Autistic individuals are NOT Neanderthal hybirds

A while ago I wrote about the Neanderthal theory of autism (NAT). For those of you who don’t remember (and are too lazy to click on that link), it’s the idea that autism spectrum disorder is a result of having additional Neanderthal genes.  Everyone is about 4% Neanderthal and NAT proponents believe autistic individuals simply have a higher percentage; and that autism is not a condition but just a result of the fact that there were social differences between us and Neanderthals.

It’s an idea that should not be immediately dismissed for it has a bit of plausibility. However, plausibility only gets you so far and the evidence proponents give to make up the difference is wanting. All they do is try and find any similarity between Neanderthals and autistic individuals before claiming it as proof. For starters, this method is hopelessly unscientific. In science you make a prediction about how something should be if your hypothesis is correct and then check to see if it actually is that way. This (hopefully) avoids mistakes like cherry picking data and other nasty problems.

However, I think the biggest problem with the NAT evidence is that the similarities they claim as evidence are simply false. Descriptions of autistic traits come from informal internet surveys and descriptions of Neanderthal traits come from inside the author’s head. The result is that I wind up breaking into giggling fits whenever I try and read the NAT website.

My favourite piece of evidence is the claim that autistic individuals like walking on their tippy toes, which shows they are Neanderthal hybrids because Neanderthals were good hunters and had to sneak. 

Photo of a Neanderthal hunter in action

Despite this top quality evidence, many continue to advocate NAT. In fact, I’ve received a far few critical comments on my original article. That’s right, people have dared to criticise me! The nerve. These critics all made reference to genetics. The claim is that autism is less prevalent in Africa, where Neanderthal genes are less common. This correlation between Neanderthal genes and autism is one of the best pieces of evidence in favour of NAT.

Of course saying that it’s the best piece of evidence for NAT doesn’t say much when it’s crammed in with gems like “Neanderthals worked wood, therefore they could’ve made fences, therefore they were farmers, which explains why autistic individuals like animals.”

Except on closer examination, this top quality genetics data falls down. For starters the lower rates of autism documented in Africa come from very few studies. Whilst interesting, there simply isn’t enough data to make any claims about the prevalence of autism in Africa. Almost every psychologist with an interest in the field concedes that, as good as these few studies are, they simply aren’t comprehensive enough to identify the autism rate in Africa.

A work around to this problem would be to examine the autism rate amongst Africans living in Western countries where autism diagnosis techniques are more comprehensive and larger amounts of data is available. Unfortunatley for NAT proponents when these studies are performed they do not find a lower incidence of autism amongst Africans. In fact, many even document a higher rate than in the general population!

In short, the only decent piece of evidence in favour of NAT is non-existent. There is not the correlation between genetics and autism rates one would expect if the NAT is true, providing very strong evidence that it is actually untrue. Hopefully this means we can put the NAT behind us once and for all and start looking for the real cause of autism. Like aliens.

Also, I expect comprehensive apologies from all my critics for saving them from nonsense. If you can’t figure out just how to express your gratitude I also take monetary donations.

22 thoughts on “Autistic individuals are NOT Neanderthal hybirds

    • If you look at the differences between European people and African people that might help give you an idea to what the genes from the neanderthals do.
      I think in general they make a person broader with thicker bones. and it is theorised that ginger hair came from them and i think certain eye colours have been theorised to come from them.

    • “And so my version of the androgen receptor…is likely to correlate with hair loss after the age of about 25…This is the part of my genome that I share with Neanderthals.”–John Hawks

      Also:
      “Mutations in several genes in Table 3 have been associated with diseases affecting cognitive capacities. DYRK1A, which lies in the Down syndrome critical region, is thought to underlie some of the cognitive impairment associated with having three copies of chromsome 21 (64). Mutations in NRG3 have been associated with schizophrenia, a condition that has been suggested to affect human-specific cognitive traits (65, 66). Mutations in CADPS2 have been implicated in autism (67), as have mutations in AUTS2 (68). Autism is a developmental disorder of brain function in which social interactions, communication, activity, and interest patterns are affected, as well as cognitive aspects crucial for human sociality and culture (69). It may thus be that multiple genes involved in cognitive development were positively selected during the early history of modern humans.” —Pääbo et al

      I don’t know why my other comment was deleted, but I linked to a video presentation on a variant of the NAT. The title is “Neanderthals and Neurodiversity” (the a 10-minute overview and the 2-hour presentation are both on youtube).

