
I mean, racism has as much reason to exist now as it ever did. "I'll protect me and what's mine" has been the dividing line between species for thousands of years, and we have to choose whether we'll continue it. A "Kill or be killed" mindset might keep you safe, but you'll never know if the person you killed did indeed mean you harm, or if you could've instead lived without killing, and broke bread with a rival. The logic still applies
