Scientists from the University of Cambridge have completed the world's largest research on typical sexual differences and autistic features. They have tested and confirmed two long-lasting psychological theories: Empathizing-Systemizing Theory of Sexual Differences and Extreme Male Brain Theory of Autism.
Television Channel 4 has tested more than half a million people, including more than 36,000 autistic people. The results were published today in Proceedings of the National Academy of Sciences.
Empathizing-Systemizing theory predicts that women will, on average, achieve greater value than men in empathy tests, the ability to recognize what other people think or feel and to respond to their state of consciousness with the appropriate emotion. Similarly, it anticipates that men will, on average, achieve higher scores on systemisation tests, a system for analyzing or building a system based on the rules.
Extreme Male Spinal Theory predicts that autistic people will, on average, show a masculinized shift in these two dimensions: namely, they will reach lower than the typical population on empathy tests and will achieve the same as not greater than typical populations on systemisation tests.
While both theories were confirmed in earlier research of relatively modest samples, new findings came from a massive sample of 671,606 people, including 36,648 autistic people. They are replicated in another sample of 14,354 people. In this new study, scientists have used very short measures of 10 attitudes of empathy, systematization and autistic properties.
Using these short measures, the team found that in a typical population, women have averaged more than men on empathy, and men have averaged more than women on systemisation and autism on average. These gender differences are reduced by autistic people. For all these autistic results, people were on average "masculinized", ie they had more points on systemisation and autism and lower ratings on empathy compared to the typical population.
The team also calculated the difference (or 'd-score') between the points of each individual on systemization and empathy tests. High d-score means that systemisation of a person is greater than their empathy, and low d-score means their empathy is greater than their systemisation.
They found that in a typical population, men have an average shift towards high d-scores, while women have on average shifted to a low d-score. Autistic individuals, on average, had a shift towards an even higher d-score than typical men. Incredibly, d-scores had a 19-fold greater difference in autistic features than other variables, including sex.
Finally, men had on average higher autistic results than women. Those who work in STEM (science, technology, engineering and mathematics) have on average had higher systemisation and autistic results than those in non-STEM professions. Conversely, those who work in non-STEM occupations, on average, have had more empathy ratings than those who work in STEM.
The paper discusses how important it is to keep in mind that the differences observed in this study relate only to average groups rather than individuals. They emphasize that this information does not speak about a person based on their gender, diagnosis of autism or occupation. To achieve this, it would represent stereotyping and discrimination that the authors strongly oppose.
Furthermore, the authors repeat that the two theories are applicable to only two dimensions of typical gender differences: empathy and systemisation. They do not apply to all gender differences, such as aggression, and the extrapolation of the theory beyond these two dimensions would be a misinterpretation.
Finally, the authors emphasize that although autistic people in the average struggle with "cognitive" empathy – recognizing other thoughts and feelings – they still have intact "affective" empathy – take care of others. It is a common misconception that autistic people are fighting with all forms of empathy, which is untrue.
Dr. Varun Warrier from the Cambridge team said: "These gender differences in the typical population are very clear. From related studies we know that individual differences in empathy and systematization are partially genetic, partly under the influence of our prenatal hormonal exposure, we have to investigate to what extent these observed sexual differences are the consequence of each of these factors and how they interact. "
Dr. David Greenberg, of the Cambridge team, said: "Big data is important for making conclusions that are replicated and robust. This is an example of how scientists can work with the media to achieve a large amount of data."
Dr. Carrie Allison, a Cambridge team, said, "We are grateful to the wider public and the autism community to participate in this research. The next step must be to consider the relevance of these findings for education and support where needed."
Professor Simon Baron-Cohen, director of the Center for Autism Research in Cambridge, who proposed these two theories for nearly two decades, said: "This research provides strong support for both theories, and this research reveals some of the features of autistic people that lead to neurodiversity They are, on average, strong systemisers, which means that they have excellent sample recognition skills, great attention to detail and ability to understand the way we work, and we must support their talents in order to realize their potential – and the welfare of society.