Hidden in plain sight: The underdiagnosis of Autistic girls

June 1, 2023

Two girls sitting on the grass, hiding their faces behind a laptop and book.

Autistic girls are underdiagnosed, writes Altogether Autism researcher Ashe Yee.

Two girls sitting on the grass, hiding their faces behind a laptop and book.Boys are more likely to be diagnosed as autistic compared to girls, with a ratio often reported to be much higher, at least three-to-four boys for every girl.  However, this disparity in diagnosis raises important questions about why many autistic girls have been overlooked by the system and researchers when compared to their male counterparts.  This article will explore some possible reasons for this underdiagnosis, including sex bias in diagnostic measures, differences in the way autism presents in men and women, masking, and a lack of female representation in autism research.

Some studies have observed that autistic girls may exhibit more mutual and non-verbal communication and pay more attention to people’s faces during communication, compared to autistic boys (Rea, Øien, Shic, Webb, & Ratto, 2022). Autistic girls may also display higher levels of cooperation, comfort, larger friend groups, and less shyness than autistic boys, who tend to engage in more solitary behaviours on average.  While autistic girls may still face challenges with forming or maintaining friendships, their behaviour may appear neurotypical to outside observers, especially when compared to boys.  This aspect may contribute to why girls are less likely to be considered for autism diagnoses by the adults in their lives.

Autistic girls may also exhibit behaviours that are more directed inward, from a young age through to adolescence, in contrast to the outward behaviours commonly seen in autistic boys (Rea et al., 2022).  Since inward behaviours are more difficult to detect and may not cause as much distress to others as outward behaviours, the likelihood of autistic girls being referred to diagnostic services is lower.


It is possible that certain features of autism are not inherently different between boys and girls, but rather autistic girls may camouflage or hide their differences more effectively.  This behaviour is commonly known as “masking.”  Masking is a coping strategy that often occurs in social situations, involving copying the behaviours, responses, and expressions of others to fit in, even if it does not feel natural or comfortable for the autistic person to do so (Rea et al., 2022).

Autistic women have compared this experience to playing video games with multiple dialogue options, except in real life, autistic women also need to generate the different responses to choose from.  Masking can be physically and mentally exhausting and can negatively impact the long-term wellbeing of autistic women.  Since social differences play a significant role in autism, successful masking can make autistic girls appear indistinguishable from neurotypical girls, contributing to their lower likelihood of receiving a diagnosis compared to autistic boys. especially when looking back at their personal history (Dean, Harwood, & Kasari, 2016).  As social demands become more complex during adolescence, autistic girls may face more challenges or appear more visibly autistic as masking becomes increasingly difficult.

Not all behaviours exhibited by autistic girls are hidden; some are simply overlooked.  The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) lists “restricted or fixated interests” as part of the diagnostic criteria for autism.  However,  specific interests that autistic girls may show great enthusiasm for, such as horses, dolls, or Disney movies, are often considered expected or missed during diagnosis.  This contrasts with stereotypically “male” interests like trains or road signs, which are usually provided as examples of autistic interests and are deemed more noteworthy from a diagnostic perspective (Allely, 2019).

Sex bias

Unfortunately, the issue of sex bias in the diagnostic process goes beyond interest.  A recent study by Rea et al. (2022) found that the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2), widely considered the gold standard for diagnosing autism, may exacerbate the sex differences in diagnosis by lacking sensitivity in detecting autism in girls.  Autistic girls often present differently to cisgender autistic boys, for whom most diagnostic measures were likely designed. Girls were less likely to demonstrate differences on items related to social-communication behaviours and scored lower on total and subscale scores.  However, when accounting for symptom intensity, the sex differences disappeared.

The authors suggest that diagnostic measures need modifications to more accurately capture the behaviours of autistic females, potentially by adding items or tasks that are more relevant.  Furthermore,  including self-reports from the autistic individuals being assessed provide invaluable insights during the diagnostic process. Clinical assessments rely on the judgements of the clinicians and reports from parents or other adults in the autistic individual’s life, which can be inaccurate if masking or camouflaging behaviours areoccurring.  Incorporating self-reports would give the person being assessed a stronger voice and likely make the process more inclusive and sensitive to the internal expereinces of autistic girls and women.

As a result of the differences in presentation, masking behaviours, and inherent sex bias in diagnostic measures, women often need to exhibit more intense features, greater developmental differences, or also have an intellectual disability to meet the criteria for an autism diagnosis (Frazier, Georgiades, Bishop, & Hardan, 2014).  This explains why many studies report that autistic girls are more likely to have lower IQs or display extreme behavioural problems compared to autistic boys.  It is not that girls have more acute autistic features, but rather they need to experience greater challenges to be noticed. Some professionals still hold an outdated view of autism as a ‘male’ diagnosis, often searching for alternative explanations when girls are exhibit autistic features.  This potential for misdiagnosis that autistic women face will be discussed in a future article.

Fortunately, there are professionals within the diagnostic community who recognise these issues and are working to address them.  In recent years, clinicians have started acknowledging that the ADOS may be less effective in diagnosing autism in girls and interpret the results with caution, particularly when working with clients without intellectual disabilities.  Recognising this limitation, competent clinicians also consider other sources of information, including self-reports, during the diagnostic process.  There is also ongoing discussions among practitioners highlighting the need to reconsider DSM-V criteria to fully capture the diverse facets of autism and its presentations.  Some clinicians have also placed significant emphasis on continuous professional development and competency training related to identifying autism in girls.

Final thoughts

The underdiagnosis of autism in girls is a significant problem that requires attention.  Diagnostic measures need to be more inclusive of the autistic female experience, and the inclusion of autistic women and girls in research, including those with “milder” features, must be prioritised to overcome gender bias is going to be overcome. Professionals from various disciplines need to be more aware of the different ways autism can manifest in girls and recognize that their patients may not fit the traditional autistic mould associated with autistic males, especially when reviewing the patient’s history.  Combating these diagnostic inequalities is essential to ensure every autistic individual receives the recognition and support they deserve.  Only then can we work towards a future where autistic women and girls are empowered, rather than left behind.[/vc_column_text][/vc_column][/vc_row]




Allely, C. (2019). Exploring the female autism phenotype of repetitive behaviours and restricted interests (RBRIs): A systematic PRISMA review. Advances in Autism, 5(3), 171-186.

Dean, M., Harwood, R., & Kasari, C. (2016). The art of camouflage: Gender differences in the social behaviors of girls and boys with autism spectrum disorder. Autism, 21(6), 678-689.

Frazier, T. W., Georgiades, S., Bishop, S. L., & Hardan, A. Y. (2014). Behavioral and cognitive characteristics of females and males with autism in the Simons Simplex Collection. Journal of the American Academy of Child and Adolescent Psychiatry, 53(3), 329 – 340.

Rea, H. M., Øien, R. A., Shic, F., Webb, S. J., & Ratto, A. B. (2022). Sex differences on the ADOS-2. Journal of Autism and Developmental Disorders.


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