The document discusses several biological, psychological, and evolutionary explanations for anorexia nervosa, including neural mechanisms like hypothalamus dysfunction, genetic factors, behavioral theories involving conditioning and social learning, psychodynamic views of using food restriction as a way to gain control or avoid adulthood, and evolutionary perspectives like the adaptive famine hypothesis. Debates remain around determinism versus free will and nature versus nurture in understanding the complex causes of this eating disorder.

1. Anorexia Nervosa
Biological Explanations
1. Neural
2. Evolutionary

2. - This means cessation -Excessive fear of
of menstrual periods. Fear of becoming fat. People
The absence of three with anorexia are not
consecutive periods in
weight gain simply obsessed with
women who are of weight but fearful of
menstruating age weight gain
Amenorrhoea
Anorexia Abnormal
Nervosa Weight
-People with anorexia do
not see their own thinness. -Weight loss is
They often continue to see considered abnormal
themselves as fat despite when it drops below
the fact that their bones Body image
85% of the individuals
can be clearly seen. They distortion normal weight based on
also often deny the
seriousness of their low age and height
body weight.

3. A01
Neural causes - HDT
RECAP: Lateral
Hypothalamus
What are the neural
and the
mechanisms involved in hunger
Ventromedial
and satiety?
Hypothalamus
Neural cause - Hypothalamus
Lateral Hypothalamus
Dysfunction Theory (HDT)
– functions as the
hunger centre
When weight is low, the
LH is activated.
Ventromedial
When weight is high, Hypothalamus –
the VMH is activated.
operates at the
satiety centre

4. A01
Neural causes - HDT
Humans and other animals have a „set weight‟ (homeostasis) that
is correct for them, anyone who falls below this weight will feel
hungry, and anyone who goes above it will eat less in order to
regain „normal‟ weight
Garfinkel & Gardner (1982) The hypothalamus is a
Disturbed Hypothalamic function weight thermostat
means that it doesn‟t keep weight
at a „normal level‟
The VMH or LH might be
constantly activated.
Link to AN:
The LH is damanged, causing the VMH to be over activated in
response – body always belives it is overweight, resulting in
restricted eating

5. Neural causes - HDT
Lashley (1938) found that lesions to certain parts of
the hypothalamus in rats causes changes in appetite and
hunger – leading to starvation or excessive binging
(depending on which part is damaged).
This offers empirical support for the role of the brain
in AN
A02
Also think back to: Hetherington & Ranson and Anand &
Brobeck

6. Neural causes - HDT A02
Approaches: Can AN be Debates: Cause and
better explained by the Effect
behavioural approach?
Is the hypothalamus
- Rise in media exposure, thin dysfunction the cause or the
role models, modelling result (effect) of AN?
programmes?
Ethics: Non-human
animals in research
The animals used when
testing HDT will have
Issues: Ratomorphism suffered after the
experiment due to the
lesions made…
Lots of evidence from non-
human animal studies but
humans don‟t necessarily Also, don’t forget..AO3.. How science works:
work in the same way - Extrapolation
-Laboratory experiments
-Scientific measurements

7. Neural causes - Serotonin A01
Think back: A neurotransmitter,
What is serotonin? associated with
What disorders is serotonin depression and
associated with? aggressive behaviour
Bailer et al (2007) compared serotonin activity in women
recovering from restrictive type anorexia (restricted food
intake) and binge-eating/purging type (periods of restrictive
eating and binge/purge behaviour) with healthy controls. They
found significantly higher serotonin activity in the women
recovering from anorexia. In addition, they found the highest
levels of serotonin in those with the most anxiety.

8. Neural causes - Serotonin A02
Most research into the
link between serotonin
and AN are conducted
on p‟s with an ongoing
eating disorder – why
might this be a
problem?

9. Neural causes - Serotonin A01
In PET scans, a drug is injected that binds with serotonin
receptors and when the brain scan is taken the drug shows up
as brightly lit areas. These areas can then be measured and it
gives an estimate of the number of serotonin receptors in
different areas of the brain.
Frank et al (2002) and Kaye et al (2005) conducted PET
scans and have shown that there are fewer serotonin receptors
in the brains of people with eating disorders.
More importantly Kaye et al (2005) found that these changes
are also found in people who have recovered from eating
disorders – how can this be used to support a link between
serotonin and eating disorders?
A02

10. Neural causes - Serotonin A02
Approaches: Can AN be Debates: Reductionist
better explained by the
behavioural approach? AN is caused by an issues with
serotonin levels may just be a
- Rise in media exposure, thin little to simple
role models, modelling
programmes?
Issues: Nomothetic
Theory suggests that the
causes of AN would be the
same for each individual
Debates: Deterministic however there are wide
individual differences
between this with AN
It ignores the role of free
will in eating behaviour
Also, don’t forget..AO3.. How science works:
-Laboratory experiments
-Scientific measurements

