Eli5 why do smiles and human faces which are generally associated with positivity and familiarity respectively so creepy?

Question

For eg if you see a super wide smile or a statue which looks almost human you are more likely to be creeped out than not. Also an example is humans in polar express

In: 0

Answer 1

Google “Uncanny Valley.”. Basically, human-like creatures that aren’t quite human evoke a creepy response in people. Something that looks totally unhuman is okay, but something that looks almost human is weird.

Answer 2

the polar express is just creepy to begin with so I get that, lol!

with most animals showing teeth is often viewed as a sign of aggression/play fighting. creepy/ long-held smiles can be unnerving as it’s hard to gauge intention