"Long-held assumptions"?
Language Log 2025-10-04
"New Autism Data Challenge Long-Held Assumptions", MedPage Today 10/3/2025:
Autism diagnosed during early childhood had a distinct genetic and developmental profile compared with autism diagnosed later, a large analysis of multiple cohorts showed.
[…]
The results challenge a long-held assumption that autism has a unified underlying cause.
The cited research paper is Xinhe Zhang et al., "Polygenic and developmental profiles of autism differ by age at diagnosis", Nature 10/1/2025. The abstract ends
These findings indicate that earlier- and later-diagnosed autism have different developmental trajectories and genetic profiles. Our findings have important implications for how we conceptualize autism and provide a model to explain some of the diversity found in autism.
The paper's evidence and its conclusions seem solid. But the MedPage article's reference to "a long-held assumption that autism has a unified underlying cause" is misleading, starting with the implication that "autism" is a category with well-defined, stable, and generally-accepted boundaries.
Several years ago, I quoted from a paper by Laurent Mottron, "A radical change in our autism research strategy is needed: Back to prototypes", Autism Research 6/2/2021, whose abstract starts this way:
The evolution of autism diagnosis, from its discovery to its current delineation using standardized instruments, has been paralleled by a steady increase in its prevalence and heterogeneity. In clinical settings, the diagnosis of autism is now too vague to specify the type of support required by the concerned individuals. In research, the inclusion of individuals categorically defined by over-inclusive, polythetic criteria in autism cohorts results in a population whose heterogeneity runs contrary to the advancement of scientific progress. Investigating individuals sharing only a trivial resemblance produces a large-scale type-2 error (not finding differences between autistic and dominant population) rather than detecting mechanistic differences to explain their phenotypic divergences.
And it's easy to find similar concerns expressed across previous decades.
A few relevant past posts:
"Translating 'phenotypically diverse'", 5/12/2020 "'Reliability is confused with truth'", 6/26/2021 "Intonation in 'human emulation mode'", 5/9/2021 "Grouping-think", 6/9/2022 "RFK Jr on Autism", 4/18/2025
A relevant recent skeet:
The mystery of medical diagnosis!
— Richard Kadrey (@richardkadrey.bsky.social) October 3, 2025 at 2:25 PM
Of course,"stars" are actually a natural kind, though some of the things we see in telescopes turn out to be galaxies and so on.