If you were asked to describe an autistic person, you might find it easy to think of an example, whether a relative, a colleague or even yourself. Diagnoses for autism have risen roughly tenfold over the past few decades, and a suite of broader diagnostic criteria means it now seems simpler to recognise in each other or ourselves. To the autistic stereotypes that dominated popular culture until recently – ’s numerical savant Raymond Babbitt or ’s idiosyncratic physicist Sheldon Cooper – are now added women, like the detail-oriented detective Astrid Nielsen and the fierce chess champion Beth Harmon in The Queen’s Gambit.
It’s a world away from the early 2000s, when psychologist Simon Baron-Cohen proposed his “extreme male brain” concept of autism. Since it was first defined in the 1940s, autism had been considered a condition that largely affects men, a view that Baron-Cohen, the world’s most prolific autism researcher, cemented with his focus on autistic people who score particularly highly for systematic thinking and lowly on some aspects of empathy.
But today, Baron-Cohen and other autism researchers find themselves at a crossroads. In recent years, the proportion of boys and men diagnosed with autism has markedly fallen compared with girls and women. Meanwhile, there’s growing evidence that autistic people may not lie on a single spectrum with extreme cases all at one end, but within multiple distinct subtypes. So, where does this leave the ideas developed by Baron-Cohen in over 1000 highly cited papers and three popular science books?
“Headlines can be misinterpreted,” Baron-Cohen tells me as we sit down in his office at Trinity College, University of Cambridge, where he has been a fellow since 1995, to discuss how his ideas, which have garnered much media coverage, have fared. “I try to do a bit of myth-busting.” Nevertheless, he has recently rolled back on the term “extreme male brain”, describing it as an unhelpful label – although he still stands by the core ideas that underpin it.
Baron-Cohen didn’t set out to make autism about sex. For him, it all began with the concept of empathy. Working in the 1980s at a pioneering school that offered one-on-one education for autistic children, he wanted to better understand their behaviour, especially their seeming lack of social awareness. “A child could come right up close to your face without any embarrassment,” he says. “Or a teenage autistic girl might walk into their parents’ dinner party with no clothes on, but with no embarrassment.” This led him to conversely wonder why non-autistic children develop a sense of self-awareness and worry what other people think of them.
Systemising versus empathy
Searching for answers to questions like these, a few years later, he completed his PhD at University College London under the supervision of renowned psychologist Uta Frith. And over the next decade, he designed experiments to test autistic children’s understanding of a whole range of mental states, such as intentions, desires, emotions and perceptions. In 1995, he coined the term “mindblindness” to describe the seeming difficulties autistic people have understanding what’s going on in someone else’s head.
Mindblindness has sometimes been misunderstood to mean that autistic people aren’t empathetic. But in a 2004 paper, written with Sally Wheelwright, then also at the University of Cambridge, Baron-Cohen argued that, when measuring someone’s empathy, we need to consider two kinds: cognitive empathy, which is the ability to recognise what someone else is thinking, and affective empathy, which layers the appropriate emotional response on top of that understanding. Autistic people, he says, seem to struggle with cognitive empathy, but not affective empathy, which may even be heightened. “If you tell an autistic person that somebody else is suffering, it upsets them – they want to go over and help,” he says. This is the mirror opposite of psychopaths, who tend to have good cognitive empathy but lack affective empathy.
Beyond this, Baron-Cohen couldn’t help feeling that researchers, himself included, were too narrowly focusing on the negative aspects of autism. From the early 1990s, with the widespread adoption of Asperger’s syndrome as a diagnosable form of autism without intellectual disabilities, there was a growing awareness that the condition could come with unique gifts. (Asperger’s syndrome is no longer an official medical diagnosis.)
A classic example might perhaps have been Isaac Newton, a man of obsessive interests who struggled socially but also laid the foundations of modern physics. “We can’t know for sure that he was autistic,” Baron-Cohen told me earlier that day, while gesturing towards a statue of Newton in the chapel at Trinity College, where Newton was also once a fellow. But his relationships with other people were often challenging, he tells me: for years, Newton lectured to an empty room because so few students could understand him.
