Largest-Ever Study of Gender Differences in Autism
Researchers at the University of Cambridge in the U.K. have conducted the world’s largest-ever study investigating the psychological differences between males and females with autism.
The study, published in the Proceedings of the National Academy of Sciences, tested and confirmed two long-standing psychological theories: the Empathizing-Systemizing theory of sex differences and the Extreme Male Brain theory of autism.
The Empathizing-Systemizing theory posits that women tend to score higher than men on tests of empathy, the ability to recognize what another person is thinking or feeling, and the ability to respond to their state of mind with an appropriate emotion. On the other hand, men tend to score higher on tests of systemizing, the drive to analyze or build rule-based systems.
The Extreme Male Brain theory predicts that, on average, people with autism will exhibit a masculinized shift on these two dimensions: They will score lower than the typical population on tests of empathy and will score the same as, if not higher, than the typical population on tests of systemizing.
“This research provides strong support for both theories,” said Professor Simon Baron-Cohen, Director of the Autism Research Centre at Cambridge who proposed these two theories nearly two decades ago.
“This study also pinpoints some of the qualities autistic people bring to neurodiversity. They are, on average, strong systemizers, meaning they have excellent pattern-recognition skills, excellent attention to detail, and an aptitude in understanding how things work. We must support their talents so they achieve their potential — and society benefits too.”
While both theories have been confirmed in prior studies of relatively modest samples, the new findings come from a massive sample of 671,606 people, 36,648 of those with autism. The research team worked with the help of the television production company Channel 4.
The findings were then replicated in a second sample of 14,354 people.
“Big data is important to draw conclusions that are replicable and robust. This is an example of how scientists can work with the media to achieve big data science,” said researcher Dr. David Greenberg from the University of Cambridge.
In the study, the scientists used very brief 10-item measures of empathy, systemizing, and autistic traits.
Using these measures, the researchers found that in the typical population, women, on average, scored higher than men on empathy, and men, on average, scored higher than women on systemizing and autistic traits.
“These sex differences in the typical population are very clear,” said Cambridge researcher Dr. Varun Warrier. “We know from related studies that individual differences in empathy and systemizing are partly genetic, partly influenced by our prenatal hormonal exposure, and partly due to environmental experience.”
“We need to investigate the extent to which these observed sex differences are due to each of these factors, and how these interact.”
As suspected, these gender differences were reduced in individuals with autism. On all measures, the scores of those with autism tended to be more “masculinized;” that is, they had higher scores on systemizing and autistic traits and lower scores on empathy, compared to the general population.
The researchers also calculated the difference (or d-score) between each person’s score on the systemizing and empathy tests. A high d-score means a person’s systemizing is higher than their empathy, and a low d-score means their empathy is higher than their systemizing.
In the typical population, men, on average, had a shift towards a high d-score, whereas women, on average, had a shift towards a low d-score. Those with autism, however, had a shift towards an even higher d-score than typical males. Strikingly, d-scores accounted for 19 times more of the variance in autistic traits than other variables, including sex.
Finally, men in general tended to have higher autistic trait scores than women. Those working in STEM (Science, Technology, Engineering and Mathematics) had higher systemizing and autistic traits scores than those in non-STEM occupations. And conversely, those working in non-STEM occupations showed higher empathy scores than those working in STEM.
In the paper, the authors say it is important to keep in mind that differences observed in this study apply only to group averages, not to individuals. They emphasize that the data say nothing about an individual based on their gender, autism diagnosis, or occupation. To do that would constitute stereotyping and discrimination, which the authors strongly oppose.
In addition, the authors reiterate that the two theories are applicable to only two dimensions of typical sex differences: empathy and systemizing. They do not apply to all sex differences, such as aggression, and to assume the theories go beyond these two dimensions would be a misinterpretation.
Finally, the authors highlight that although individuals with autism often struggle with “cognitive’ empathy” — recognizing other people’s thoughts and feelings — they nevertheless have intact “affective” empathy, in that they care about others. It is a common misconception that those with autism struggle with all forms of empathy.
Source: University of Cambridge
Pedersen, T. (2018). Largest-Ever Study of Gender Differences in Autism. Psych Central. Retrieved on May 26, 2020, from https://psychcentral.com/news/2018/11/19/largest-ever-study-of-gender-differences-in-autism/140509.html