There is more to bigotry than the uncanny valley. Bigotry can be learned also. To some extent the position on an attraction/familiarity curve is only about learning. Brothers and sisters are unlikely to form romantic relationships due to familiarity. Adopted siblings from different biological parents usually don’t become romantically involved either and they are not genetically related. There are cases where brother and sister, separated at birth who later meet are romantically attracted to each other.

There is probably a gender difference. Many white slave owners did rape and father children with their female black slaves. There may be multiple different attraction/familiarity curves for different people and about different things. That hundreds of women have volunteered may be suggestive that for opposite gender reproductive partners, the valley is very close (siblings) and essentially everyone beyond a certain distance is exotic and attractive.

The one thought I have, that run somewhat contrast your thoughts, are that some of the strongest animosity occurs between groups that are geographically close and are often similar in many ways. To an outsider the group conflicts seem to be based up very superficial differences, yet within each group those differences have increased importance. I do agree with much of what you wrote, and there is a decent amount of complexity to the topic

I read about this several years ago and I don’t remember the details well enough to look it up, so my apologies in advance for the vagueness.

I read a letter or something written by a European who came to the United States in the 18th century, having heard about black slavery and been morally opposed to it, but when they arrived, they saw an African person for the first time and freaked out so much that they converted on the spot to the belief that Africans were subhuman. I am not sure if this can be entirely attributed to the uncanny valley; people who see other humans in a state of degradation sometimes respond by agreeing that they deserve to be degraded, so perhaps the European might have had a different reaction if they had encountered an African dressed in expensive clothes and behaving like an important personage. But I think it is entirely possible that we could respond to Neanderthals with similar shock and revulsion.

And, Steve, I think you are much too sanguine about the effect of the Neanderthal growing up as an object of public and scientific scrutiny and knowing that he or she was the only one of its kind. If they are anything like us, that is likely to be extremely traumatizing. The analogy to test tube babies is not apt; test tube babies look just like the rest of us so it is easy enough to keep their identity private. A Neanderthal (probably) couldn’t hide. Given the reasons people have given above for why a cloned Neanderthal might not be representative of “true” Neanderthals at all, and the trauma to the individual, I think cloning one would be extremely irresponsible.

It might have evolved for sickness detection, but other organisms have conspecific recognition which triggers fighting, usually over territory. In social organisms like ants, that detection is based on pheromones and is learned, that is ants that are fostered to a different nest and grow up in that nest act as members and are accepted as members of that nest, even when they are of a different species.

Regarding sickness detection, how could an organism learn the pattern recognition necessary to diagnose sickness without exposure to the proper patterns? Recognizing differences or unique behaviors would be much easier.

I suspect that there is regulation of the “gain” on how different someone needs to be before xenophobia is triggered via the uncanny valley. If you are in a low stress state, then someone different may be perceived to be exotic and not a threat. If you are in a high stress state (and it is stress of particular kinds), then the unfamiliar becomes a threat.

Many social interactions are mediated through oxytocin and maternal bonding is the archetypal social behavior for mammals. All mammals exhibit maternal bonding, even non-social mammals. Maternal bonding has to be regulated, and if times are too hard, too hard for lactation to be successful until weaning, many mammalian mothers will become infanticidal.

I’m not sure that anyone is saying otherwise. My main point was that modern societies have increased exposure to a wider range of human groups (therefore increased phenotypic variations), which likely lessens this “uncanny valley” reaction that people may have if all they knew about were the people in their town or village. This will probably lessen this reaction in a Neaderthal, which was a reaction to d2u’s comment above.

“CC, I think that humans can and do trigger the uncanny valley in other humans and this is the mechanism behind what causes xenophobia”

I think it may be “a” mechanism, but not “the” mechanism. There is far more to “in group” and “out group” than this effect. I agree that there is a huge “learned” aspect to this, using the broadest sense of the term.

Of course, that wasn’t cloning.

The negative emotional reaction to near-human looking beings probably relates to an evolved aversion to people who are unhealthy – either because they may have communicable diseases or because they would be unfit mates.

Xenophobia is more complex, as there is an overlapping attraction to the “exotic.” It is suspected that attraction to the exotic encourages occasional mixing of different genetic stock. It is also not clear if the “in-group” vs “out-group” phenomenon is the same as those emotions triggering an uncanny valley. They may be similar but distinct.

But sure – the uncanny valley can be triggered by humans. Why else would it exist.

http://podcastdownload.npr.org/anon.npr-podcasts/podcast/330/510053/170089058/WBUR_170089058.mp3?_kip_ipx=1682153067-1358974250

as for female volunteers who want to be a surrogate mother to a Neanderthal baby, he says “…hundreds and hundreds have shown enthusiasm…”.

http://daedalus2u.blogspot.com/2010/03/physiology-behind-xenophobia.html

There are different degrees of this, and it is always active more-or-less.

I think this xenophobia represents the apocryphal “greenbeard” mechanism, but it can’t be genetic per se, it has to be learned. Human sensory neuroanatomy isn’t established genetically, it develops through exposure to sensory information, so a specific human pattern recognition can’t be coded for genetically either, it has to occur during or after development of the sensory neuroanatomy that does the pattern recognition.