Newton does seem to fit the pattern of someone with social difficulties combined with a gift for maths, music, drawing, jigsaw puzzles – or really anything not to do with the social world. Baron-Cohen’s leap was to encompass all these kinds of upsides to autism in one idea. “I came up with an umbrella concept: systemising.”
This natural drive to analyse, understand, predict and construct rule-governed systems is a distinct way of processing the world that comes from deep within, he says. “I see it as almost akin to a spider spinning a web. No one’s told it to do that. It’s just what it does.”
Walking back across the courtyard from the chapel towards Baron-Cohen’s office, he points up to a window. “Those were Wittgenstein’s rooms.” Philosopher Ludwig Wittgenstein – arguably another extreme male brain stereotype – devoted much time searching for the logical rules of human behaviour rather than relying on intuition. “Maybe for him that was his natural approach to trying to understand other people’s minds,” he says.
Speculative examples like these suggest an imbalance that became the core of Baron-Cohen’s definition of autism. When we reach his office, he pulls a book off the shelf and points to a graph with empathising along one axis and systemising along the other. “The human mind has these two different types of architecture, which evolved for very different purposes,” he says. “One is to navigate the social world and the other one is to navigate the non-social world.”
The idea behind the graph is that anyone can take psychometric tests, designed by Baron-Cohen, that rate their empathising and systemising abilities. These tests tend to find that autistic people lack aspects of empathy and are excellent at systemising. As a result, autistic people tend to cluster in one region of the graph. He also found a similar pattern among non-autistic males compared with females – although to a lesser extent. Prompted by these findings, in 2002 he wrote that autism can be considered an “extreme” of the normal male profile when it comes to empathising and systemising. The graph he shows me is from his popular science book, published the following year, entitled The Essential Difference: Men, women and the extreme male brain.
Rising diagnosis among women and girls
Controversy has surrounded Baron-Cohen’s extreme male brain theory of autism ever since. For one, the idea appears to reinforce gender stereotypes, suggesting that men are more inclined towards analytical thinking while women are more empathetic. By considering autism as a form of extreme maleness, it also hints that the condition is less common in women and girls.
“I’m still quite shocked by the misinterpretations. Some people think that the theory says that if you’re female, you can’t be autistic,” he says. “In all of these books and articles that I’ve written, it never says that.”
Granted, Baron-Cohen has been clear in his work that not all men have a “male brain” type and not all women have a “female brain” type – this is no Men Are from Mars, Women Are from Venus, he writes in . His hypothesis focuses on patterns seen by comparing large numbers of men and women, but it doesn’t exclude the reality that people vary widely within each biological sex, not just between them.
But when I ask him if he regrets coining the “extreme male brain”, he stands by the idea that autistic people show an extreme of a “typical” male profile when it comes to the two dimensions of empathy and systemising.
Some see this sex-inflected view of autism as directly harmful. Psychologist Gina Rippon has argued that using a male profile to build diagnostic criteria for autism led to the condition being systematically missed or misdiagnosed in women and girls. That has been changing as, over the past two decades, the ratio of male-to-female autism diagnosis has dropped from 4:1 to around 3:1 in children under 10 years old – and in some studies, this ratio almost reaches parity by adulthood.
Baron-Cohen doesn’t think the extreme male brain theory was to blame – noting that the rates of diagnosis of women and girls took off around the same time as he was developing his ideas. “The social pressures on females to mask or camouflage, likely for reasons to do with stigma surrounding autism in females, is a much more likely explanation for why autism went underdiagnosed or misdiagnosed in females,” he says.
Still, Baron-Cohen doesn’t think the male-to-female ratio will ever reach parity. “More girls have come forward seeking a diagnosis and that’s good. But the fact is that there seems to be a higher likelihood of ending up with a diagnosis of autism if you’re male,” he says.
