Tag Archives: Intellectual disability

Why it matters whether autism is a trait or a unified condition

I’ve written a lot about autism as a trait, contrasting this with a “single unified disorder” narrative.

To me, this is not a nitpick. It matters very much whether we think about autism as a “single disorder” kind of thing, or a “dimensional trait” kind of thing.

Take a popular media article from time.com that came up on Twitter today, about the “Intense World” theory of autism. It’s called “What if people with autism are actually hyperfunctional?” and a sample quote is:

Now, a new study published in the journal Frontiers in Neuroscience suggests that the brains of people with autism are actually hyperfunctional rather than stunted or impaired, and that if treated early in a very predictable environment, symptoms could diminish.

The article goes on to suggest that if autism has this etiology, it should significantly change treatment strategies.

This study is interesting, but it applies to only some autistic people. I don’t think it’s relevant to me or my son, for example.

Results that apply to only some people are still interesting! It isn’t necessary to overhype into a unified theory of autism. But there’s a practical consequence if we only apply a result to a subset of autistics, and that’s the need to figure out which people it applies to.  The autism diagnostic criteria don’t do that work for us.

If we apply a research discovery to the wrong people, then we might harm them by using the wrong approach to helping them.

This particular result, because it’s about being “hyperfunctional,” also continues the disability superpower trope, something that can be harmful by creating feelings such as these. When presenting this kind of “autism as a strength” idea, we have to be sensitive from a human perspective, thinking about autistics who may read about it and think “well, I don’t feel hyperfunctional” or “I don’t seem to have any special skills.” Here’s where always qualifying with the word “some,” some autistic people, can be a small but helpful gesture.

But most importantly — however an article like this one on time.com plays out in practice — it’s inaccurate in a way that deserves correction.

To see this, rewrite it with something we all agree is a dimensional trait, such as intellectual disability, and a single condition that causes that trait, such as Down Syndrome. We might write “What if people with intellectual disability actually have trisomy 21?” and we might talk about how we need to focus on low muscle tone, short stature, and congenital heart disease as central to the treatment of intellectually disabled people.

I think we can all agree that this would be more than oversimplified; it would be incorrect and lead us to flawed treatments. In cases of intellectual disability that are not trisomy 21, we would be badly mistaken to go looking for the characteristics that make up Down Syndrome.

If time.com made this mistake about intellectual disability, they would have to issue a correction. The reason they can mess this up with autism is that autism researchers are also still messing it up, and the mass media follows them. The most cutting-edge researchers are now talking about “the autisms” and so on, but lots of them haven’t caught up.

So whenever some poorly-designed study correlates stuff with autism, and the media reports this as a possible new unified theory of autism, it’s misinformation. Plain and simple. It’s no different from asserting that trisomy 21 is the unified theory of intellectual disability.

There are more known etiologies for intellectual disability than for autism, no doubt. But autism does have some known ones, and there’s no evidence that the remaining idiopathic cases of autism (or intellectual disability) will turn out to be from some unified cause. Most evidence seems to point the other way toward diverse causes.

Discovering trisomy 21 was still a big deal, still very interesting, even though it doesn’t explain all intellectual disability.

When we say “autism is due to intense world,” that’s a much stronger claim than “some autism is due to intense world,” because it requires us to not only prove intense world but also to disprove every one of the other zillion proposed theories of autism. When it comes down to it, quite a few of those theories could be true … for particular autistic people and not for others. To help each person, we need to understand what autism means for them, individually.

Good science and good medicine require us to be precise about our claims and our terminology.


Let’s make autism research more useful

Every day there’s a “something correlates with autism” story; Emily Willingham just did a roundup of weird ones. When I first started to learn about autism, it took no time to realize that these aren’t very helpful. I wish researchers would focus elsewhere, and some already are.

Here are two studies (these happened to pop up today) that did better:

I didn’t dig in on these studies in detail, the point is that their reported findings are much more informative than they would be if they were simply “autism correlated with motor skill impairments” or “autism correlated with de novo mutations.” They go a level deeper and attempt to look at dimensions within autism.

Here’s what’s wrong with a “correlate autism with X” study.

Plenty of evidence seems to support the idea that autism is more like a trait or symptom than a disease. Some people seem to experience autism primarily as sensory differences; others as a different kind of thinking (perhaps in pictures, or in explicit, intellectualized fashion); others emphasize medical issues such as seizures or tuberous sclerosis with autism as an effect. Sometimes autism comes with intellectual disability, other times it doesn’t. It may or may not imply motor deficits. On and on — there are so many differences. We’ve put all kinds of people and experiences together and said: these people have a brain focused on something besides social interaction, and that’s what’s most important about them.

We need to view this grouping as contingent and pragmatic, to be used when it makes sense. If we’re asking, “should we be concerned about this person’s ability to make friends and navigate social situations in daily life?” then the broad “autism” label is appropriate, because it’s defined by something close to that question.

But if we’re asking, “what specific education or accommodation does this person need?” or “what strengths might this person have to build on?” or “do we expect problems other than the core social deficits?” or “what causes autism?” … any practical question, really … we need more specific ways to group and understand people. Just “autism” tells us little, and may even be actively misleading.

“Autism” has a crude yes-or-no quality. If someone is just outside the autism range on the usual autism assessments, are their social skills perfect or might they benefit from extra help in those areas?

What could researchers do to improve?

  1. Measure autism dimensionally … continuing those measures outside the official spectrum. See if the variable you’re looking at also relates to more-autism-like but not-quite-diagnosable “neurotypicals,” for example.
  2. Measure separate aspects of autism separately. Some research suggests that sensory issues and social issues may not be strongly related, for example.
  3. Look for relationships among those variables which aren’t part of the autism diagnosis, but crop up often in autistic persons. Motor skills differences; language differences; picture-thinkers and word-fact thinkers; attention-seeking behavior; verbal vs. non-verbal; presence of medical issues such as seizures.
  4. Some studies have tried to find commonality in “responders” and “non-responders” to intervention; those are great studies! Which people benefit from which kinds of help?

“Autism correlates with X” research really falls over when it comes to debates about the DSM criteria. How are we supposed to improve the criteria by finding things that correlate with the current criteria? Circular and nonsensical.

In the end, a yes-or-no on autism isn’t enough.  We need to describe a person more specifically, including their strengths, and then list social deficits or repetitive behaviors as one aspect of whatever’s going on with that person. Once we understand autism, it probably goes away as a diagnosis and returns as a trait (one associated with certain diseases, perhaps, but perhaps also arising from certain strengths).

There’s plenty of anecdata out there about kinds of people with autism; picture-thinkers, “little professors,” memorization-loving hyperlexics, lovers of sensory experience. It’s time to try understanding these differences in earnest.

Take the study I linked to earlier, reporting that de novo mutations only correlate with autism with intellectual disability? If that turns out to be true, does it mean that some autisms with and without intellectual disability have distinct causes? It’s a fascinating clue.