Published on 12, July, 2020
news article today in the Independent newspaper...
“We suspect that the early development of inherited autism was in part an evolutionary response to ultra-harsh climatic conditions at the height of the last Ice Age. Without the development of autism-related abilities in some people, it is conceivable that humans would not have been able to survive in a freezing environment in which finding food required enhanced skills”, she said.
https://www.independent.co.uk/news/science/archaeology/prehistoric-autism-cave-paintings-barry-wright-penny-spikins-university-of-york-a8351751.html
Good to see those on the spectrum getting some positive acknowledgement..
I want to bump this discussion up the list, and hope the following is comprehensible. Couldn't the theory explain much of how we are different? It fits in neatly with the idea of neurodiversity, and recalls:
The article conjures up a particular autistic phenotype, archetype or stereotype: the tracker, the witch, the monk, the boffin. Where would we be without specialists? Probably extinct, or still in isolated tribes. There would certainly be no settlements or modern society without specialisation, or someone to experimentally and doggedly pioneer that specialism.
(Of course there are dangers with too much specialisation and we seem to require more than more specialists to deal with that. As Carl Sagan said: 'We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology. This is a clear prescription for disaster. It’s dangerous and stupid for us to remain ignorant about global warming, say, or ozone depletion, toxic and radioactive wastes, acid rain.' Relevant to specialisation, Aldous Huxley: 'An intellectual is a person who has discovered something more interesting than sex.')
So if autism is adaptive for the tribe, it explains a few things, 'symptoms' which may or may not occur together; attention to detail, to become fascinated with animal behaviour or where plants are found; intense focus or 'monotropism' and a tendency to special interests at the expense of general communication; 'local processing bias' which the paper describes as associated with talented representational artists; concern with symbolic systems; sensory hypersensitivity to the environment, and hyposensitivity to physical needs and sensory processing differences; both wanting things the same, and seeking out something specific.
These characteristics might differ from those of others, who use much of their brain for understanding social dynamics, emoting and communicating to keep the group together, for their own purposes and for the group's. Apparently it's been found that the regions of the brain that in neurotypical people are used for recognising faces, understanding non-verbal communication and social implications are in autistic people used instead for special interests. This could provide a few individuals (not too many), with enhanced abilities in specialised fields. Those people would be more flexible, in a long-term sense, and diverse. It's been said that autism is like a different 'operating system'. In computing terms, I wonder if it is more like being built without certain optional firmware ROMs, so that social abilities are not hard-coded, but can be learned in general-purpose software.Maybe we can imagine identifying with our forebears in a cave scene by firelight: 'Please stop waving that smelly mammoth leg around. Can't you see I'm trying to finish my PhD painting on "101 ways to skin a sabre-toothed tiger"? Get those breasts out of my face. Stop partying!"The problem I have with the idea is that if there's such a long evolutionary history, why do autistic people find social interaction so much harder? Wouldn't it have been better if people had evolved ability to concentrate on a particular subject, without losing the abilities to see social context and bond emotionally through shared signals? That way, we might have less desire to spend time chatting than we do sorting and studying, but could still socialise when needed to achieve a respectable status with our peers. Some related possibilities:
Autism is not, as is often assumed, a recent phenomenon as the genes coding for autism havea long ancestry, dating to before the emergence of the hominin line. Autism is thus part of the shared apegenome [refs] with autistic traits apparent in chimpanzees(Marrus et al., 2011; Faughn et al., 2015) and autism genes also found in other primates including macaques(Yoshida et al., 2016). These genes play a role in the ‘evolvability’ or capacity to adapt of the ape and humangenome ... individuals with exceptional talents in realistic depiction also commonly experience socialtraits associated with autism ... Spikins et al. (2016) have argued for examplethat the incorporation of autism is explained through understanding that autism spectrum conditions arenot asocial, but differently social, with individuals with autism without intellectual impairment potentiallybringing important skills and fulfilling important roles in society in the past, as in the present ... In the case of those for whom local processing bias also brought with it traits of autism, compulsive behaviour patterns or certain social difficulties, emerging roles for their social and technical skills (Spikins et al., 2016) would explain the positive selection for autism genes through a balanceof skills and deficits.
Well, maybe. I suggested here http://community.autism.org.uk/f/miscellaneous-and-chat/11765/is-aspergers-the-next-evolutionary-step-for-humans that intense autistic traits may be maladaptive for the individual, but adaptive for kin or for the group, because of the cultural advantages the specialist brings that are adopted by the group, or because in weaker combinations or forms, the genes variants manifest more as intellectual 'skills' than deficits.
Cassandro said:The problem I have with the idea is that if there's such a long evolutionary history, why do autistic people find social interaction so much harder?
I suspect we can guess the answers to this, but you're not going to like it...
I posit that throughout human history it has been necessary to make certain tough choices, or "see things through" in impossible circumstances. Under these conditions, seeing things logically rather than being constrained by "what other people will be feeling" would have been an important advantage in terms of survival.
The ice age: the tribe is starving. There isn't enough food. You can see that if everyone is fed equally, everyone is going to die. Perhaps only someone with autistic traits is able to see with clarity what must be done, and see it through:
Prioritise the children older than three years, the women of fertile age, and sufficient healthy males to provide for the tribe and impregnate the females when more food is available to sustain a population increase. Cease wasting resources on the sick, the injured and the old. Children younger than three are unlikely to survive because they are not yet strong enough to survive the harsh conditions, and the babies will die anyway because starvation will cause their mothers' milk to dry up. Exile the sick since in a malnourished state disease will spread quickly. Anyone healthy who succumbs to the conditions can perhaps be put to more immediate use - dinner.
The Black Death: Perhaps only someone with autistic traits would be firm enough to shut out those who may be carrying the contagion, thereby preserving a settlement whilst all those around are stricken, as a result of their "humanity".
Perhaps only those who valued principles above "fitting in" would stand up for what they believed to be right, regardless of the consequences. Clearly, many such individuals would have suffered an unpleasant fate when no one else stood with them - but some would probably have ended up heroes, albeit as a result of the luck of history. These individuals would probably have bred (repeatedly) with multiple females, at least until those females figured out that their hero was actually rather odd, and a bit dull after all.
DongFeng5 said:These individuals would probably have bred (repeatedly) with multiple females, at least until those females figured out that their hero was actually rather odd, and a bit dull after all.
But... did they thrive?
An interesting question.
My initial thought was, "your genes don't care whether you're thriving, just that you've bred successfully".
But then it occurred to me that:
1. Autistic individuals are more likely to have been perfectionists in terms of their craft or trade, and consequently able to produce better items than their peers. Their skill may well have been in demand, leading to lucrative business. They could have thrived if their skill was valued in a world where everything was hand-made.
2. Autistic males are more likely to have suddenly walked out of one life (possibly involving children) only to start anew somewhere else. It's possible they thrived, but equally possible that they were simply serial breeders with different women. If the males were more likely to "move on" they are perhaps more likely to have bred with females who were genetically more heterogeneous than the women from the same village. Offspring of parents who exhibit greater genetic diversity are likely to have been more healthy and less susceptible to disease caused by damage to particular genes within a given human population.