Evolution of anorexia

There are many theories out there as to what causes eating disorders--perhaps even more theories than there are people to profess them. Some of them are opinion, some of them are based in science, and some of them incorporate both. When I first read of Shan Guisinger's "Adapted to Flee Famine" hypothesis on anorexia, I will admit that I thought the woman was a little cracked. Guisinger hypothesized that the traits so problematic in anorexia nervosa--an ability to go for long periods without eating, hyperactivity--could actually be beneficial during famine, as people could either escape their immediate surroundings to find food, or search longer and wider for food to bring back to the group. Which, from an evolutionary standpoint, did make sense: people with these genes would be more likely to survive a famine, therefore, they would be preserved in the gene pool.

What I didn't get was what a bunch of starving cavepeople had to do with anorexia. Anorexia was, like, about control and wanting to be thin like [insert cover model here]. It wasn't about evolution.

I have, of course, changed my thinking on that a bit. I don't think Guisinger's theory explains everything about anorexia, but it does provide an interesting perspective that is worth listening to. But my motive for posting this stems from an excerpt of her 2003 paper she quoted in a recent letter to the editor that really addresses the resistance many professionals have had in acknowledging the biological basis of anorexia:

Eating disorder specialists have overlooked the adaptive significance of these symptoms because current theories were developed when the pendulum in psychology and psychiatry had swung away from evolutionary explanations. For example, as late as the 1960s researchers had difficulty publishing findings showing that rats have innate abilities to learn to easily associate taste with subsequent nausea because reviewers assumed the rat mind, as well as the human mind, was essentially a tabula rasa at birth. . . . Twentieth century clinicians were not trained to look for evolutionary adaptive processes.

Furthermore, it has been difficult to see a connection between the behavior of starved animals and dieting girls because humans tend to explain behaviors and beliefs in psychological terms. Today’s anorectics often attribute their self-starvation to a desire to be thin, while medieval women with holy anorexia explained the same behaviors with reference to piety. Humans try to make sense of their behavior post hoc, even when it emanates from sub-cortical structures.


(Emphasis mine)

Which really makes me wonder: how much of what we think about anorexia comes from a culturally-evolving script? And can we understand anorexia without that script?

Thoughts?

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5 comments:

Cathy (UK) said...

Another great post Carrie :)
OK, so I am convinced that anorexia nervosa evolves from within a person - i.e. the susceptible person is born with a variety of inherent characteristics or temperament traits that significantly increase their vulnerability to developing anorexia nervosa or other anxiety/depressive-based illnesses. I also believe that the environmental triggers for a susceptible person's illness are interpersonal factors and factors such as social inclusion/exclusion, as well as the unique way that the susceptible person 'reads' and responds to the world around them.

Nowadays everyone has heard of anorexia nervosa, alongside the (unfounded but widely accepted) theory that it is caused by the media. When I developed anorexia nervosa in the mid 1970s hardly anyone had heard of the illness, including me and my family. I had no theories to explain my thoughts or behaviours because I hadn't been exposed to such theories. I described my illness as "a 'voice' in my head that tells me what I have to do". I didn't actually hear an audible voice; rather, I had powerful and intrusive thoughts about myself and my existence that seemed to come 'out of the blue'. The 'voice' instructed me to eat and exercise in a certain way and I felt compelled to obey that 'voice'. If I didn't obey it I became uncontrollably anxious.

We often read theories post hoc and think 'that applies to me', or 'that doesn't apply to me'. Had I grown up in the current technological climate with media images of thin women I might have supported the hypothesis that these images caused my anorexia nervosa - perhaps because, like many women say nowadays, they started to become sensitive to these images AFTER they had become anorexic. No person tried to explain my anorexia nervosa to me as a child, and I read no books about it. I just knew that it came from within me, during a period of extreme, existential despair.

Finding Melissa said...

I have also explored the cultural context and longer history of eating disorders in my recovery from chronic anorexia bulimia, so I am interested in these ideas. My focus has many been on the commonality of feelings over the centuries, as well as exploring the difficult relationship that women have had with food.
Making sense of a condition that seems so irrational is key to leaving it behind -

Harriet said...

Yes, yes, and yes. I think Guisinger's theory has a lot to recommend it. And I know from living with panic disorder for a long time all about our tendencies to rewrite our own narratives to make sense of them. It's what our brains like to do. Need to do.

Carrie Arnold said...

Cathy,

You're right- my fixation on unusually thin women didn't happen until after the starvation began to click in. My family is from good Eastern European stock- short (I'm the tallest female on either side of my family at 5 foot 5), and, while not large, not exactly waif-like either. Modeling was never going to be in my future, and I knew it and was okay with it.

I'm not sure if you've read Rudolph Bell's "Holy Anorexia," but it's an interesting read. I don't always agree with his central thesis and his insinuation that anorexia in the Middle Ages is fundamentally different from anorexia in the 20th-21st centuries. The context is different, but the illness is the same. Medival schizophrenics weren't going to be paranoid that the CIA was reading their minds because there wasn't a CIA. Those with OCD couldn't have a germ phobia because none existed. But that doesn't mean the disease is different, just how we interpret the symptoms.

Melissa,

Thanks for sharing your website- I'll admit I just logged on to my computer just now, so I haven't had a chance to look at it yet, but I look forward to it.

Harriet,

As a fellow writer, I have to agree that narrating our own experiences is sort of a human fundamental. People tell stories; it's what we do. And constructing your own story is a very powerful thing.

Unknown said...

I believe our stories and myths can be explanatory and helpful. Human cultures are always refining and redirecting our myths and stories, so when we perceive the narrative we were using is based on incorrect assumptions we change them. I think that is happening with EDs. we used to have narratives that were the best we could do with the information we had, and they often worked to some degree. We now have additional stories to choose from - and because they are closer to the biological facts of the matter may work even better.

I happen to be reasonably convinced of Shan's story, and quite heartened by the reports of people like my daughter who found the evolutionary biological angle both explanatory and therapeutic.

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I'm a science writer, a jewelry design artist, a bookworm, a complete geek, and mom to a wonderful kitty. I am also recovering from a decade-plus battle with anorexia nervosa. I believe that complete recovery is possible, and that the first step along that path is full nutrition.

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nour·ish: (v); to sustain with food or nutriment; supply with what is necessary for life, health, and growth; to cherish, foster, keep alive; to strengthen, build up, or promote



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