Girls and Autism: The Impact of Gender Bias in Research on Autism

What we know about Autism Spectrum Disorder (ASD) is largely based on research on autistic boys. New studies are telling us how different autistic girls are from their male counterparts.

The issue of gender bias is as antiquated as it is familiar to women around the globe. Despite immense political, social, and economic advances in the last century, aspects of female biology continue to be grossly understudied, contributing to a knowledge gap that permeates the scientific community. This gender disparity greatly looms over the study of ASD, contributing to flawed diagnostic practices that are still used today throughout the medical community and beyond.  

How does the gender gap impact medicine? 

Patients enter a doctor’s office with the assumption that their symptoms will lead to a straightforward medical diagnosis. The treatment for anxiety, seizures, or fatigue will be crafted from decades of reliable scientific research, thoroughly tested to enhance the quality of life for the affected. This ideal is inequitable for women and girls: the vast majority of medical research has been conducted on exclusively male participants. 

Medical trials were banned from including women of “child-bearing age” until the National Institutes of Health’s reform-focused Revitalization Act of 1993, a measure designed to encourage gender and ethnic diversity in research. It took decades for the females to be “substantially” integrated into clinical trials, only reaching the nearly equal participatory sum of 49% in the year 2019 (Feldman, 2019). This figure still exemplifies a “substantial underrepresentation of female participants” in 7 of 11 disease categories, leading to the potential for inexact diagnostic, pharmaceutical, and treatment practices.

This lack of integration can have lethal consequences, a chief example manifesting in the divergent symptoms of heart disease among genders. The Harvard Medical School has described the Heart Attack Gap, the idea that heart disease is vastly “under-recognized as the leading cause of death” among American women, as a self-perpetuating cycle of misinformation.

How did this gap impact the medical development of autism? 

The history of autism is implausibly masculine, exemplified by the absence of girls within the early medical literature. Throughout the dawn of the twentieth century, both Grunya Sukhareva and Hans Asperger, while controversial for different reasons, excluded women from their pioneering works. Even when girls were included in later medical studies, it was at a greatly diminished rate, exemplified by Dr. Leo Kanner’s ratio of three females to every eight males in his World War II-era studies (Spectrum, 2018). 

This lack of visibility in the medical community created the illusion that it is highly unlikely for women to be autistic. While this premise is false, when this history is combined with the overall absence of females from clinical trials, the gender gap in ASD knowledge becomes that much wider. 

An ever-expanding body of research suggests that autism manifests differently in adolescent females than it does in their male counterparts. An innovative 2019 study from the Children’s Hospital of Philadelphia emphasizes that a “historical reliance on predominantly male samples” may have led to “generalizations about narration in ASD that do not apply to girls” (Boorse, 2019). This groundbreaking research provides an opportunity to create an all-encompassing diagnostic protocol for ASD, one that fully explains the differences in symptoms among genders. 

Is there a biological difference in autism by gender? 

There is a strong male bias in the prevalence of autism, given that adolescent boys are four times more likely than girls to be given the diagnosis. There is no definitive biological link to this phenomenon, but contemporary research indicates that some sex hormones, “especially testosterone” may regulate the effects of autism in males (Werling, 2014). The gender gap in autism is likely much smaller than this data indicates, with recent reports asserting that the ratio is likely closer to one female to every three males when appropriate diagnostic procedures are applied. 

Given this body of research, how does ASD differ by gender? 

The following list synthesizes contemporary studies about the gender gap in autism. While the methods, means, and funding of the experiments may vary greatly, each represents an exhilarating opportunity for further study: 

• While both genders use an abundance of nouns in object-focused storytelling, females are more inclined to use cognitive-process words, such as “think” and “know” (Boorse, 2019).
• Females can experience additional difficulty with daily living skills, such as time management when compared with males of the same age and ability level (White, 2017).
• Females are more prone to co-morbid conditions, such as depression and anxiety, than males or neurotypical individuals (Ratto, 2017).
• Prepubescent girls are more likely to engage in social imitative and reciprocal play but may struggle with peer relationships to a greater degree as they age (Rivet, 2011).
• Females are inclined to use consciously acquired physical behaviors, such as pointing and maintaining eye contact, when compared with males of the same age and ability level (Milner, 2019).
• Adolescent boys are more repetitive and singular in play-based activities, while similarly-aged girls hold interests less recurring and more gender-stereotypical in scope (Werling, 2014).
• Females are more apt to camouflage autistic mannerisms than males, who are less inclined to do so across all age ranges (Milner, 2019).

