Neanderthal theory has been updated

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Perhaps you can provide your definition of "neurodiversity" for us. My understanding is that the term arose from the Autistic community to present or recognize the view that Autism is a natural condition on the same level as "normal".

Scientific definition of neurodiversity: Neurodiversity is the primary factor output by factor analysis of a dataset of human subjects which contains evenly distributed traits of all sorts that covers all of human diversity.

My knowledge of factor analysis is fairly limited. That definition doesn't make any sense to me considering what little I do know about it, but perhaps you are using it in a way that is not apparent.

Perhaps you can provide an example calculation with an explanation.

Factor analysis is a method to extract variables that are connected. Thus, when all traits in human diversity are checked in a dataset, and the traits are evenly distributed, we would expect no factors to be present in the material at all. It's like if you try to find connections in a material of random values, you shouldn't find any. But since neurodiversity is not random mutations in our genome, but a set of correlated traits, you will get a major factor that explains as much as 60-70% of the variance in the dataset. These correlated traits are the basis for neurodiversity, and their relative contributions are governed by their factor loadings.

So what traits are you considering?

After the calculations, which trait or traits emerge as the major traits (high factor loadings)?

Are you doing a single factor, two factor, or what? Where is this information published?

Sources?

Pretty simples. There is no neanderthal DNA in origin african people, but there are origin african people with autism.

That's obviously wrong. Pääbo calculated that african origin people had 1% Neanderthal DNA while non-African had about 4%. That's because no human populations have been isolated for 30,000 years. Because of the same reason, we don't expect no autistic people in any population.

Wasn't that 1% specifically for North Africans?

Sub-Saharan populations are the only ones not affected by the admixture event with Neandertals.

yes. sub-saharan africans do not have the DNA that is believed to be neanderthal.



http://www.plosone.org/article/info%3Ad ... ne.0047765

autism is believed to occur in similar rates there though.

OK, so then I assume you don't believe that the 10% caucasian minority in South Africa have any European or Neanderthal ancestry, because there is no European DNA in Sub-Sharan populations?

OK, so then I assume you don't believe that the 10% caucasian minority in South Africa have any European or Neanderthal ancestry, because there is no European DNA in Sub-Sharan populations? And of course you know for sure that no white farmers ever existed in countries like Rwanda, and that this is just something invented out of the blue?

i think they were referring to ancestry, not where people moved in recent years. i suppose you could read the actual study, as my beliefs are not really relevant.

OK, but then how could you use one definition (only ancestry) when proving that no Neanderthal DNA exists in Sub-Saharan Africa, then a totally different when you refer to the possible prevalence of ASD? Besides, I'm pretty sure there is no ancestry-based prevalence studies of ASD in Sub-Saharan Africa, and I doubt there are even any total-population studies that used a representative sample, so therefore you assertion that ASD is just as common in Africa as anywhere else is not supported by any scientific research.

The earliest research on autism in Africa was carried out by Victor Lotter as far back as 1978. His research was carried out in 6 African countries. The result of his research was a low prevalence of autism. However, his research methods appeared to be flawed. Since then, not a lot of a studies has been carried out on this disorder. The prevalence rate in the various countries on the continent is unknown. Outside the African continent, it has been observed that children born to Africans immigrants in Europe exhibit a higher prevalence of autism compared to the indigenous population.

This was not a study of prevalence. Yet from indirect evidence the numbers of autistic children found was much smaller than expected. For example, in Middlesex between 5 and 8 per cent of all severely subnormal children would be expected to show some marked autistic behaviour (Lotter, 1966). At least 400 of the 1312 children seen in Africa could be considered severely subnormal, and we were able to identify altogether only nine children as autistic, not all of whom were severely subnormal. If the incidence of childhood autism is assumed to be similar in Africa and Britain, there is no obvious reason why relatively fewer such children should be found amongst the known severely subnormal population in African countries. A possibility therefore is that autistic symptoms generally are less common in the African countries we visited, than in Britain.

