12/08/2020
Autism is an extremely complex condition which affects people in different ways. It manifests in difficulty reading and relating to others; restricted and repetitive behaviours; and in differences from the 'neurotypical' population in memory formation and in processing sensory information. There is at present no biological test for autism, but a test based on behavioural criteria.
At an incidence of 4:1 male to female, autism has primarily been seen as a male condition, and Hans Asperger, who first theorised the condition in 1938, initially thought it was exclusive to males. Autism rates have been rising as the condition has gradually been better understood, however: over the last eighteen years, diagnoses have risen threefold in the United States, according to the Center for Disease Control and Prevention.
With âhigher-functioningâ forms of autism â a term that relates to higher IQs and greater ease adapting to the norms of the world we live in â the incidence is higher still, at 10:1 male to female, raising important questions about autism's relationship to s*x and gender, and why it is that so few women have been seen to have autism.
Men do seem to have a higher predisposition to developing autism. Male foetuses seem to be more vulnerable to health problems in general. They have a higher mortality rate and are more prone to a range of health issues â ear infections, for instance. Meng-Chuan Lai, director of gender research at the Autism Research Centre in Cambridge, says this vulnerability may result from hormonal disturbances related to s*x differentiation, immunological development, and development of the gut microbes â all mechanisms thought to relate to the development of autism.
Alycia Halladay, chief science officer of the Autism Science Foundation, proposes there may also be a âfemale protective effectâ. âGirls with autism certainly have a higher genetic load,â Halladay says. âSo you actually see more genetic mutations in girls with autism than you see with boys with autism,â implying that girls are protected genetically.
A lot of early research into autism was undertaken by Simon Baron-Cohen in the late 1980s. Baron-Cohen, who is director of the Autism Research Centre, is responsible for the âextreme male brain theory of autismâ, suggesting that high levels of foetal testosterone â to which male infants are more exposed â predicted poor eye contact, poor social relationships and a lack of empathy, as well as a greater aptitude for working with patterns, systems and objects, as opposed to people.
The theory is that people with autism are late to develop a âtheory of mindâ â assessing and responding to othersâ emotional states â and have average to above average abilities understanding systems and machines with routine outputs, which are, according to Baron-Cohen, predominantly male characteristics. Autism, Baron-Cohen says, is an extreme expression of male biological predispositions.
In 2003, Baron-Cohen extended his autism research into a broader theory arguing that men and women are wired differently, and that these essential differences mean men are more attuned to the workings of systems and women to people and emotions.
âLeaving aside political correctness, there is compelling evidence for s*xual dimorphism [binary difference between men and women] in the brain, cognition, and behavior... We conjecture that understanding s*x differences in the general population has implications for understanding the causes of autism-spectrum conditions,â wrote Baron-Cohen along with coauthors Rebecca Knickmeyer and Matthew Belmonte in 2005. Baron-Cohen argues that males perform better in spatial navigation, where girls are more verbal earlier, and boys prefer playing with mechanical toys where girls elect to play with dolls.
Baron-Cohen says that his 2003 book The Essential Difference explained his âposition was not an extreme biological determinist one, nor an extreme social determinist one... but is an interactionist and in [his] view moderate position.â That this terrain is fraught, he says, âspeaks to the political sensitivities surrounding any gender research in psychology and neuroscience,â but affirms his position âthat some gender differences in the mind and brain may be the result of an interaction between prenatal biology and experience.â Speaking to WIRED, Baron-Cohen said he "can understand this sensitivity, after centuries of historical discrimination against women, but we need to separate science from politics.â
His research has, however, come in for criticism. Neuroscientist Lise Eliot, who reviewed Baron-Cohenâs work on the extreme male brain theory and his theory of psychological s*x differences in Pink Brain, Blue Brain, says the data to support the idea that testosterone determines brain differences in men and women âwere extremely weakâ â both in those with autism and in the wider population. âYouâd also find a correlation between foetal testosterone and whoâs wearing pink or blue Pampers, but that doesnât mean the relationship is causal,â she writes.
Eliot, along with Sarah Richardson at Harvard University, questions the validity of investigating less complex mammals in the context of s*x brain differences. In humans, disparities associated with gender âhave a strong sociocultural componentâ which is extremely âchallenging to model in animals,â if not impossible. Their research questions institutional requirements to investigate s*x using animals, arguing it skews research and âentrenches the presumption that human brain and behavioral differences are largely biological in origin,â overlooking "potentially more powerful social, psychological, and cultural contributors".
Eliot draws attention to a widely-cited 2000 study by Baron-Cohen which looked at 102 newborn babies to see whether boys and girls spent the same amount of time looking at a mobile or a live human face. In this small study, boys spent 52 per cent of their time looking at the mobile and 46 looking at the face, while girls split their time 41 and 49 per cent between the mobile and the face. This was heralded as evidence âbeyond reasonable doubtâ that s*x differences are innate. Yet other studies fly in the face of these findings, observing more time spent on faces by boys than girls, or more toy-time by both boys and girls.
Indeed, across the population, Eliot says, "the differences between men and women on average are very subtle, but there is this one major difference, which is that menâs bodies and brains on average are about ten per cent larger than females.â This difference in size, though, has been shown not to confer noticeable differences: âonce you take account of brain size differences, almost all the other differences dissolve,â she says.
Eliot emphasises that research into autistic traits cannot be separated from wider considerations of how personality itself develops, especially in the context of gender, and that investigations into the role played by s*x and apparent âbiologyâ are extremely difficult to undertake because of the intense plasticity of the human brain and the lasting impact of gendered socialisation which takes place from the moment babies arrive. âWe say weâre looking at s*x differences but what weâre really looking at, with boys and girls, men and women, are gender differences, because being born and labelled male or female changes oneâs social and communicative experience from birth,â Eliot told WIRED.
For instance, itâs been documented that âmothers talk more to their daughters than to their sons,â which may contribute to girlsâ better communicative development, and while there are differences in girlsâ and boysâ eye-contact by four months old, there are none at birth, according to a 2004 study. âEarly social development is rapid and intense and has â presumably â long-lasting implications if you think about the way the brain is built, and the way the initial connections are formed are going to lay the groundwork for all the later circuitry,â Eliot says.
The brain's synaptic density, for instance, quadruples in the first year of life, attesting to the sheer concentration of development in these early months and years. Because of how early they are born and how long their period of development relative to similar-sized mammals, human infants are extremely impressionable, depending upon intensive interaction for survival. Eliotâs work contends that disruption in these developmental process may provide a key insight into the development of autism, with implications for how we gender babies.