Around 2% of your DNA comes from Neanderthals. If we were scared off by them, it wouldn't have been for too long before we decided the sex was worth it.
This gets posted a lot, but nobody ever seems to post what the thing was.
The answer is probably "other hominids". Humans (Homo sapiens specifically) co-existed with them for a long time and competed with them over resources.
Edit: and the genetically deformed (with whom it would be beneficial to not breed, at least from an evolutionary standpoint) and corpses or people with disease
To elaborate more, I think that it's because if humans have an aversion to other hominids and corpses, we wouldn't try to waste resources attempting to breed with them.
As the distance between two species widens, viable (ie, not sterile) offspring become rarer and rarer (although not impossible), so there would be a biological incentive not to "waste time" banging something that looks too different from yourself
...or it's just that requiring co-operative society for our survival wired us to pick up on very subtle facial and figurative signals and signs when it comes to human behavior and anything "off" about it sticks out like a sore and creepy thumb.
No, but the aversion reaction to the uncanny valley is pretty strong. It's more likely an adapted trait than not and can be easily explained by dead or sick humans and animals.
I mean, at some point humans and neanderthals coexisted and even interbred. I don't think it's a stretch that there could have been other similar species that we didn't get along with even earlier than that.
I still don't understand what the uncanney valley is exactly. I've read the definition but not I don't experience it that way I guess? I don't know what people are talking about when they say something is uncanny valley.
I've always understood it as the perception that something isn't quite right (usually with a person, but I've seen it used in non-human contexts too) without being able to immediately describe why.
A great example is Grand Moff Tarkin in Rogue One - the actor who played him on the original trilogy died in 1994, so they just deep-faked him into the scenes he was needed. When I saw Rogue One initially, I didn't know that actor was dead, and didn't connect the dots that even if he wasn't dead, he'd look like a zombie this many years after filming the OT... but in Rogue One, he just looked like Tarkin. Mostly. The scenes that featured him gave a kind of uncomfortable "what the hell is wrong with that guy" feeling, but I still didn't connect the dots and couldn't put my finger on why it looked so wrong.
Then later I learned is was a deep-fake, and now it just looks like a deep-fake; the uncanny valley sensation went away once I finally understood why he looked the way he did.
The internet is full of creepy looking 'examples' of uncanny valley, but they're all shit imo, cuz they're all just blatantly creepy shit; well beyond the uncertainty that goes along with uncanny valley.
I'm decently familiar with deepfakes and I totally didn't notice Tarkin being off when I saw Rogue One in theaters. I was like, "Wow, that actor has barely aged a day since the original trilogy. Good for him." I later learned about it being special effects and was like "Damn, they did a good job. Totally fooled me."
Like, I can see it when I look at it now, only after being told. But the first time, on the big screen? Didn't notice at all.
I've seen some really neat deepfakes over the years. One of my favorites replaces Jack Nicholson with Jim Carrey in "The Shining", so the creepiness kinda helps, lol
One of the best real life examples was the movie Mars Needs Moms.
It was made with a technology called motion capture, and it's absolutely bizarre and unnerving to watch. Everything just looks wrong in a way that's very difficult to explain.
Or the uncanny valley is just not a thing. There's a great video breaking it down, but I don't know where to find it rn. Basically, it's just an experimental artifact of flawed methodology.