11. Evolutionary Explanations
- AFFH A01
What does the Evolutionary Theory suggest about human behaviour?
Good for
Adaptive
Survival
Guisinger (2003)
suggested that AN is a
reflection of eating
The EEA refers to the
behaviour that was
environment in which a
adaptive in the
species first evolved.
environment of
evolutionary adaptation
(EEA)

12. Evolutionary Explanations
- AFFH A01
When a person begins losing weight, physiological mechanisms
kick in and conserve energy and increase the desire for food.
However, in the EEA, extreme weight loss was due to severe
depletion of local resources - this adaptation must be turned
off so that individuals can increase their chances of survival
by migrating to more favourable (and more plentiful)
environments.
Therefore, the „switch‟ that increases desire for food and
energy conservation must be switched off so that migration
can occur.
If it is not switched off the individual will use resources
foraging for food rather than planning a migration
furthermore, the energy which is being conserved will be
needed for the move.

13. Evolutionary Explanations
- AFFH A01
Therefore the anorexic is able to „switch off‟ the desire for
food signals explaining how they are able to lose so much weight.
The hyperactivity found in anorexics may be a form of
“migratory restlessness” as many species increase activity in
times of food shortage and prior to migration.

14. Evolutionary Explanations A01
- Reproductive Suppression
Argues that adolescent girls‟ desire to control
their weight represents an evolutionary
Surbey
adaptation in which ancestral girls delayed the
(1987)
onset of sexual maturation in response to cues
about the probability of poor reproductive
success
This is adaptive because it
enables the female to avoid Don‟t forget what
giving birth at a time when the Evolutionary
conditions are not conducive approach says
to her offspring‟s survival about reproduction

15. Evolutionary Explanations
- Reproductive Suppression
This model is based on Surbey argues that the
the observation that in a anorexia is a “disordered
number of species, variant” of the adaptive
puberty is delayed or ability of females to alter
suppressed in females the timings of
when they are subjected reproduction at a time
to stress or are in poor when they feel unable to
physical condition cope with womanhood
Don‟t forget what
This hypothesis is supported by the observation that
the Evolutionary
menarche (the onset of puberty) is delayed in prepubescent
approach says
girls with AN and that amenorrhoea is a typical characteristic
about reproduction
of the disorder. This is because sexual maturity is suspended
in these women until the environment is more suited to raising
children successfully.
A02

16. Evolutionary Explanations
This hypothesis is able to explain some A02
characteristics of AN effectively, i.e. their constant
refusal to acknowledge their own hunger signals
Able to explain the genetic component in AN.
Holland et al (1988) supports the idea that Anorexic
behaviour patterns enabled Anorexia suffers to survive
to reproduce and pass on such behaviours genetically.
56% for MZ, 7% for DZ
However, this theory is unable to explain why girls are more
However, the Reproductive Suppression theory does do a
affected by AN than boys. Presumably, both genders would
little in the way of making a suggestion as to the gender
be equally likely to benefit from the ability to ignore
difference in AN sufferers, but the evolutionary theory
hunger signals until they had moved on to more plentiful
doesn‟t explain why there are male AN sufferers at all
land.

17. Evolutionary Explanations A02
Approaches: Can AN be Debates: Nature/Nurture
better explained by an
alternative approach?
- Rise in media exposure, thin
role models, modelling
programmes?
Issues: Unfalsifiable
It is impossible to test the
theory scientifically
Issues: Lack of
Issues: Lack of Evidence
Evidence We have no direct evidence for
this model
It ignores the role of free
will in eating behaviour
Also, don’t forget..AO3.. How science works:
-Difficulty testing

18. Anorexia Nervosa
Psychological Explanations
1. Behavioural
2. Psychodynamic

19. - This means cessation -Excessive fear of
of menstrual periods. Fear of becoming fat. People
The absence of three with anorexia are not
consecutive periods in
weight gain simply obsessed with
women who are of weight but fearful of
menstruating age weight gain
Amenorrhoea
Anorexia Abnormal
Nervosa Weight
-People with anorexia do
not see their own thinness. -Weight loss is
They often continue to see considered abnormal
themselves as fat despite when it drops below
the fact that their bones Body image
85% of the individuals
can be clearly seen. They distortion normal weight based on
also often deny the
seriousness of their low age and height
body weight.

