Is the L&D section representative of natural selection?

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No it doesn't. Natural selection refers to a process by which a trait is carried forward by either more, or less, of a population as a result of the population adapting to their habitat.

What you're describing sounds more like *one* way of attempting to measure natural selection, but even then it's not a foolproof way. Take Asperger's syndrome, for instance. There are, by default, infinitely more Aspies today than there were 40 years ago because Asperger's syndrom wasn't a diagnosis 40 years ago. Can we then conclude, definitively, that Asperger's syndrom is being selected *for* since there were 0 Dx'd cases in, say, 1970?

Obviously not..



It can if the criteria for determining the trait continues to change to include more of the population, which is why the "green eyes" comparison doesn't work.

The criteria for determining whether or not one has green eyes is unchanging -- they're either green, or they're not.

Not so with ASD diagnoses.



That's true.

autism rates have stayed stable. true that rates of AS specifically are more nebulous, because diagnosis is recent and problematic. which further points to the fact that there is no basis to evaluate whether aspie traits are selected against over time. maybe we should revisit this in a few hundred years?

Not exactly.

There is a study of "high functioning autism" conducted by Rumsey et al (1985) which followed 14 young men aged between 18 and 39 all of whom fulfilled the DSM-III criteria for autism, several diagnosed by Kanner himself. Nine were described as "high-functioning" with verbal IQ's well within the normal range, so basically these were people more inclined towards an AS diagnosis in a time prior to the AS diagnosis.

That is one of the earliest were you have people with "normal/above average" IQ range study groups.

These contain individuals with normal/above average IQ ranges or asperger diagnosis

Venter et al (1992) 22 individuals, canada
Von Knorring and Hagglof (1993) 12 indivuduals out of 88 were AS diagnosed, Sweden
Larsen and Mouridsen (1997) 44 individuals
Mawhood et al (2000) 74 individuals, UK
Howlin et al (2004) 57 individuals, UK and also happens to be my diagnostician

now i am mixed up about which study you are referring to. those studies were concerned with autism, not asperger syndrome.

the study by Rumsey is not applicable for this reason as well. also, that study was only to age 39 - which could be useful to compare with NT populations, but not at all useful to determine how many of the men will ever marry.

we can't compare rates of anything across the DSM III to the DSM IV when we are talking about AS because the DSM III has only autism included - not AS, and these conditions are assessed with different criteria. therefore an HFA with average or higher intelligence is not necessarily equivalent to AS. in fact, in order to qualify for a diagnosis of HFA, a person may not fully fit the DSM IV criteria for AS (and vice versa).

the sample sizes of the last list of studies were small. but anyway what did those studies say, overall? did they contain both women and men? i don't know what conclusions those studies held, so i can't really say anything about them.

regardless, see my last post above. the question itself is moot, as we don't have the data to either support or refute the role of asperger syndrome in natural selection as the condition has not been under study for long enough to tell if rates are increasing, declining, or staying stable.

Science does show this at least - women, neurologically speaking, have more social processing faculties than men. Men have one processing center, women have two. I would agree in the sense that, if there are still more men getting diagnosed than women, its because the ones who aren't and perhaps have to struggle with socializing a bit but perhaps never enough to have society really grab onto it - they're driving on a spare tire, its likely a bit more tiring for them than the rest of the world, but never having been another person - especially when its that mild, many may not even see enough signs to know.

I also think the spread of autism happens often in that couples with traits get together just fine, but with 'traits' its a situation to where it adds flavor or quirkiness to their personalities (makes them interesting) but not enough to make them tank-slap and wreck their bike. Its a bit like sickle-cell anemia, in that having part of the genetics is supposedly advantageous in certain ways, having all of it - well, you have sickle cell.

Ok, so I've been thinking about the whole "are they genetic?" aspect to ASDs.. I sorta wondered about whether or not one could even apply the concept of natural selection to something that may not be genetic at all.

I think we can..

Even if a given condition's not the result of a genetic predisposition, that condition can still affect breeding rates of those who have it.. For instance, if you were born without sex organs -- but your genes were fine -- you'd still pretty obviously be selected *against* because you couldn't breed. Along those same lines, if someone is on spectrum and it affects their ability to procreate (i.e., as a result of rejecting, or being rejected by the opposite sex) then their breeding rate will be affected, which is still a selective process.

