Asperger's difference in IQ subset scores

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I've been seeing claimed at places that Asperger's is associated with a large difference between Performance IQ and Verbal IQ (with verbal IQ being far higher), yet I've not seen anything to support this other than the thought that NVLD is a subset of Asperger's.

Personally I don't have a huge gap between those at all. I was given the WAIS-IV so given scores as four subsections (two of which would fall in each), and VIQ has the strongest and weakest (which are still within a standard deviation). My estimation is that I'd have something like a 5 point difference, not the 15, 30, or 60 point different people talk about in NVLD.

So I was wondering, is this difference actually normal in Asperger's diagnoses, or is it normal in specifically the people with NVLD diagnoses (which does involve similar traits to Asperger's).

I saw a study here on how people with Autistic Disorder perform on various IQ tests as adults and as children, and there performance IQ was actually slightly higher than verbal IQ on average. Children performed worse than the general population on everything on average, but Raven scores were still leagues ahead of there other scores, and as adults they still performed worse than the general population on Performance and Verbal IQ, but there Raven scores were slightly higher than the general population, and after inquiring on whether the studies was just classic Autism or the whole spectrum, I was told that the study was just Autistic Disorder, but the trends carried carried on through the whole spectrum (between the forms of IQ, not between Autistic intelligence and normal intelligence).

Tuttle, in the thread about Asperger's and giftedness, I linked a study in which the researchers concluded that IQ test scoring cannot be reliably used in diagnosing autistic spectrum disorders. There's simply too much variation across the board.

Of course, it is just one study, though they did have a fairly large sample.

Okay, that supports my "but you seem to be talking about NVLD and callimg it AS and this doesn't make sense to me" reaction to those statements.

Does anyone know the percentage of the AS population with a big gap in PIQ vs. VIQ scores?

I don't have the gap. When I was little, my verbal scores were the lowest, but they have caught up since then.

I was looking at this article the other day (full text is online). It's a study of WAIS subtest scores for AS and "autistic disorder."

And there's a table of WAIS subtest scores for AS, AD, and both groups together. I can't get them to work inline so here are the links. The scores are actually not dramatically different from normal.

http://www.ncbi.nlm.nih.gov/pmc/article ... able/Tab5/

http://www.ncbi.nlm.nih.gov/pmc/article ... able/Tab6/

http://www.ncbi.nlm.nih.gov/pmc/article ... able/Tab4/

While they show that the VIQ vs. PIQ difference is not statistically significant, they did find 2 patterns that are.



(My WAIS scores manage to fit both profiles at the same time. Don't know what that means. )

I've haven't done enough looking yet to tell if this article has been reinforced or refuted by subsequent research.

People with Asperger's syndrome typically display a gap between Performance IQ and Verbal IQ. My Verbal IQ, for example, was in the highly gifted range on the WISC-III (140s), and my Performance IQ was only in the average range (high 80s). Neurotypical children and adults have more even results. I only took this test once when I was nine years old. My gap was so significant that my neuropsychologist was shocked I wasn't diagnosed right then and there (in 1997). Instead I was diagnosed in October of this year.

Sources: This video (Autism Europe): http://www.youtube.com/watch?v=nQMCGwFBrx8

Tony Attwood's book: The Complete Guide to Asperger's Syndrome.

Watch the video, it will be most helpful.

I'm still somewhat steaming about the diagnosis I was given recently (that frickin' PDD-NOS). The main reason why they denied giving me an Asperger's diagnosis was that my VIQ is significantly lower (or much lower, IDK) than my PIQ. They also told me that I'm slow (I wasn't surprised, though). I'm determined to look into more details of the assessment in the forthcoming weeks.

It seems rather confusing that a lot a people with AS diagnoses seem to have this very same pattern.

I'd managed to miss the things in my copy of The Complete Guide to Asperger's Syndrome when I was looking on this before. I'm not sure how.

Having looked in The Complete Guide to Asperger's Syndrome now, some studies said this was true of a plurality but not a majority, and other studies contradicted it. As a whole they at the moment say that when young there's often a gap (almost 50% of cases), but as children age the gap lessens.

Also, in this section is listed many studies that said that this can't be used to make a diagnosis.

(I am quite confused at that comment about AS rather than NVLD for you typewriter, though the part of gap reducing with age in people with AS might be relevant to you too)

For the percentage numbers, it gives me that people studying the kids at Asperger's clinic,
48% significantly higher VIQ then PIQ
38% (of those with Asperger's Syndrome) no significant difference
18% (of those with Asperger's Syndrome) significantly higher PIQ than VIQ

(The fact that they were adding up to 104% was really bothering me until I realized the 48% was probably different data set than the other two)

So, OJani, you might be interested in that and have that make you feel less odd.

Oh yes, thanks, and this article too: http://www.high-functioningautism.com/2 ... erent.html (Implying that in a sense giving a PDD-NOS diagnosis to certain types of "HFA" individuals is currently the only way to give them an official DX. Why some clinicians diagnose such individuals with AS is a different matter.)

Right. I am certainly curious to know how I've compensated since age nine, especially without a diagnoses most of my life. My neuropsychologist explained that I was diagnosed with Asperger's and not NVLD because of my rigid routines, extremely narrow interests, and my sensory issues. Not to mention stimming and all of that. Forty-eight percent is still a very significant number.

Watch the video, too, Tuttle. It has some great statistics and explanations.

Ah, so it wasn't about "why weren't you diagnosed with Asperger's then" it was "why weren't you diagnosed with anything then"? That makes far more sense.



Wasn't meaning to question your diagnosis, just was confused by the "why weren't you diagnosed with Asperger's when you got that wide of a gap" because that's not how its diagnosed.



It's still a plurality yes, though if you look at the other two numbers that seem to be from the same data set while this one is from a different one it looks like, the number is more likely 44% and the difference between 44% with a significant difference in that direction as children (and not necessarily as adults) and 38% without one as children, is actually not necessarily that big of a difference.

A minority have PIQ drastically larger than VIQ is far more meaningful of a statement than a 6 percent difference, especially when we don't know error pounds.

Also, and more relevantly since I've looked at the reported statics more, there's a big difference between "A larger percentage of people with AS than NTs have a drastically higher VIQ than PIQ" and "Someone with AS is likely to have a drastically higher VIQ than PIQ".

In the first, you're comparing to populations, and the 48% or 44% or whatever it is is relevant.

In the second you're looking within the population, and from knowing that someone has AS, you can't know that they likely have this trait, and from knowing they have this trait that they likely have AS.

So I think the information you were talking about, and the question I was asking, weren't answering the same question. (And I was being confused by this because they were presented as the same because neither of us realized they weren't)



I'll likely do so later. Not doing anything with sound now.

I don't even know my IQ and I was diagnosed with aspergers.
I don't think there is a record of the IQ score of everyone with AS.
It would be impossible to prove this without giving everyone diagnosed with AS an IQ test and recording the results.

I think a noticeable number of us are given IQ tests with our diagnoses so there might be enough data. I know I was. I think it was testing for NVLD and he wanted it to compare my IQ with what percentages I was scoring at for things like reading faces.

The solution is obviously that we modify the census so instead of focusing on economic standing it's focuses on neurology. Everyone will be given 50 different IQ tests and an intense psychological evaluation, and will be diagnosed with whatever they have. Someone help me sign a petition to Obama, this will makes studies so much easier. [/half-sarcasm]

Being a fan of purer mathematics I never trusted statistics.