What are the consequences of the gender gap for women? 

The overarching ramifications of the gender gap within ASD diagnoses are unknowable, so long as the voices of undiagnosed women remain lost to the scientific community. Research indicates that individuals who are diagnosed as autistic later in life report feeling “isolated and alien” throughout their childhood, growing up with a negative self-image that “may not change” with medical intervention (Stagg, 2019). When this knowledge is combined with the prevalence of the co-morbid diagnoses of anxiety and depression in autistic women, it becomes that much more critical to shrink the gender gap. 

Autistic girls must have the same opportunity to develop authentic cohorts, supportive resources, and obliging medical care that their male counterparts are likely to receive. True equality can only exist when the scientific community allows for policy to entangle with biology, advancing medical practices for all within the process. 

How can we make the gender gap smaller? 

The global community can begin to bridge this divide through the following methodologies: (Please comment below with any additional ideas!)

• Create groups exclusively for females within the autism community for support and communication 
• Advocate for the government to provide direct funding toward non-discriminatory research opportunities 
• Elevate the voices of autistic females within the media, political, and social landscape 
• Disseminate information about the gender gap in medicine to teachers, caretakers, and clinicians to enhance collective knowledge and awareness 
• Vote for ASD-aligned representatives 

References and Additional Resources:

Autism Data Visualization Tool. (2020, March 25). Retrieved August 05, 2020, from       http://www.cdc.gov/ncbddd/autism/data/index.html

Boorse, J., Cola, M., Plate, S., Yankowitz, L., Pandey, J., Schultz, R. T., & Parish-Morris, J. (2019). Linguistic markers of autism in girls: Evidence of a “blended phenotype” during storytelling. Molecular Autism, 10(1). doi:10.1186/s13229-019-0268-2

Feldman, S., Ammar, W., Lo, K., Trepman, E., Zuylen, M. V., & Etzioni, O. (2019). Quantifying Sex

Bias in Clinical Studies at Scale With Automated Data Extraction. JAMA Network Open, 2(7). doi:10.1001/jamanetworkopen.2019.6700

Hiller, R. M., Young, R. L., & Weber, N. (2015). Sex differences in pre-diagnosis concerns for children later diagnosed with autism spectrum disorder. Autism, 20(1), 75-84. doi:10.1177/1362361314568899

How history forgot the woman who defined autism. (2018, November 12). Retrieved August 02, 2020, from http://www.spectrumnews.org/features/deep-dive/history-forgot-woman-defined-autism/.

Milner, V., Mcintosh, H., Colvert, E., & Happé, F. (2019). A Qualitative Exploration of the Female Experience of Autism Spectrum Disorder (ASD). Journal of Autism and Developmental Disorders, 49(6), 2389-2402. doi:10.1007/s10803-019-03906-4

Publishing, H. (n.d.). The heart attack gender gap. Retrieved August 05, 2020, from http://www.health.harvard.edu/heart-health/the-heart-attack-gender-gap.

Ratto, A. B., Kenworthy, L., Yerys, B. E., Bascom, J., Wieckowski, A. T., White, S. W., . . . Anthony, L. G. (2017). What About the Girls? Sex-Based Differences in Autistic Traits and Adaptive Skills. Journal of Autism and Developmental Disorders, 48(5), 1698-1711. doi:10.1007/s10803-017-3413-9

Rivet, T. T., & Matson, J. L. (2011). Review of gender differences in core symptomatology in autism spectrum disorders. Research in Autism Spectrum Disorders, 5(3), 957-976. doi:10.1016/j.rasd.2010.12.003

Stagg, S. D., & Belcher, H. (2019). Living with autism without knowing: Receiving a diagnosis in later life. Health Psychology and Behavioral Medicine, 7(1), 348-361. doi:10.1080/21642850.2019.1684920

Werling, Donna M.,  Geschwind, Daniel H. (2013). Sex differences in autism spectrum disorders, Current Opinion in Neurology: 26, No, 2. doi: 10.1097/WCO.0b013e32835ee548

White, E. I., Wallace, G. L., Bascom, J., Armour, A. C., Register-Brown, K., Popal, H. S., . . . Kenworthy, L. (2017). Sex differences in parent-reported executive functioning and adaptive behavior in children and young adults with autism spectrum disorder. Autism Research, 10(10), 1653-1662. doi:10.1002/aur.1811