Evolutionary Explanations, for one eating disorder: Anorexia Nervosa. Evolutionary explanations of anorexia nervosa: Pseudopathology (Crawford, 1998) · A pseudopathology is an illness brought about by an entirely intact adaptive mechanism responding in a modern environment it was not designed for. · In terms of evolution, women strive to be attractive to men. In the past this will have meant being able to provide and carry children; now it means being thin. · The result is that there is an adaptive advantage to being thin.
The adaptation mechanism is in place and is working, but under the socio-cultural pressures of the media of today the result may be anorexia. Adapted to Flee Famine Hypothesis (AFFH) (Guisinger, 2003) · Features of anorexia helped early humans to migrate to more plentiful environments in response to local famine. · Efficient migration meant switching off the usual adaptations to hunger (lethargy, energy conservation and hunger). · Therefore, restricting food intake, denial of starvation and hyperactivity could help migration.
Thilst no longer an adaptive response, a very low body weight (e. g. through dieting) may make the body respond as if threatened by famine, and result in anorexia. Controlled infertility (Wasser and Barach, 1983) · Whilst on the face of it an evolutionary disadvantage, stopping menstruation may actually be adaptive. · Women invest a lot in the relatively few children they can have in their lifetime, so that having one in a time of famine is very risky indeed.
Infertility brought about by controlled food intake might have allowed our ancestors to control when they produced children. · This protects the mother, frees up food for others that need it, and existing children would be more likely to survive to the next generation. Delayed reproduction (Sturbe, 1987) · Delaying reproduction to later in life allows a woman to seek and achieve security and provide better for a child. · E. g. , instead of becoming pregnant, teenager may go to university and afterwards get a better job.
This allows the woman to be more choosy and attract a better quality mate. Caring-for-kin hypothesis (Voland and Voland, 1989) · Anorexics are often very caring and protective of their own families. · Anorexics women often come from extremely protective (even over-protective) families. Being anorexics and therefore infertile produces an additional family helper, providing for advancement of the genetic line vicariously through other children in her family.
Evaluation of evolutionary explanations: Given the importance of survival and reproduction in evolutionary theory, eating disorders are puzzling conditions since both are threatened by these disorders. Evolutionary explanations are difficult to prove or disprove scientifically. It is not clear whether one evolutionary explanation is correct or whether they all are; and eating disorders could occur for a number of evolutionary reasons – this is a weakness of the approach.