Autism in Girls: Later Diagnosis Than Boys
- Autism spectrum disorder (ASD) is increasingly recognized as presenting differently in girls than in boys, leading to frequent delays in diagnosis.
- For many years, diagnostic criteria and understanding of autism were largely based on observations of boys.
- Girls with autism often exhibit social and communication differences, but these can be more subtle than those typically seen in boys.
Autism spectrum disorder (ASD) is increasingly recognized as presenting differently in girls than in boys, leading to frequent delays in diagnosis. While historically, autism diagnoses have been significantly more common in males, recent research suggests this disparity may be due, in part, to systemic biases in identification and evaluation, and a tendency for girls to be underdiagnosed or diagnosed later in life.
Diagnostic Disparities and the Presentation of Autism in Girls
For many years, diagnostic criteria and understanding of autism were largely based on observations of boys. This has resulted in a diagnostic process that may not adequately capture the ways autism manifests in girls. According to a study led by the Karolinska Institutet in Sweden, and published February 4, 2026, boys are diagnosed with autism on average nearly three years earlier than girls. The median age at diagnosis was , 13.1 years for boys, compared to 15.9 years for girls.
Girls with autism often exhibit social and communication differences, but these can be more subtle than those typically seen in boys. They may be more adept at masking or camouflaging their autistic traits, attempting to fit in with peers by mimicking social behaviors. This masking can involve suppressing natural responses and developing coping mechanisms to navigate social situations, making it harder for clinicians to recognize the underlying autism. As the Child Mind Institute notes, girls tend to be better at hiding repetitive behaviors than boys.
The Impact of Later Diagnosis
The consequences of a delayed diagnosis can be significant. A later diagnosis may delay access to early intervention services, which are crucial for maximizing developmental potential. Girls, especially those without cognitive impairment, may be formally identified at a later age than boys, potentially delaying necessary support. This delay can impact academic performance, social-emotional well-being, and overall quality of life.
The Swedish study, which tracked 2.7 million people born between 1985 and 2020, found that by age 20, diagnosis rates between men and women were almost equal. This suggests that the perceived gender discrepancy in autism prevalence is not necessarily indicative of a true difference in the number of autistic individuals, but rather a reflection of diagnostic challenges. The study authors suggest that the gender difference in autism prevalence is much lower than previously thought, due to women and girls being underdiagnosed or diagnosed late.
Systemic Biases and the Need for Improved Evaluation
Patient advocates emphasize that the research supports arguments that systemic biases exist in how autism is understood and diagnosed. These biases can stem from a lack of awareness among clinicians regarding the diverse ways autism presents in girls, as well as reliance on diagnostic tools and criteria that were primarily developed based on male presentations.
Girls may exhibit different types of special interests than boys. While boys may have intense, focused interests in systems or objects (like trains or dinosaurs), girls may be more likely to have highly focused interests in people, animals, or fictional characters. They may also demonstrate hyper-focus on specific topics, which can sometimes be misinterpreted as simply being shy or quiet, rather than a sign of underlying autistic traits. This can lead to underparticipation in school and a failure to reach their full potential.
Catching Up: Increased Diagnosis in Adolescence
The Swedish research indicates that girls tend to “catch up” in diagnosis rates by the time they reach age 20, owing to a rapid increase in autism diagnosis during adolescence. This suggests that the challenges of recognizing autism in girls may lessen as they get older and their social and emotional needs become more complex, potentially making autistic traits more apparent. However, even with this increase, a delayed diagnosis can still have lasting effects.
boys were three to four times more likely than girls to be diagnosed with autism under the age of 10, according to the Karolinska Institutet study. The research highlights the need for further investigation into why female individuals receive diagnoses later than male individuals. Improved awareness, training for clinicians, and the development of more inclusive diagnostic tools are crucial steps toward ensuring that all individuals with autism, regardless of gender, receive timely and accurate diagnoses and access to appropriate support.