Monday, 1 October 2012

Are eating disorders the manifestation of an "Extreme Female Brain"?

According to an influential and 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.


Paul Whiteley said...

Interesting post.

Aside from mentioning the name Cordelia Fine regarding the whole sexualisation of brain and behaviour and the sweeping generalisations that have accompanied it:

there is another variable in this relationship when it comes to looking at autistic traits and the extreme female brain.

Work by Oldershaw and colleagues for examples suggests that on measures of empathy, the cognitive profile of eating disorders (diagnosed) like anorexia nervosa generally speaking are more similar to that of autism than different:

There could be some differences in terms of formal diagnosis of an eating disorder and the participants described by Bremser & Gallup but I would hedge my bets that more likely the anxiety side of things is the important variable in their study over and above eating disorders.

Possible also that in cases of diagnosed AN, the autistic traits link is more strongly associated with the obsessionality that accompanies eating disorders perpetuating symptoms.

I wonder also whether self-monitoring might also play a hand in these and other results??

Unknown said...

hi Paul, thanks for these v. useful thoughts and references. I've made the word "controversial" in the blog post click through to Cordelia's article.

Professor Keith R Laws said...

I wish we would move away from adding 'brain' to either the word 'male' or now the word 'female' - its total unfounded category error. There is no assessment of the brain in this study and next to none in studies of the so-called 'male brain' and autism - extreme male brain is assessed using Baron-Cohen's systematising/empathising questionnaires. Its measuring some aspect of personality (if anything) and nothing to do with the brain- would we we feel equally justified in replacing every instance of the word 'personality' with the word 'brain' - whats my Big Five Brain?

Scott McGreal said...

Thanks for posting this article Christian.
I am concerned about the inconsistent way the authors interpreted the results regarding the Reading the Mind in the Eyes and disordered eating. The results for males seem to contradict their hypothesis, yet they then argue that this actually confirms their theory on the grounds that male failure to correctly identify emotions was a sign of "hyper-mentalizing". If this kind of reasoning is accepted, the results could be interpreted to mean anything the authors want and their hypotheses would then be impossible to disconfirm. Their results shown in figures 1 & 2 suggest that in females, disordered eating is unrelated to EQ or mind reading, but in males disordered eating is associated with higher EQ but poorer mind-reading. A reasonable interpretation is that disordered eating in females is unrelated to empathising and hence the hypothesised association with the "extreme female brain" is unwarranted. The results for males suggest an association of disordered eating with higher self-reported empathising but lower actual ability to accurately detect emotions. Perhaps this is some sort of deficit of self-understanding in these males, but whether this should be construed as a "female typical" pattern seems questionable, since females themselves did not show it.
The authors go on to discuss connections between schizotypy and disordered eating. I do not find it surprising that odd beliefs and magical thinking would be associated with disordered eating but I am much less clear how schizotypy relates to Baron-Cohen's model. They try to argue that belief in telepathy is an example of "hyper-mentalizing" associated with the EFB but I am concerned that they are again trying to have it both ways. The schizotypy scales were mostly unrelated to EQ, and the few significant associations were negative. The authors' idea of what would constitute evidence for an EFB seems to be so elastic that nearly any pattern of results could be made to support it. I think there are some interesting findings, but I find their theorising to be less than rigorous. Sorry if I have gone on for too long!

Unknown said...

Hi Scott - Thanks for your interesting comments. I agree with you, it is somewhat troubling that the negative finding in males is interpreted as supporting the hypothesis via the idea of "hyper-mentalising". The only thing I'd question in what you said is that you noted that in females disordered eating is not related to the "reading mind in the eyes test" (rem). According to the researchers, higher scores on disordered eating in females tended to correlate with better performance on the rem test (see the start of second paragraph on p. 472).

Tetyana said...

I think calling any behavioural or neurobiological phenotype as an "extreme female brain" is really, I don't know.. it rubs me the wrong way. So unspecific, and almost sounds like pseudoscience. (I'm not saying it is, but it sounds like it.)

I find that the hypotheses or the conclusions the researchers make based on the data to be a little inflated.

Maybe I'm really not getting something (I didn't read the post *too* carefully), but if the EFA is the opposite of the EMB (ie, ASD, or ASD features), then how does this square with the findings that AN and ASD have similar neurocognitive profiles? Wouldn't AN, then, be more like the EMB? Essentially, this goes directly against Oldershaw and others who are pushing the idea of some shared genetic etiology in AN and ASD.

I think that it would be useful, and necessary, I feel, to make sure we don't lump all EDs into one. I think EDs characterized by bingeing and purging are different from predominantly restrictive types. It is all a continuum, but I think it is useful to group them like that for studies of neurocognitive profiles, etc.. because there are a lot of differences if you compare patients with BN and those who've only had restricting type AN for 5+ years, for example.

Anyway, I don't buy this idea. Especially the idea that patients with EDs are more likely to "hyper-mentalize". I highly doubt that. Also, what about the 10-20% of ED patients that are male? Maybe I'm biased, I consider myself a skeptic, and someone who strives to think critically about information that I read or hear (and not magically), but I have an eating disorder. (I know, I know, anecdotal, but this hypothesis seems very specious.)

I don't buy this at all:
"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."

Unknown said...

Womenhood has existed before culture. Easting disorders are a product of culture- as is gender. Testosterone- autism link, not gonna argue with it. But the supposition of its opposite is based on gender stereotypes, which also produced the heightened pressures on women and many others- to acheieve a certain body ideal, causing them to resort to extreme measures as their mental and emotional health deteriorates. More science is needed here.

Anonymous said...

I completely agree with this statement. Yes, there might be correlations between the "female brain" and eating disorders due to the pressures of today's society, but more science is needed to go as far as saying it has to do with the functioning of the female brain. Also, as far as the male brain, testosterone, and autism link I'm not going to disagree, but I feel more research is going to be needed over the years to truely determine whether this is true or not. I believe these ideas/predictictions might be headed in the right direction, but I would not go as far as to say that they are completely true.

psychology said...

great article..i have learned something,i just knew it right now..and i am glad that i have found your site,its very helpful to me..

Cavall de Quer said...

There's quite a lot of material around to back up the last paragraph: for instance - surprise, surprise ;)

Anonymous said...

As a teacher of Psychology I love this for all the reasons I hate it as an avid digester of research. The lack of a scientific approach, the inappropriate brain-based conclusions as well as the social sensitivity for males with eating disorders certainly has the potential to provoke an excellent discussion in the Psychology classroom but unfortunately seems to do little to promote progress in Psychology.

internal medicine said...

This is interesting and I'm happy that I learned something new. I'm just wondering if this is another gender bias.

sarah said...

Eating disorders exist irrespective of a pressure to achieve a 'body ideal'.

Anonymous said...

Where can I read the whole paper? Can only find the abstract on PubMed. Great summary here!

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