controversial theory, autism is the manifestation of an "Extreme Male Brain". The reasoning goes something like this - the condition is far more prevalent in males than females; people with autism think in a distinctive style that's more commonly observed in men than women (that is, high in systematising and low in empathising); and greater testosterone exposure in the womb appears to go hand in hand with an infant exhibiting more autism-like traits in later childhood.
Simon Baron-Cohen, the psychologist who first proposed the theory, always conjectured that there may also be such a thing as an "Extreme Female Brain". Now in a new paper, a pair of researchers in the USA have made the case that the Extreme Female Brain exists, it's highly empathic, and it comes with its own problematic consequences, in terms of a fear of negative evaluation by others, and related to that, a greater risk of eating disorders (which are known to be far more prevalent in women than men).
Supporting their claims, Jennifer Bremser and Gordon Gallup Jr surveyed hundreds of male and female undergrads and found that men and women with more dysfunctional attitudes towards eating, and more fears of being negatively evaluated by others, also tended to score more highly on self-reported measures of empathising. A fear of being negatively evaluated was also associated with lower scores in systematic thinking.
In other words, people with a thinking style more often observed in women, and opposite to that seen in people with autism (high in empathising, low in systematising), tended to be at greater risk for eating disorders and social anxiety.
The results got a bit messier with objective measures. Among female participants, dysfunctional attitudes towards eating were associated with higher scores on an objective measure of empathising, one that involved interpreting emotions from pictures of people's eyes. But for males, dysfunctional attitudes to eating actually predicted lower scores on the test.
The researchers surmised that perhaps these men were over-interpreting the pictures - "hyper-mentalising" - and seeing emotions that weren't there, which would be consistent with their central thesis about the Extreme Female Brain. Supporting this, further studies found that dysfunctional attitudes towards eating and fear of negative evaluation by others also tended to go hand in hand with higher self-reported scores on schizotypy, including exaggerated suspiciousness, magical thinking and paranoia - arguably all signs of "hyper-mentalising", and the opposite of what's seen in autism.
What about objective measures of systematising? Dysfunctional attitudes toward eating and fear of negative evaluation weren't associated with understanding the laws of physics, but they were associated with poorer mental rotation performance scores.
"Evidence from all four studies converge to show that a combination of disordered eating and negative evaluation anxiety are associated with a cognitive style that Baron-Cohen predicted for the Extreme Female Brain," the researchers concluded.
One last thing - Bremser and Gordon Gallup Jr said their ideas suggested a novel explanation for why vegetarianism is particularly prevalent among people with eating disorders. Previously it's been assumed that vegetarianism is popular for this group as a means of calorie restriction. However, if eating disorders are part of the manifestation of an Extreme Female Brain, one that's associated with exaggerated empathy, then vegetarianism may be a natural consequence of having enhanced empathy for animals.
Bremser JA, and Gallup GG Jr (2012). From one extreme to the other: Negative evaluation anxiety and disordered eating as candidates for the extreme female brain. Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior, 10 (3), 457-86 PMID: 22947672
Post written by Christian Jarrett for the BPS Research Digest.