ms of regional volume differences, the brains of females with autism have a shift toward looking like typically developing males rather than typically developing females. Interestingly, males with autism also show a shift, but in another direction (though with less strong evidence): They shift toward typically developing females rather than typically developing males.
These findings link autism to the so-called ‘typical sexual dimorphism’ (that is, average characteristic differences between neurotypical males and females) at the level of neuroanatomy. Admittedly, similarities in how brains look do not necessarily indicate shared underlying mechanisms in action.
But if such a correspondence is partly valid, our findings may imply that mechanisms contributing to the emergence of autism are somehow related to how typically developing males and females differ, including factors related to sexual differentiation (such as sex chromosome genes and prenatal sex hormones) as well as social-environmental effects related to gendered experiences (such as rearing experiences related to gender stereotypes).
As in most empirical studies, what we found may be limited to the characteristics of the participants involved in the study — here they are all adults without intellectual disability and major comorbidities of autism such as epilepsy.
Piece by piece, subgroup by subgroup, hopefully one day the jigsaw of understanding the whole autism spectrum can be completed. During this process, we should constantly remind ourselves that all subgroups within the broad and diverse spectrum must be equally attended to and understood. As such, autism may be male-biased in prevalence, but our understanding and appreciation of it should not be.
Meng-Chuan Lai is a research associate at the Autism Research Centre of the University of Cambridge in the U.K., and adjunct assistant professor in psychiatry at National Taiwan University.
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