Autism in Girls: Signs, Symptoms and Why It Is Missed

Q: How common is autism in girls?

Autism is less commonly diagnosed in girls than in boys. Research shows that for every 3 to 4 boys diagnosed with autism, only 1 girl is identified. However, many experts believe autism in girls is underdiagnosed because their traits can be more subtle, masked, or different from the typical male presentation. Girls on the spectrum may be better at mimicking social behaviors or hiding their difficulties, which can delay or prevent diagnosis. As awareness grows, more girls and women are being correctly identified and supported.

Q: What are the 3 main symptoms of autism in girls?

The 3 main symptoms of autism in girls are difficulties with social communication, restricted or repetitive behaviors, and intense focus on specific interests - though these often present differently than in boys. Girls may mask their struggles by copying social behaviors, which can make their challenges harder to detect. They might appear socially active but still feel confused in conversations, rely heavily on routines, or become deeply invested in niche topics like animals, books, or fantasy worlds.

Q: What causes autism in girls?

Autism in girls is believed to be caused by a combination of genetic, neurological, and environmental factors similar to boys but it may look different due to how girls often mask their symptoms. Research shows that genetics play a major role, with certain genes increasing the likelihood of autism. Differences in brain development, hormone levels, and immune system function may also contribute. Additionally, girls are often underdiagnosed because they may copy social behaviors more effectively or show subtler signs. Understanding these differences helps improve early detection and support.

Autism in girls has long been talked about far less than autism in boys. One reason is that boys are diagnosed with Autism Spectrum Disorder around 3 to 4 times more often than girls. But researchers now believe many autistic girls are simply being missed, because autism often looks different in girls, and because the tools used to diagnose it were built mostly around boys.

Some Statistics on Autism in Children

Chart comparing autism in girls vs autism in boys, including diagnosis rates

Fig 1: Autism in Girls Vs Autism in Boys

Graphic showing how autism diagnosis rates in children have changed over time

Autism Diagnosis Rates Are Rising, but Girls Are Still Missed

Autism diagnoses have risen steadily over the past two decades. When this article was first written, the US Centers for Disease Control and Prevention (CDC) reported 1 in 88 children; the CDC’s most recent figure is about 1 in 31. Most of this rise reflects better awareness, broader diagnostic criteria and better access to assessment, not a sudden increase in autistic people.

Because autism has been diagnosed far more often in boys, research has mostly focused on boys. That has created a cycle: autism is understood through how it looks in boys, so girls who present differently are less likely to be recognised.

Prof Joan Smith, Researcher, Autism Foundation says, “Unfortunately, most study models are biased towards the male gender as autism is still by and large regarded as a “boys” issue. Until now, we have observed certain behavioral differences among girls with autism, yet the outcome has not been conclusive enough since the volume of research subjects is mostly boys.”

Autistic Behavior in Girls Vs Boys

One of the main reasons autism in girls is missed is that many autistic girls are social. They often want friendships, and many have at least one close best friend. Autistic boys, on the other hand, are more often described as preferring to play alone, which fits the traditional picture of autism.

Based on our experience, the following comparison chart highlights some of the differences, small as some may be, between autism in girls vs boys.

Table 1: Comparison of Autism in Girls Vs Boys

These are some of the differences in social interaction and behaviour that parents can look out for. As the comparison shows, many traits look quite different in girls and boys, which is why diagnosing autism spectrum disorder in girls can be harder.

Autism in Girls Checklist

Common ways autism can look in girls include:

Copying other children closely, or “studying” social rules to fit in (masking)
Intense interests that look typical for their age, such as animals, books, fantasy worlds or a favourite band, but held with unusual depth
One very close friendship, with distress if that friendship changes
Holding it together at school, then meltdowns or shutdowns at home
Strong sensory sensitivities, such as to clothing, noise or food textures
Being seen as shy, anxious or a perfectionist rather than autistic

Diagnostic Challenges for Autism in Girl Toddlers

Apart from conditions like Rett Syndrome, which can be diagnosed medically, autism in toddler girls is often missed. Parents and even doctors may put a quiet, compliant little girl’s differences down to temperament or to girls simply developing differently from boys, rather than considering autism. Girls are often less likely than boys to show their distress outwardly, so their needs can go unnoticed.

Autistic girl, illustrating how long an autism diagnosis in girls can take

Fig 2: In many cases, it can take up to 8 years to Diagnose Autism in Girls

Image of girls with autism, who often don't show obvious signs

Fig 3: Unlike boys, autistic girls may not show obvious signs

The following table highlights the differences in the stages of autism diagnosis for girls and boys.

Table comparing the stages of autism diagnosis for girls and boys

Table 2: Signs of Autism in Children

As the table shows, a boy’s developmental differences are often noticed early and lead to a diagnosis, while a girl’s differences may not stand out until much later.

