Biological Explanations for Anorexia Nervosa - Evolutionary

Question 1

What are the two hypotheses related to the evolutionary explanation of Anorexia Nervosa?

Answer 1

The Reproductive Suppression Hypothesis

The ‘Adapted to Flee’ Hypothesis

Question 2

The Reproductive Suppression Hypothesis
AO1
Key Study

Answer 2

Surbey 1987

Question 3

The Reproductive Suppression Hypothesis

AO1 (Detailed)

Answer 3

Surbey 1987 suggests that adolescent girls’ desire to control their weight represents an evolutionary adaptation in which ancetral girls delayed the onset of sexual maturation in response to cues about the probability of poor reproductive success

The ability to delay reproduction is adaptive because it enables a female to avoid giving birth at a time when conditions are not conducive to her offspring’s survival.

This model is based on the observation that in a number of species puberty is delayed or reproduction suppressed in females when they are subjected to stress or are in poor physical condition.

Surbey argues that Anorexia Nervosa is a ‘disordered variant’ of the adaptive ability of females to alter the timing of reproduction at a time when they feel unable to cope with the biological, emotional and social responsibilities of womanhood

Question 4

The Reproductive Suppression Hypothesis

AO1 (Summary)

Answer 4

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Question 5

The Reproductive Suppression Hypothesis
AO2
Supporting Evidence

Answer 5

This hypothesis is support by the observation that the onset of puberty is delayed in prepubertal girls with Anorexia Nervosa. Additionally, since amenorrhoea is a typical characteristic of Anorexia Nervosa, this means that reproduction is effectivey suspended in anorexic females

Question 6

The ‘Adapted to Flee’ Hypotheis
An Adaptive Response to Famine Conditions
AO1
Key Studies

Answer 6

Guisinger, 2003

Question 7

The ‘Adapted to Flee’ Hypotheis
An Adaptive Response to Famine Conditions
AO1

Answer 7

This hypothesis proposes that the typical Anorexia Nervosa symptoms of food restriction, hyperactivity and denial of stravation, reflect the operation of adaptive mechanisms that once caused migration in response to local famine conditions.

Normally, when a person begins to lose weight, physiological mechanisms conserve energy and increase desire for food.

However, among ancestral nomadic foragers, when extreme weight loss was due to a severe depletion of local food resources, the adaptation of an increased desire for food must be turned off so that individuals can increase their chances of survival by migrating to a more favourable environment without having to worry about food.

Question 8

The ‘Adapted to Flee’ Hypotheis
An Adaptive Response to Famine Conditions
AO1 (Summary)

Answer 8

g

Question 9

The ‘Adapted to Flee’ Hypotheis
Migratory Restlessness
AO1

Answer 9

The hyperactivity typically found in anorexics may be a form of ‘migratory restlessness’ as many species increase activity in times of food shortage and prior to migration. In the EEA those starving foragers who decieved themselves about their physical condition would have been more confident about moving on to a more favourable (in terms of food availability) environment, and so would have been more likely to survive. Therefore, for modern-day individuals, among those who are genetically vulnerable to Anorexia Nervosa, losing too much weight may trigger these ancestral mechanisms

Question 10

The ‘Adapted to Flee’ Hypothesis
Migratory Restlessness
AO1 (Summary)

Answer 10

g

Question 11

The ‘Adapted to Flee’ Hypothesis
AO2
Treatment Implication of the ‘Adapted to Flee’ Hypothesis
Key Studies

Answer 11

Guisinger, 2003

Question 12

The ‘Adapted to Flee’ Hypothesis
AO2
Treatment Implication of the ‘Adapted to Flee’ Hypothesis

Answer 12

Gusinger claims that the The ‘Adapted to Flee’ Hypothesis ‘relieves therapist of the need to search for familial reasons for Anorexia Nervosa’. This means that the therapist can relieve guilt from the familiy by emphasising the fact that according to this approach Anorexia Nervosa is biologically caused and that they understand that the individual has a great struggle

Question 13

AO2

Problems associated with evolutionary explanations

Answer 13

We might question how the symptoms of Anorexia Nervosa might be passed on by natural slection, particularly as they decrease fertility and could even kill the individual with this condition. Anorexia Nervosa would have functioned more effectively in ancestral conditions, yet outside the ecological setting in which it evolved disorders such as Anorexia Nervosa can be deadly.

Question 14

AO2

Gender Bias

Answer 14

Most studies of eating disorders have concentrated on the study of women but, according to recent statistics, 25% of adults with eating disorders are men. Whether that figure