Why are Girls Less Frequently Diagnosed with Autism?

Numbers from the CDC suggest that autism spectrum disorder (ASD) “is more than 4 times more common among boys than among girls.” However, people within the autism community and a growing number of researchers believe the gap between boys and girls is actually much smaller than that. They think other factors might play a role in why girls are diagnosed less frequently, and why many women with autism go undiagnosed.

According to The Autisticats, “Women, trans & nonbinary people are currently and historically underdiagnosed, due to a difference in presentation and masking ability, as well as the fact that most diagnostic criteria is centered around the male-typical presentation of autistic traits.”

Let’s explore why girls with autism may not be diagnosed, or not diagnosed until later in life.

Autism criteria based on studies of boys

Scientific American states the criteria used to diagnose autism spectrum disorder (ASD) is “based on data derived almost entirely from studies of boys.” In other words, when children are evaluated for autism, the criteria used is based on how autism manifests in boys. If girls display different behaviors than what was traditionally observed in boys, it’s likely many girls with autism are not diagnosed.

Behaviors exhibit differently in girls

A 2014 study by the Cleveland Clinic tested  2,418 autistic children, and 304 were girls. The girls were “more likely to have low IQs and extreme behavior problems. This is not to say that autism behaviors are more extreme in girls, but rather, a girl has to exhibit more extreme behavior and lower cognitive abilities to be diagnosed. Girls who behave in a more neurotypical fashion are less likely to receive a diagnosis.

While boys with autism may display specific interests in things like counting or train timetables, girls with autism may be more intensive in their interests. Jennifer O'Toole, the founder of the Asperkids website and company, says, “The words used to describe women on the spectrum come down to the word ‘too’…Too much, too intense, too sensitive, too this, too that.” A girl may have the same interests as her female peers, like playing with Barbies, but she may be obsessed with her Barbies and play with them much differently than other little girls. So, if girls aren’t displaying the specific, expected behaviors of autism, they may be less likely to receive an autism diagnosis than boys.

Autism in girls is diagnosed as other things

Because girls with autism may behave differently than boys, experts believe many girls are likely misdiagnosed with other conditions. They may be diagnosed with attention-deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD) and sometimes, eating disorders. Instead of being diagnosed with ASD, their intense focus on washing their hands or counting calories is interpreted as something else. This doesn’t mean that these same girls don’t have BOTH an eating disorder and autism, but the focus on one allows the other to be missed. Many individuals with autism have co-occurring conditions, like autism and anxiety.

Girls are better at masking symptoms

It is also believed that girls may be better at masking behaviors. An Australian study comparing boys and girls with autism found little girls were “more likely than boys to mimic others in social situations and to want to fit in with other kids.”

“This is likely due to gender-based expectations girls and women experience,” says Jael Jaffe-Talberg, Fraser pediatric clinical psychologist. “They are socialized to ‘act like a girl’ and experience greater pressure to censure their own behaviors.”

Adult women with autism, who were diagnosed late in life, also report that they learned to study other people to know how to act socially.

Brain differences may also play a role

Research also suggests that the brains of girls with autism function differently than those of boys with autism. Scientific American states, “Each girl's brain instead looks like that of a typical boy of the same age, with reduced activity in regions normally associated with socializing.” So the girls with autism have different brains than other girls their age, but their brains are similar to boys of their age without autism. In other words, if these same girls were boys, they wouldn’t be diagnosed with autism. This certainly would explain why many girls go undiagnosed.

Girls with autism are better at masking it, may act differently than autistic boys and have different brains than their autistic male peers. Additionally, girls are evaluated with criteria based entirely on how autistic boys’ behaviors. It’s no wonder fewer girls are diagnosed with autism.

And yet, the more we learn about autism, the more girls and women receive a diagnosis. If you think your child might have autism, reach out to your pediatrician or contact a Fraser expert to schedule an autism evaluation.