Etiology of Bulimia
What are the factors which
contribute to people
developing bulimia?
Biological level of analysis
Strober (2000) found that
first-degree relatives of
bulimia sufferers are 10
times more likely than
average to develop
bulimia.
Biological level of analysis
 Kendler et al (1991) studied 2000 female twins
 Concordance rate of 23% for MZ and 9% for DZ
twins for eating disorders.
 What does this mean?
Biological level of analysis
Can you think of any
limitations of using selfreporting as a means
of gathering data on
eating disorders?
Biological level of analysis
 There is a link between eating disorders and the
genes responsible for the production of serotonin.
 There is low serotonin activity in many sufferers of
eating disorders.
 Which other disorder is also linked to low
serotonin activity?
Weight set point
 There is a theory that every individual has a
weight set point.
 What do you think this might be?
Weight set point
 There is a theory that every individual has a
weight set point.
 What do you think this might be?
 The weight level that a person is predisposed to
maintain, controlled in part by the hypothalamus.
 (Remember Hetherington & Ranson?)
Evaluation of the biological
LoA

Research does indicate a biological difference between people with ED and without.

The anti depressant drug treatment is shown as successful. (reduces the effect of
serotonin)
HOWEVER
*Can not distinguish cause from effect!!
*Very small samples are used in research.
*No one bio mechanism has been pinpointed for ED.
*Cant account for why eating disorders have increased vastly in the past 30 years.
*Not a 100% concordance rate in bulimia with twins.
Cognitive level of analysis
 The body-image distortion hypothesis
 (Bruch 1962)
Cognitive level of analysis
 Slade & Brodie (1994)
 Reformulated the body-image distortion
hypothesis
 Sufferers of eating disorders are in fact uncertain
about their size and shape
 And when compelled to make a judgement,
tend to overestimate their size
Fallon & Rozin (1985)
 American undergraduates asked
 Which figure is most like you
 Is most like your ideal shape
 Is most like the figure that the opposite sex find
attractive
Polivy & Herman (1985)
 Cognitive disinhibition
 Dichotomous thinking (all or nothing)
 Bulimics follow very strict dieting rules, when they
break them they tend to binge eat.
 Dieters and non-dieters took part in a ‘taste test’
 Given a milkshake before being asked to taste 3
types of ice-cream (told to eat as much as they
liked)
 Dieters ate more than non-dieters
Cognitive level of analysis
Evaluation
Describes rather than explains
Distorted eating patterns may
affect distorted thinking patterns
rather than the other way around
Sociocultural level of
analysis
 Do ideals of beauty change over history?
 In what way?
 How about between cultures?
Media’s Influence:
Internet Videos
 What types of messages about appearance are communicated
through magazines, advertisements, movies, and TV shows?
 http://www.dove.us/#/features/videos/videogaller
y.aspx/
Media
Other People
 What negative messages about our bodies do
we receive from parents, friends, coaches,
teachers and others?
 Childhood teasing, particularly by peers
 Loved ones disapprove or criticize
 Coaches make suggestions to improve performance
 Indirect comments by parents and friends
Cultural Expectations
 In some cultures a rounder figure is the ideal whereas in
others a slim build is considered beautiful.
 If our bodies do not match the cultural expectation of where
we live, we may strive to make our body look like the ideal.
This may lead to unhealthy eating and exercising practices.
Barbie ®
 Her waist is the same
diameter as her head.
 Her neck is twice as
long as an average
human’s.
 Her legs are 50%
longer than her arms.
(On average they
would be 20% longer.)
 She is 35 lbs
underweight.
 International Journal of
Eating Disorders, 1995
Ken ®
 Compared to an
average-sized male




Height is +51 cm
Waist is +25 cm
Chest is +28 cm
Neck is +20 cm
 (International Journal of Eating
Disorders, 1995)
 Action figures such as
Superman and Spiderman
are always depicted with
exaggerated muscles.
 Heroes on video games are
usually “big, strong, and
powerful”.
Body
dissatisfaction is
the strongest
predictor of risk
for developing
an eating
disorder!
Influence of the media
 How much influence does
the media have on our idea
of how we should look?
 How could research be
conducted to find out the
effects of the media on
body image?
Influence of the media
 How much influence does
the media have on our idea
of how we should look?
 How could research be
conducted to find out the
effects of the media on
body image?
 Now read pages 223-224 of
‘Levels of Analysis in
Psychology’
Course Companion
 Read (or reread) p162 – 165
of the Course Companion.
 Make detailed notes on the
three levels of analysis in
relation to the etiology of
bulimia.
 Do a detailed yellow study
sheet on Jaeger et al’s 2002
study.