Autism in Girls: Signs, Masking, and Why It’s Missed

Autism in girls is often missed or diagnosed later than in boys. Many autistic girls copy other children, stay quiet when overwhelmed, and have interests that seem typical, so their difficulties can be hidden. Research suggests about three autistic boys for every girl, not four, meaning some girls who meet criteria are not being identified [1][2].

How common is autism in girls?

In the latest US surveillance data (2022), autism was identified in about 49 per 1,000 eight-year-old boys and about 14 per 1,000 girls, a ratio of about 3.4 to 1 [3]. The World Health Organization’s ICD-11 guidance says males are about four times more likely to be diagnosed [4].

A major meta-analysis of 54 studies looked more closely. Studies that only counted children who already had a diagnosis found a ratio of about 4.5 boys to 1 girl. Studies that actively screened whole populations, finding children whether or not they had been diagnosed, found about 3.3 to 1. The authors concluded the true ratio is closer to 3:1 and that girls who meet criteria are at disproportionate risk of not getting a clinical diagnosis [1].

Why autism in girls is often missed

Masking and camouflaging

Masking (also called camouflaging) means hiding or compensating for autistic differences, such as copying others’ facial expressions, rehearsing conversations, or forcing eye contact. The NHS notes that autistic girls may be more likely to copy how other children behave, stay quiet in difficult situations, and appear to cope socially [2]. A systematic review found evidence for sex and gender differences in camouflaging, and that more camouflaging is linked to poorer mental health, although the research is still developing [5].

In a study of children and teenagers, autistic girls showed similar social reciprocity to non-autistic girls on observation, even though their autistic traits were similar to autistic boys. This suggests girls may look more socially “typical” on the surface [6].

Different-looking interests and behaviors

ICD-11 notes that autistic females tend to show fewer restricted, repetitive interests and behaviors [4]. When they do have intense interests, they may be in areas like animals, a favorite book series, or celebrities, which adults may not see as unusual. A study using clinician and teacher reports found girls met the same criteria as boys but in different ways: they were more likely to hold a back-and-forth conversation and to start friendships, though they struggled to keep them, and their restricted interests were fewer and different [7].

Quieter at school

In middle childhood, ICD-11 notes that boys may act out with aggression when frustrated, while girls tend to withdraw and show emotional changes [4]. Teachers in one study reported far fewer concerns for autistic girls than boys, including about behavior and social skills [7]. A quiet, well-behaved girl who is struggling inside can easily go unnoticed.

Higher bar to diagnosis

A large UK population study of 10- to 12-year-olds found that girls with very high autistic traits were less likely than boys to receive a diagnosis unless they also had intellectual or behavioral difficulties [8]. Screening tools may also work less well: in a large US primary care study, a positive M-CHAT screen was less likely to be followed by an autism diagnosis in girls [9]. Researchers have argued that autism research has been based mostly on boys, so our picture of autism may be biased toward the male presentation [10].

Signs of autism in girls to look for

Autism in girls shows the same two core areas as in boys: social communication differences and restricted or repetitive behaviors. Drawing on NHS guidance and research, the signs may look like this [2][7][5]:

• Copying or “scripting” other children’s play and speech, rather than making up her own.
• One close friend, or friendships that start well but fall apart, often with confusion about why.
• Seeming fine at school but having big meltdowns or shutdowns at home. Parents often call this “after-school restraint”; it is a community term rather than a clinical one, but it is worth telling your doctor about.
• Intense interests that are socially acceptable but unusually deep or all-consuming.
• Strong need for sameness and distress at changes in plans.
• Sensory sensitivities, such as to clothing labels, noise, or food textures.
• Anxiety, low mood, or eating difficulties, sometimes before autism is recognized.

Not every autistic girl masks, and boys can mask too [2]. Some girls show “classic” signs clearly in toddlerhood. US data show that children with profound autism (minimally verbal or with significant intellectual disability) were more likely to be female [11].

Late diagnosis and mental health

Girls are often diagnosed later. In a Dutch study of more than 2,000 people, girls with what was then called Asperger’s syndrome were identified later than boys [12]. Women diagnosed in late adolescence or adulthood describe years of “pretending to be normal” and professionals missing their autism [13].

Autistic people have high rates of anxiety, depression, and other mental health conditions [14], and the NHS notes that autistic girls may be more likely to have anxiety, depression, or an eating disorder [2]. Recognizing autism in girls early means getting the right understanding and support before problems build up.

What you can do at home

• Keep a diary of what happens before and after school, social events, and changes in routine. Patterns of “holding it together” and then collapsing at home are important information.
• Ask your daughter (if she can tell you) how friendships feel, what is tiring, and what she does to fit in.
• Collect reports from teachers, coaches, or childcare, including what they notice in unstructured times like recess.
• Allow recovery time. Quiet time after school can reduce overload, whatever the cause.
• Learn more about how autism is identified in our guide to what happens at an autism assessment.

When to talk to a professional

Speak to your child’s doctor if you see several of these signs, if your daughter is struggling with friendships, school, anxiety, or eating, or if she has a brother or sister who is autistic. Younger siblings of autistic girls had a higher chance of being autistic than younger siblings of autistic boys in a large international study [15]. When you ask for an assessment, it helps to say that you are concerned about masking and to bring written examples. If a first assessment does not reach a clear answer and your concerns continue, it is reasonable to ask for a review or second opinion [16]. See also questions to ask at an autism assessment.