A further possibility is that certain specific aspects of the syndrome occur less frequently in the African populations. In our comparison of symptoms there was for example some indication that certain repetitive movements (e.g. flapping, rocking, headbanging) as well as more elaborate ritualistic activities involving objects were uncommon. In institutional populations these kinds of activities may be important in the selection of "possible" autistic children. Stereotypes generally are reported to be very common amongst American institutionalized children (Kauffman and Levitt, 1965a, b). Our general impression, confirmed informally by psychiatrists and other institution personnel in every country we visited, was markedly different from that described by Kauffman and Levitt who state, "a visitor to an institution for mental defectives is quickly impressed with the large number of patients engaged in various forms of stereotyped behaviours" (1965a, p. 467).

...

The relationship between the occurrence of childhood autism and social class, first described by Kanner (1943) cannot readily be accounted for by selective referral (Lotter, 1967). Attempts to establish a relationship between occurrence of the syndrome and parental personality or attitudinal characteristics have not been successful (Rutter et al., 1971). Our findings in Africa invite a different approach to the question, involving the assumption that the relative prominence given to certain symptoms in case definition may determine the social background characteristics of the sample. A case can be made for this view, as well as for the specification of "autism" or "social withdrawal", and repetitive, ritualistic or compulsive behaviours as the symptoms which may be involved.

Total ASD prevalence was higher for NHW (Non-Hispanic White) than NHB (Non-Hispanic Black) children, but NHB children were more likely than NHW children to have autistic disorder and autism eligibility at a public school documented in records. NHB children were less likely than NHW children to have pervasive developmental disorder-not otherwise specified and Asperger's disorder documented in records, even after controlling for socioeconomic status. NHB children were more likely than NHW children to have co-occurring intellectual disability.

It may be important to recall therefore that until about two and half decades ago, autism spectrum disorder was thought to be exclusively an illness peculiar to Western civilization. The existing evidence then suggested that autism occurs mostly in countries with high technological development, high level of industrialization and with salience of nuclear family system. However autism spectrum disorder was also believed to be relatively uncommon even in Western Europe and North America at that time. Nevertheless, the idea that autism may not exist in Africa was further supported by very infrequent report of cases on the continent and other parts of the world outside the West. These observations led Sanua to raise a debate and a pertinent question in 1984 in a paper entitled, “Is infantile autism a universal phenomenon? An open question” (Sanua, 1984).

...

Second, there was a preponderance of boys among children who exhibited such behavior combination and such presentation tended to be more common among African children with moderate to severe intellectual disabilities (Lotter, 1980). Third, there was overrepresentation of children of parents of high socio-economic class among the children described as having features of autism (Lotter, 1980). Fourth, there were certain differences in frequency of specific behaviors between African children and children from Western Europe and North America, notable of which is stereotypic repertoire of behavior which was observed to be less common among African children compared to their counterparts in the West (Lotter, 1980). This is important because the stereotypic repertoire of behavior is an aspect of the main criteria for diagnosing autism spectrum disorders (Lotter, 1980).

...

Co-morbid conditions associated with autism spectrum disorders in Africa: Of the co-morbid conditions diagnosed in association with autism spectrum disorders among African children and documented in the literature coming from Africa, intellectual disabilities are more common.

Belhadj et al (2006) found co-morbid intellectual disability in over 60% of cases in their clinic. Other noted co-morbid conditions in association with autism spectrum disorders among African children included epilepsy (Belhadj et al, 2006) and oculocutaneous albinism (Bakare & Ikegwuonu, 2008). Co-morbidity of epilepsy and intellectual disability in association with autism spectrum disorders found by the study from Tunisia is an interesting finding (Belhadj et al, 2006) as it corroborated the observation of Mankoski et al (2006) from Tanzania, that autism spectrum disorder in Africa is rarely diagnosed exclusively of intellectual disability. This observation is also in tandem with that of Lotter documented about three decades earlier (Lotter, 1980). Therefore, the relationship between autism spectrum disorder and intellectual disability among African children need to be further explored in well designed clinical and epidemiological studies.

From http://globalhealthafrica.org/2012/11/10/170/: