Humans have 23 pairs of chromosomes, our genetic material also referred to as DNA. The difference between a single chromosome determines your sex, XX women and XY men. Whether you inherit an X or Y has a monumental impact on how you think, act, see and experience the world. We accept that neurotypical men and women are very different, yet it seems we previously failed to appreciate any variants in traits of autism between the sexes.
The first reports of autism were recorded in the 1940s. Scientists believed the diagnosis to be predominantly an extreme of the male brain hence, studies were significantly more focused on boys. Therefore, knowledge about common traits and patterns were valid but specifically when considering autistic males. In recent years, the old studies have been revisited with this in mind. Subsequent research estimates male to female ratios, previously cited to be 10:1, now being around 3:1. The National Autistic Society, 2019, suggested that the ratio ranges from 2:1 to 16:1 [National Autistic Society, 2020], supporting the argument that female autism is not fully understood. Science in this area is just starting its journey.
In the last decade, research has progressed immensely for females with ASD. There is more evidence and knowledge about the variations in presentation of autistic females. There are two main theories for the change in direction when considering female autism – biological differences between males and females (including the female protective effect) and diagnosis bias (the way autism is defined and diagnosed).
The female protective effect suggests that girls are more phenotypically resistant to mutations hypothesised to be linked to autism than boys. Therefore, girls need to have more genetic mutations in order to show signs of the condition [Spectrum News, 2019]. This may be due to men only having one X chromosome, hence expressing these changes more readily [Spectrum News, 2014]. To the contrary, as women have two X chromosomes, it is less likely that a female will have mutations on both X chromosomes so one X with mutations will be masked by the second X without. However, it is unclear whether this directly reflects the gender bias in diagnosis.
The second hypothesis suggests that there is variation in autistic traits between sexes. Just like neurotypical males and females are different, autistic male and female individuals also present differently. For example, a noticeable difference between the sexes is seen in social interaction. Not all autistic females are reclusive and introverted. Many are loud and desire friendships and social interaction. This contrasts with the stereotypical autistic model, and also with the majority of autistic males.
The table below highlights further similarities and differences of autism in both sexes [Dadlani, 2017].
Figure 1
Additionally, autistic females are more likely to actively compensate for their symptoms by masking.
Masking or camouflaging is artificially ‘perform’ social behaviour that is deemed to be more ‘neurotypical’ or hiding behaviour that might be viewed as socially unacceptable (Lai, M., Lombardo M. V., et al, 2016). The motivations for masking symptoms of autism includes fitting in and increasing connections with others. Masking itself is comprised of a combination of camouflaging and compensation techniques where the individual is able to control impulses, act ‘neurotypical’, rehearse answers to questions or conversations and mimic others. The short- and long-term consequences of masking includes “exhaustion, challenging stereotypes, and threats to self-perception” [Hull, L., Petrides, K. V., et al, 2017].
All in all females are, compared to males, in serious risk of their ASD to go undiagnosed. Females are also often diagnosed much later in life than their male counterparts, likely due to misrecognition, better camouflaging abilities and insufficient knowledge of girls and women with ASC [Warrier, V and Baron-Cohen, S. , 2017].
Masking is incredibly exhausting. It requires huge effort to fit in within a neurotypical society and camouflage an individual’s true identity. A ‘high functioning’ autistic individual is probably a pro at masking, meaning you experience their autism mildly and not that they have few symptoms. You may never know how hard they have to work to achieve this disguise. This is another reason why high and low functioning terms are not appreciated within the community. They can be misrepresentative as few and many autistic traits respectively or even mild and severe autism. Masking can lead to serious mental health illness, as can the missed diagnosis of women on the spectrum resulting in feelings of being misunderstood but I’ll leave this topic to another blog.
I am hoping you now agree that research in female autism must forge ahead so individuals can receive a diagnosis in a timely manner to help direct appropriate support from a young age.
Thanks for reading,
Nidhi :)
References
Hannah Furfaro, 2019. The female protective effect, explained. Spectrum. Available at: https://www.spectrumnews.org/news/female-protective-effect-explained/ [Accessed November 7, 2020].
Hull, L., Petrides, K. V., Allison, C., Smith, P., Baron‑Cohen, S., Lai, M. & Mandy W. (2017). “Putting on My Best Normal”: Social Camouflaging in Adults with Autism Spectrum Conditions. Retrieved from https://link.springer.com/content/pdf/10.1007%2Fs10803-017-3166-5.pdf. [Accessed July 18, 2020]
National Autistic Society, 2020. autistic women and girls. Autism support - leading UK charity - National Autistic Society. Available at: https://www.autism.org.uk/advice-and-guidance/what-is-autism/autistic-women-and-girls [Accessed November 7, 2020].
Warrier, V and Baron-Cohen, S., 2017. The Genetics of Autism. Autism Research Centre In: eLS. John Wiley & Sons, Ltd: Chichester. DOI: 10.1002/9780470015902.a0021455.pub2 Available at: http://docs.autismresearchcentre.com/papers/2017_Warrier_The-Genetics-of-Autism.pdf [Accessed July 18, 2020].
Wright, J., 2014. Girls protected from autism, study suggests: Spectrum: Autism Research News. Spectrum. Available at: https://www.spectrumnews.org/news/girls-protected-from-autism-study-suggests/ [Accessed August 7, 2020].
Cover image: Sarah Jacobsson Purewal, 2017. Daily wisdom: why sex matters in research. Furthermore. Available at: https://furthermore.equinox.com/articles/2017/07/sexism-scientific-studies [Accessed November 7, 2020]
Figure 1
Dadlani, A., 2017. Autism Spectrum In Girls. Once Upon a School. Available at: http://www.onceuponaschool.org.au/post/autism-spectrum-in-girls [Accessed July 18, 2020].
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