To me, it's almost like nature's way of not really caring whether something's genetic or not and simply selecting for or against it anyway, just in case it's a trait that *might* be passed along.

Yep. It is a case of natural selection. Aspie men by in large cannot compete with neurotypical men, and that is classical Darwinsim.

but... we have no evidence that it is selected against. as far as we know, the rates of asperger syndrome are continuing unchecked.

you can't look at one individual's chances of procreating as being a result of natural selection - natural selection is not intended as a predictor of future success, it is an analysis of trends within a population (or genes) over time. and the trends point to no change in the rates of asperger syndrome (or not enough data to tell).

That was meant specifically in relation to men getting dates in the first place by asking women out. I did not say anything about other issues related to dating and relationships, nor does it imply that men have it the hardest on the whole.



That's not what I did though. I was merely trying to demonstrate that those survey results at least qualitatively show that higher proportion of aspie males appear to end up single as opposed to NT males. It was not supposed to be an accurate calculation or a detailed comparison.

Otherwise, do you have a better explanation as to why the single unmarried men in that survey seem to have a higher incidence AS than the general population?



It is not a scientific theory per se, but rather a prediction made from the DSM criteria. That can either be confirmed or falsified by further research.



It did not say it was the only and I don't remember seeing anyone else saying it was either. If that was the only social situation someone had trouble in, then they would not have AS. Social problems in a romantic setting is not a determining factor of ASD, but that does not mean that ASD's can't have an effect on social situations in a romantic setting.

In practice, Asperger syndrome is not significantly different from HFA, in fact one of the biggest differences is the lack of language delay in early childhood. That's why some people in the DSM-V group want to do away with Asperger syndrome as a separate diagnosis and fold it under a single diagnosis of autism. The same issues that would cause problems for an HFA individual trying to find a mate, would also effect an AS individual. Though maybe to a lesser extent in some cases because the criteria for AS is little bit less stringent the criteria for autism.

HFA doesn't exist in the DSM-IV. so the comparison is really between autism and asperger syndrome, and they have some overlap, but the criteria differs:

autism only:
-qualitative impairments in communication (must have this to be diagnosed autistic in DSM IV)

asperger's only:
-no clinically significant general delay in language (must have this)

-no clinically significant delay in cognitive development or in the development of age-appropriate self help skills, adaptive behavior (other than in social interaction) and curiosity about the environment in childhood (must have this)


these are big differences. in order to be diagnosed as autistic under the DSM IV requires at least one criterion that is in direct opposition to asperger syndrome. the DSM V may combine the two, but the criteria will have to change. and the studies cited earlier used the old criiteria, not the potential DSM IV criteria.

OK, here are some links to the articles cited earlier:

Larsen and Mouridsen (1997)

Mawhood et al (2000)

Howlin et al (2004)

Unfortunately, I couldn't find the papers by Venter et al (1992) and Von Knorring and Hagglof (1993). Not all of those studies used the DSM-III criteria and some of them actually did include subjects diagnosed with Asperger syndrome, not autism. The Larsen and Mouridsen study compares the adult outcomes of 9 subjects diagnosed with autism to 9 that were diagnosed Asperger syndrome according to the ICD-10 criteria, including areas of marriage and reproduction. Though, according the abstract, this study seems to indicate that the Asperger group did better than the autism group overall, which I guess is to be expected. I think the Swedish study by Von Knorring and Hagglof must have used the ICD criteria as well because Laz said it included 12 subjects diagnosed with Asperger syndrome but it was published before the inclusion of AS in the DSM-IV. I'm not sure how applicable the Mawhood et al and Howlin et al studies are though.

Jono, thank you for the links. i will have a look at them when i am at home later. i am posting from my phone so i can't go to the articles. if we do accept as a premise, for the sake of argument, that fewer people with AS get married than the general population, it still does not fix the problem that AS does not seem to be decreasing overall, and therefore it cannot be negatively affected by natural selection.