20. Behavioural causes A01
- Conditioning
Learning
RECAP: through
What is operant conditioning? association
(positive and
negative)
Anorexic behaviour is
reinforced in some way
Compliments/attention
Concern for losing for losing weight
considerable weight becomes This makes the
positive reinforcement and individual more likely
again this makes the individual to repeat the
more likely to repeat the starvation behaviour
starvation behaviour

21. Behavioural causes A01
- Conditioning
Starts to alter
eating
behaviour
(e.g. Dieting)
Person feels
good about
themselves – in
control of Loses weight
eating
Reinforcement
of behaviour
(+ve & -ve)

22. Behavioural causes A01
- Social Learning Theory
RECAP:
Vicarious
What is the Social Learning learning
Theory? (through another
person)
Anorexia is learnt by observing
others
Role Model
Observation
Observation

23. Behavioural causes A01
- Social Learning Theory
Modelling – the behaviour and characteristics of
role models are imitated
If a famous person is seen as someone we wish to
be like, we are likely to want to be very thin like
they are
We observe them receiving positive
reinforcement for being thin, e.g. Fame, wealth
and attention
Makes the individual more likely to repeat the
behaviour

24. Behavioural causes A01
- Social Learning Theory
...because these
This theory suggests cultures will be
that AN will be more more likely to
likely to occur in have thin role
cultures that judge models –
self-worth in terms of reinforcing the
weight and shape weight loss
Media portrayals of thin
role models are also
suggested to have
Imagine a country where
the phrase “You‟ve contributed to
gained weight” is
considered a compliment development of eating
disorders

25. Behavioural causes A02
Approaches: Behavioural Issues: Deterministic
approach ignores cognitive
factors Suggests that anyone who have observed
another being reinforced or who have
- Behavioural approach been reinforcement themselves for
underplays the cognitive weight loss will develop an eating
aspects of AN, doesn‟t deal disorder
with the faulty perceptions of
body image that are typically
central to the disorder Issues: Reductionist
Reduces the complex nature
of eating disorders to simple
learning or response to a
Issues: Cultural Bias compliment.
Research conducted in Fiji
and views eating behaviour
from a Western Also, don’t forget..AO3.. How science works:
perspective - Sample
-Natural experiments

26. Psychodynamic
Explanations A01
Think back:
What are the main aspects of the Unconscious
psychodynamic approach? processes
1. Control
2. Fear of growing up
3. Family systems approach

27. Psychodynamic –
Control A01
Bruch (1973) suggested that AN was an attempt by the
individual to exert some control
Individuals with AN at some point struggled for autonomy and
the need to be independent from parents
This theory suggests that sufferers of AN discovered their
eating behaviour was one area of their life that they could
control – increasing autonomy and self-efficacy
Think back to Maslow and the hierarchy of need – does
this contradict the DIMH theory? A02

28. Psychodynamic –
Control
Romans et al (2001) –
Found evidence for a link
between childhood sexual
abuse and the
development of an eating
disorder. They found that
early maturation and
parental over-control
were risk factors for AN
A02

29. Psychodynamic –
Fear of Growing Up A01
Crisp (1980) developed theories as tot he cause of AN based
on the fact that self-starvation and loss of body weight led to
the postponement of menarche or the loss of menstruation
(amenorrhoea)
Crisp suggested that this was an unconscious attempt by the
girl to remain pre-pubescent, postponing the onset of adulthood
and therefore remaining in need of parental care
AN allows its sufferers to look child-like (amenorrhoea, breasts
stop developing) maintaining the illusion that they are still a
child.
Freud went on to extend the theory suggesting that eating was a
substitute for sexual activity – not eating is a way to repress sexual
thoughts, starving to remain pre-pubescent and sexually immature

30. Psychodynamic –
Fear of Growing Up
Romans et al (2001) –
Found evidence for a link
between childhood sexual
abuse and the
development of an eating A02
disorder. They found that
early maturation and
parental over-control
were risk factors for AN

31. Psychodynamic –
Family Systems Approach A01
Minuchin, Rosman & Baker (1978) attempt to explain AN by
using a family focussed approach
This theory suggests that a child develops AN as an attempt to divert
attention away from other family problems – in a misguided attempt to
keep the family together
For example – in cases
where the parents were Removing the parents
having relationship from their own issues with
problems, the AN sufferer each other – the ultimate
hopes that their illness will aim is to postpone a
create a common goal for separation.
the parents

32. Psychodynamic explanations
Approaches: Can AN be
better explained by an
Debates: Free will
A02
alternative approach? The Psychodynamic
explanations ignore the role
-Behavioural (learning) that free will can take in AN
-Biological (genetics)
Issues: Lack of
evidence
Lack of objective evidence,
the unconscious cannot be
Issues: Unfalsifiable observed, measured or
tested.
Cannot be proven to be
true or false
Also, don’t forget..AO3.. How science works:
-Lack of scientific measurements