Sex hormone theory
Although Baron-Cohen no longer stands by the extreme male brain label, he says there is more evidence than ever for the empathising-systemising framework – pointing to a 2018 paper he co-authored, based on online tests taken by 670,000 people, which confirmed many of its predictions.
What’s more, this framework of how the autistic mind works is underpinned by another of Baron-Cohen’s ideas: the prenatal sex steroid theory of autism. Research, including his own, has found that biological differences in a fetus’s exposure to sex hormones are linked to autistic traits years later. And studies on animals and “organoid” clumps of brain tissue find that patterns of sex hormone exposure alter the brain’s architecture in ways that may be indicative of autism.
On the face of it, these studies support the idea that male and female sex differences are instrumental in autism. Yet it would be a mistake to view autism only through this binary, says Baron-Cohen. “These days, we don’t think of sex or gender as a binary because there’s lots of different shades.” Indeed, his 2018 paper found that non-binary people were 5.5 times more likely to be autistic.
All of which lays bare a paradox at the core of autism research. To better understand the condition, we need simplified ways to distinguish or define it – and Baron-Cohen successfully developed one such way. But in defining autism along certain lines, you have to cut through the complex biological and social factors that are involved, which may exclude people as a result.
Baron-Cohen acknowledges that his prenatal sex steroid theory of autism can only partially explain autistic differences in empathising versus systemising. “These aspects of the brain are not just influenced by hormones but also genetics – and these all interact.” Likewise, differences in empathising versus systemising are far from an exclusive definition of autistic traits. “There will undoubtedly be other dimensions that are relevant,” he says. “For example, sensory sensitivity, IQ, language, executive function and co-occurring conditions.”
Autism subtypes
The more we look at alternative ways of assessing and comprehending autism, the larger the club becomes. In Sweden, autism diagnoses rose tenfold between 2000 and 2022, for example. There are similar trends in many countries because of greater awareness of the condition, but also because of a broadening of how we define autism. So, how do we move forward in making sense of this increasingly nebulous condition?
Baron-Cohen sees hope in mounting evidence that there are multiple kinds of autism. These subtypes are based on patterns in genes, brain activity and traits found in studies with large populations of autistic people. He sees his own theories of autism as compatible with subtyping and suggests we may well find a common underlying thread that ties together all subtypes. “Subtyping autism is urgent both to make scientific progress and to provide tailored support to autistic people and their families,” he says.
He reflects on the progress made in supporting the autistic communities he first met in the 1980s. “The field has come a long way since then and the priority for all autism research is to serve the autism community… the goal must always be their better quality of life,” he says.
Asking autistic people what they want and need is a cornerstone of research at the Autism Research Centre, which Baron-Cohen founded at the University of Cambridge in 1997. As well as involving autistic people, or their parents, in the design of studies, the centre’s red lines are clear. “We’re explicit about how we’re not looking for a cure for autism, for example, or we’re not trying to develop a prenatal test for autism,” he says. Similarly, he wants to find ways to allay the fears of autistic communities that subtyping could be used to divide them and allocate resources in unequal ways.
This participatory approach has paved the way to some surprising results from population studies involving thousands of autistic people. “It turns out that many autistic people have got many co-occurring mental or physical health conditions,” he says. Some of these conditions, such as heart disease or polyendocrine metabolic ovarian syndrome, involve hormones like testosterone and may well have a basis in Baron-Cohen’s prenatal sex steroid theory of autism. Others, like hypermobile joints, are much harder to make sense of through this lens, he says.
Regardless, findings like these have immediate relevance for how best to support autistic people, says Baron-Cohen. “If you’re a [doctor] and you’ve got an autistic person as your patient, what else should you be asking? What should you be looking for?” he says.
“It’s trying to open our minds to the fact that just because autism is diagnosed on the basis of, say, social difficulties, repetitive behaviour or narrow interests, actually autism may come with a lot of other things.”