Historically, researchers have viewed autism as a distinctly “male” neurotype, with boys being 10 times more likely to be referred for autism assessments, according to a 2020 review.
In fact, a 2023 study suggests that up to 80% of girls and women may receive a diagnosis of social anxiety, eating disorder or borderline personality disorder before being accurately diagnosed as autistic.
These biases and shortcomings are the subject of Off the Spectrum: Why the Science of Autism Has Failed Women and Girls, a book by brain imaging expert Gina Rippon, who investigates how and why scientists and clinicians have systematically underestimated and overlooked autism in women and girls.
In a 2024 review, Rippon, professor emeritus of cognitive neuroimaging at the Aston Brain Centre in Birmingham, England, found of the more than 120 studies testing brain models of autism that she examined, nearly 70% only tested men or included very few women. She noted that less than 10% of the 4 000 participants in those studies were women.
She was startled to discover the extent to which she and her colleagues had fundamentally misunderstood the nature of autism in girls and women.
She told CNN that because of the very strong belief – up until recently – that autism was a male problem, a massive industry had grown around diagnosis to reliably indicate whether a child had autism.
“But they were only looking at the kind of behaviour that was characteristic of boys. If girls came along with similarly disordered behaviour, the idea that it might be autism just didn’t emerge.”
There were so-called “gold-standard” tests, she added, but because these were based on boys, girls would be screened out.
“For a neuroscientist like me who wanted to look at autism in females, I wouldn’t be able to find any females who had been diagnosed as autistic. It got embedded in our consciousness, ‘Ok, this is a male problem, so we had probably better just look at males’.”
Why is the system biased?
“I like to say the diagnostic dice were loaded from the start. There is no biomarker for autism – there’s not a handy X-ray or some physical test we can use to diagnose autism. Instead, there is a huge array of different behaviours which, over the years, have (been) identified as characteristic of autistic children. But it’s all based on what it looks like in boys.”
She added there was the classic confirmation bias – the tendency to interpret new evidence as a confirmation of one’s existing beliefs.
“Researchers have presented identical hypothetical scenarios to teachers, saying: ‘This child presents with these kinds of issues in the classroom, so do you think the child might be autistic? Do you think this child might need special support?’ Teachers are much more likely to say yes to the notion that the child was autistic and needs support if the child is named Jack than if the child is named Chloe.”
Behavioural differences in autistic children emerge early on.
“Those are times when teachers who have broad experience of a much wider range of children should be able to say, ‘This kind of behaviour is unusual. I think we should take it further’. Instead, if behaviours are unusual and it’s a boy, it’s autism, but if behaviours are unusual and it’s a girl, she’s shy, socially anxious, and people might say, ‘she’ll grow out of it’.”
Autism also presents differently in girls versus boys. Girls who are distressed in some way very often internalise their problems. They become withdrawn and shy, stand in the corner, don’t engage with other children.
“If you’ve got children who are shy and quiet and stand quietly in the corner, you aren’t going to think there’s a problem and maybe you’ll even move on. If you’ve got children who are acting out by banging their heads against a desk or kicking, which is more characteristic of boys, those are the kids you’re going to look at more closely.”
She said the third layer is that there is clear evidence girls try to camouflage or disguise or mask their problems.
“That happens very early on, at age four or five. If you find the right way of asking them questions, they will say, ‘Other people in the class think I’m weird. I try to find out why they think I’m weird, and I try to behave not weird’. I call these kids chameleons.”
This is nothing new, she added. In the 1980s, a researcher named Dr Lorna Wing, who was partially responsible for broadening the notion of autism, said: “Maybe girls are just better at disguising their problems,” and “Maybe girls are taught to behave better earlier on.”
It’s not socially acceptable for girls to act out, so they don’t, Rippon said.
Women she had spoken to for her book said their first reaction on getting a diagnosis of autism was a sense of relief, because it suddenly made so much sense of their lives.
For older women, it was very often then a sense of regret, how different their lives would’ve been if they’d known.
“Particularly the girls who are so desperate to belong… what struck me is how much at odds this is from the view of autism as an aloofness – as if autistic individuals aren’t interested in social contact. With autistic females, it’s almost the reverse. They’re desperate for social contact, but they lack what you might call social instinct, knowing how to behave in social situations.
“Autistic girls could be described as deaf to the language of social behaviour, so they don’t understand how you stand properly or maintain eye contact, or that you aren’t supposed to go on about your favourite subject for an hour. For these girls, a diagnosis can be very freeing and validating.”
Diagnose earlier
On how experts might diagnose autism in girls at an earlier age, Rippon said: “Hypersensitivity to sensory issues like scratchy clothes, bright lights, smells and so on, is more characteristic of girls on the spectrum than boys. And that’s only just come into the diagnosis. It was in the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR).
“Although sensory issues have been very characteristic of autism as a whole, and very often there are reports of autistic children hating loud noises or bright lights or whatever, it wasn’t a diagnostic characteristic until quite recently. Having this in the diagnostic criteria might help.”
She also highlighted raising awareness and accepting that autistic children of both sexes should be allowed special accommodations at school, such as taking tests in a separate room or wearing headphones. “That’s very important.”
Rippon is not a fan of pharmaceutical solutions for young children,” partly because it is a time at which our brains are hugely plastic”.
At the same time, sleep disturbances and gastrointestinal disorders are characteristic among autistic kids, and if left untreated these issues can interfere with social activities.
“There’s a lot about autism you can’t treat. A lot of the behavioural difficulties that autistic individuals have are side effects of their autism; they get hugely anxious because they don’t know how to deal with social situations, not because they need anxiety medication.”
She said it was critical for researchers to speak to autistic people and ask, “What is it like to be you?”
“That perspective is invaluable. There’s a big movement for what is called inclusivity or participatory research, where autistic people become part of the research team.
“They advise what kind of questions to ask, they advise how you might interpret the answers you’re getting. There’s a video I recommend called Here Come the Girls, and in it, autistic women basically say, ‘We are autistic, and this is what it’s like for us’. I think that inclusivity is the future.”
CNN article – Why autism isn’t diagnosed in girls and women (Open access)
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