Chart showing autism in boys is diagnosed far more often than in girls

Fig 4: Autism is diagnosed far less often in girls than in boys

“As low as the numbers are for girls with autism, the numbers of girls diagnosed with Asperser’s is almost nonexistent. The low numbers of autistic girls and the almost rare numbers of girls with Asperser’s might suggest that something in our testing and diagnosing is not focusing on girls with autism. Girls and boys are different at all stages of their life’s progression. Researchers are now looking at those differences to ensure proper diagnosis for girls on the autism spectrum,” comments Mary Alexa, Autism Therapist, Dominican Republic.

Some Common Symptoms of Autism in Girls

Infographic of common signs of autism in girls, such as masking and intense interests

Fig 4: Signs of Autism in Girls

Because young autistic girls often manage well in many areas, a diagnosis can be delayed until late primary school or the early teens, often around age 11 to 13. This is often when parents notice their daughter finding the move into her teens harder than her peers.

Autism in Teenage Girls

She may still be very attached to one close friend and to the imaginative play they shared when they were younger. That friendship can become very important to her, and changes in it can be deeply upsetting, especially if her friend starts to move in new directions.

She may not share her peers’ new interests, like celebrities, fashion or crushes, and may pretend to be interested just to stay part of the group. Puberty and body changes can feel confusing or overwhelming. She may prefer her own interests and the comfort of familiar friendships to the shifting social world of high school.

This can be a hard time, and you may see more distress at home, withdrawal, anxiety or meltdowns. These are signs she needs more understanding and support, not signs she is being difficult. It’s a good time to seek an assessment (our autism tests can be a helpful first step). Talk to your GP or paediatrician about what you’ve noticed, including the things you’d expect to see but don’t.

Prepare for your appointment (read our article on Does my Child Have Autism). The doctor will ask many questions that only you, as the person who knows your child best, can answer. If needed, they will refer your daughter for further assessment.

Remember: positivity is key. Don’t feel that you’ve let too much time slip by. A diagnosis at any age can help your daughter understand herself and get the right support. With the right supports in place, and professionals who understand how autism presents in girls, autistic girls can thrive, build meaningful friendships and grow into confident, independent adults on their own terms.

Related Article: Women Autism and Aspergers Issues.

Other FAQs on Autism in Girls

How common is autism in girls?

Autism is diagnosed less often in girls than in boys. Research shows that for every 3 to 4 boys diagnosed with autism, about 1 girl is diagnosed. However, many experts believe autism in girls is under-diagnosed because their traits can be more subtle, masked or different from the typical male presentation. Autistic girls may be better at copying social behaviour or hiding their differences, which can delay diagnosis. As awareness grows, more girls and women are being recognised and supported.

Is autism more common in boys or girls?

Autism is diagnosed about 3 to 4 times more often in boys than in girls. However, the true difference is probably smaller, because many girls are missed or diagnosed later. Girls often mask their autistic traits and have interests that look typical for their age, so their autism can be harder to spot.

What are the 3 main symptoms of autism in girls

The 3 main symptoms of autism in girls are differences in social communication, repetitive behaviours and routines, and intense focus on specific interests, though these often look different than in boys. Girls may mask by copying social behaviours, which can make their needs harder to see. They might seem socially active but still feel confused in conversations, rely heavily on routines, or be deeply invested in topics like animals, books or fantasy worlds.

What are symptoms of high functioning autism in girls?

Girls with high-functioning autism may show symptoms that are less obvious than in boys, making diagnosis harder. Common signs include strong attention to detail, intense interests (often ones that look typical, like animals or books), sensory sensitivities, finding social cues hard to read, and shyness or social anxiety. They may copy others to fit in, masking their differences. Many also find emotional regulation hard, rely on routines, or have meltdowns when overwhelmed. These traits often become more noticeable in adolescence, as social expectations increase.

What causes autism in girls?

Autism in girls has the same causes as autism in boys: mainly genetics, along with differences in early brain development. Research shows that genetics play a major role, and differences in brain development and hormones may also contribute. Parenting does not cause autism. Autism may look different in girls because many girls mask their traits or show subtler signs, which is why girls are often diagnosed later. Understanding these differences helps improve early recognition and support.

Ash Bhattacharya

I am Ash and I celebrate Neurodiversity! Growing up with an elder brother with severe Autism was tough – but it has also taught me essential life lessons. I don’t believe that people with Autism are necessarily or have any disorder (except in extreme cases). They are just different! And that is something to be proud of! I am passionate about helping other families who may have Autism conditions in their family. So please reach out and drop me a note. I will be glad to help 🙂

Autism in Girls

Some Statistics on Autism in Children

Autism Diagnosis Rates Are Rising, but Girls Are Still Missed