Frequently asked questions

Is autism in girls different from autism in boys?

The core features and diagnostic criteria are the same for everyone. What can differ is how autism shows on the surface. On average, autistic girls may mask more, have fewer or less unusual repetitive behaviors, and withdraw rather than act out when stressed. There is a lot of overlap, and many girls and boys do not fit these averages, so each child needs to be assessed as an individual.

What is masking in autistic girls?

Masking, or camouflaging, means hiding or compensating for autistic differences to fit in. Examples include copying other children, rehearsing what to say, forcing eye contact, and suppressing stimming. It can make autism harder to spot and is often exhausting. Research links higher camouflaging with poorer mental health, so a girl who seems fine in public may still need support.

Why are girls diagnosed with autism later?

Reasons include masking, interests that look typical, quieter behavior at school, fewer teacher concerns, and a long history of autism research focused on boys. Studies suggest girls without intellectual disability or behavior problems are less likely to be diagnosed even with similar autistic traits. Awareness is improving, and clinicians are increasingly trained to recognize how autism in girls can present.

Can autism be diagnosed in teenage girls?

Yes. Autism can be diagnosed at any age. For teenagers, clinicians gather a detailed developmental history from parents, information from school, and the young person’s own description of their experiences. Many girls are first identified in their teens or adulthood, often after anxiety, low mood, or social difficulties lead to an assessment.

References

1. Loomes R, Hull L, Mandy WPL. What Is the Male-to-Female Ratio in Autism Spectrum Disorder? A Systematic Review and Meta-Analysis. J Am Acad Child Adolesc Psychiatry. 2017;56(6):466-474. Link
2. NHS. Signs of autism in children. Page last reviewed 6 May 2026. Link
3. Shaw KA, Williams S, Patrick ME, Valencia-Prado M, Durkin MS, Howerton EM, et al. Prevalence and Early Identification of Autism Spectrum Disorder Among Children Aged 4 and 8 Years – Autism and Developmental Disabilities Monitoring Network, 16 Sites, United States, 2022. MMWR Surveill Summ. 2025;74(2):1-22. Link
4. World Health Organization. Clinical descriptions and diagnostic requirements for ICD-11 mental, behavioural and neurodevelopmental disorders (CDDR). Geneva: WHO; 2024. ISBN 9789240077263. Section 6A02 Autism spectrum disorder. Link
5. Cook J, Hull L, Crane L, Mandy W. Camouflaging in autism: A systematic review. Clin Psychol Rev. 2021;89:102080. Link
6. Wood-Downie H, Wong B, Kovshoff H, Mandy W, Hull L, Hadwin JA. Sex/Gender Differences in Camouflaging in Children and Adolescents with Autism. J Autism Dev Disord. 2021;51(4):1353-1364. Link
7. Hiller RM, Young RL, Weber N. Sex differences in autism spectrum disorder based on DSM-5 criteria: evidence from clinician and teacher reporting. J Abnorm Child Psychol. 2014;42(8):1381-1393. Link
8. Dworzynski K, Ronald A, Bolton P, Happé F. How different are girls and boys above and below the diagnostic threshold for autism spectrum disorders? J Am Acad Child Adolesc Psychiatry. 2012;51(8):788-797. Link
9. Guthrie W, Wallis K, Bennett A, Brooks E, Dudley J, Gerdes M, et al. Accuracy of Autism Screening in a Large Pediatric Network. Pediatrics. 2019;144(4):e20183963. Link
10. Lai MC, Lombardo MV, Auyeung B, Chakrabarti B, Baron-Cohen S. Sex/gender differences and autism: setting the scene for future research. J Am Acad Child Adolesc Psychiatry. 2015;54(1):11-24. Link
11. Hughes MM, Shaw KA, DiRienzo M, Durkin MS, Esler A, Hall-Lande J, et al. The Prevalence and Characteristics of Children With Profound Autism, 15 Sites, United States, 2000-2016. Public Health Rep. 2023;138(6):971-980. Link
12. Begeer S, Mandell D, Wijnker-Holmes B, Venderbosch S, Rem D, Stekelenburg F, et al. Sex differences in the timing of identification among children and adults with autism spectrum disorders. J Autism Dev Disord. 2013;43(5):1151-1156. Link
13. Bargiela S, Steward R, Mandy W. The Experiences of Late-diagnosed Women with Autism Spectrum Conditions: An Investigation of the Female Autism Phenotype. J Autism Dev Disord. 2016;46(10):3281-3294. Link
14. Lai MC, Kassee C, Besney R, Bonato S, Hull L, Mandy W, et al. Prevalence of co-occurring mental health diagnoses in the autism population: a systematic review and meta-analysis. Lancet Psychiatry. 2019;6(10):819-829. Link
15. Ozonoff S, Young GS, Bradshaw J, Charman T, Chawarska K, Iverson JM, et al. Familial Recurrence of Autism: Updates From the Baby Siblings Research Consortium. Pediatrics. 2024;154(2):e2023065297. Link
16. NHS. Autism assessments. Page last reviewed 6 May 2026. Link

This guide is general education, not medical advice. Always talk to your child’s doctor or care team. Last checked: October 2026.