      • The section from Paabo et al., you’re quoting is when they use the Neanderthal genome to work out which bits of the human genome are derived relative to them, i.e. have emerged since we split with Neanderthals. They then look for evidence of positive selection in these regions to see what was being selected for since we split with the Neanderthals.

        As such those mutations you talk about are unique to humans and were not obtained through inheritance or interbreeding with the Neanderthals. Thus they provide no support for the NAT.

        • This is just plain wrong. At least 2 autism genes have been found in Denisovans, which are related to Neandertals. You need to deal with it.

      • The idea that autism arose in archaic hominins does seem to carry a bit of weight in the scientific community; although it’s far from a commonly accepted position. However, in the light of increasing genetic evidence even the strongest proponents of an archaic origin of autism are abandoning Neanderthals as the “source” of autism, instead suggesting it may have been early modern humans.

    • A hybrid is the offspring of two different species mating. Famous examples include the Liger, which is the child of a tiger and a lion. However, they are more common in the plant world. Tabacoo is a hybrid of other plants. Whilst most hybrids are infertile, this is not always the case, as Tabacoo and the Neanderthal/human interbreeding demonstrates

      • You don’t seriously address and deal with the Rhesus negative – what do you think that does ? Were Denisovans rehsus negative ? Or maybe H. erectus ? Or did it come about when Chromosome 2 fused ? You don’t deal very well with the Chrosome 2 issue, either.

  1. Lots of problems with the review. To me it looks like the author didn’t read the theory thoroughly.

    1. The Neanderthal theory haven’t claimed that the source of ASD comes directly from Neanderthal since at least 5-10 years ago. It claims that we got the the traits by introgression with Neanderthal, and that neurodiversity is close to 2 million years old (thus predating Neanderthal by 1.5 million years).

    2. The theory is extremely scientific, since it claimed that we interbred with Neanderthal many years before Pääbo finally proved this to be correct. It also made several other predictions that were tested and confirmed in Aspie Quiz.

    3. While there appears to be some correlation between neurodiversity and the 1-4% DNA introgression believed to come from Neanderthal (0.1, p < 0.05), it doesn't explain ASD, but we already knew that a few mutations cannot explain ASD anyway. The material from the Neanderhal genome project cannot be used to prove/disprove NAT since it only contains point mutations, not copy number variation, which seems most promising for a genetic background.

    There are other things I could bring up, but I await the peer-review of my Aspie Quiz paper.

  2. You realize, of course, that someone writing about the question of Neanderthal admixture with Human DNA 20 years ago would have poo-pooed the idea just as soundly as you are this NAT? While scientists must be critical, especially when there is no evidence in favor of NAT at all, they should also keep an open mind when research has not even been conducted to test a hypothesis in earnest.

  3. Artem Kaznatcheev said: I think the whole point is that it is not a scientific theory, but just pseudo-scientific speculation.
    Agreed. It is a hypothesis that doesn’t have sufficient evidence to make it a theory. My favourite hypothesis is that Autistic people are not a different species than other humans, but a different sub-species. Basically, most humans are Homo sapiens sapiens, but Autistic people are Homo sapiens autistica. I think that works to explain both our differences and the fact that we can arise from previously non-Autistic ancestry. It may also be where Autism $peaks UK got the name Autistica from.

    • i sure hope someone does an analysis of autistic people’s DNA to test the hypothesis. It’d be cool to know that neanderthalish people walked among us even today. Perhaps it would allow others to see them in a new, more respectful light.

      • THere has been some study of this, which failed to find several of the genes associated with autism in Neanderthals. However, it wasn’t really supported with a lot of data (not to say it was wrong, just poorly referenced). However, to my knowledge there’s been no such investigation of autistic people. That would certainly be very interesting and quite plausible these days. For a few hundred dollars 23andme will tell you how Neanderthal you are. See if it’s higher than average.

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