WHR and Self Body Image
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Significant issues with body image
Body shape role in mate choice
Both sexes awareness of WHR issues
Is WHR specifically involved in self body
judgments?
Joiner, Schmidt & Singh (1994)
• Depression
• Limited earlier work on WHR and body
dissatisfaction
• Body dissatisfaction had been connected to
depression, bulimia, eating disorder
Subjects
• Undergraduates
• Questionnaires
– Beck Depression Inventory (BDI)
• BMI, WHR, anthropometric indicies
Findings: Just WHR
• Low WHR corresponds to higher body
dissatisfaction
• Agreement with Radke-Sharpe et al. (1990)
– Large hips and buttocks --> higher body
dissatisfaction
Findings: Interaction
• WHR x BDI x Gender interaction
• Body dissatisfaction more complicated
Cognitive Theories of Depression
• Depressive distortion
– Misrepresent own self shape
• Depressive realism
– Better/more accurate representation of self
shape
Sexual Dimorphism
Identification
• Results fit better with depressive realism
• Depressed people better at perceiving the
reality of what their WHRs convey
• Depressed males will be dissatisfied with
low WHRs (more gynoid)
• Depressed females will be more dissatisfied
with high WHRs (more android)
WHR as Adaptation
• Additional evidence for WHR playing role
in mate choice for some time
• Involvement with other psychological
constructs
Focused Attention
• Individuals can identify desired sexually
selected characteristics in others and self
• Predict that you would draw attention to
traits if beneficial
Singh & Bronstad (1997)
• Body scarification
• Standard Cross-Cultural Sample (SCCS)
– 186 societies
– Assess pathogen prevalence, polygyny, degree
and location of body scarification in population
– Can’t be used to determine individual specifics
Sex. Selection & Parasites
• Positive correlations between amount of
societal scarification and pathogen
prevalence
• Females more likely to scarify their
stomachs and breasts at higher pathogen
levels
If You’ve Got It, Flaunt It…
• High pathogen levels --> overall reduction
in potential mates
• Much more important to select
genotypically fit, healthy mates
• Scarification of sexually dimorphic
secondary sexual traits draws attention to
them
• Highlights fitness
www.ezakwantu.com/Scarifacation%20Abdoman%2002.jpg
www.ezakwantu.com/Scarifacation%20Abdoman%2011.jpg
www.ezakwantu.com/Scarification%20Face%2006.jpg
Navel Gazing
• Female scarification of stomach fits with WHR
interpretation
• Navel is indicator of natural waistline
• Woman who draws attention to desired WHR may
gain attention of higher quality males
• Other non-scarification ornamentation used to
similar purpose
– Corsets, belts, shawls, etc.
Henss (1995)
• Replicated and expanded Singh’s studies
• Methodology changes
• Between subjects design
– Avoid demand characteristics
– Each subject only saw and evaluated one figure
• Big Five personality factors
– Extraversion, agreeableness, conscientiousness,
emotional stability, intellect
• In all, 51 criteria subjects are assessing on
• 72 males, 72 females, Germany
Agreement with Singh
• Effects of body weight are considerably
stronger than those of body shape
• Underweight and normal rated more
attractive
• Overweight least attractive, but most
emotionally stable, family oriented,
agreeable, and conscientious
Differences from Singh
• WHR 0.8 most attractive (then 0.7)
• Underweight more attractive than normal
weight
Attractiveness
• Singh: “attractive” and “sexy”
• Henss: weighted composite of 51 scales
– Ran collapsed analysis of 15 scales
– Still U>N>O, whereas Singh had N>U>O, but
closer
• May also be a difference in the within- vs.
between-subject design
Overall
• General agreement with Singh’s findings
• Some quibbling over particulars
• Body weight and body shape being used in
attractiveness judgments
Furnham, Tan & McManus (1997)
• Singh’s ranked data strictly non-parametric;
parametric data more powerful
• Used ratings (7 pt. Likert scale) instead of
ranking
• Participants judged all figures; withinsubject
• British subjects
Broad Results
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Attractiveness: N>U>O
Healthiness: N>O>U
Youthfulness: U>N>O
Overall, WHRs of 0.7 or 0.8 rated most
favourably for all factors, regardless of
weight
Compare and Contrast
• Unlike Henss (1995), but like Singh, none of the
underweight figures considered most attractive
• Normal weight figures rated highest for everything
but youthfulness
• Across weights, high WHRs rated unattractive,
unhealthy, and unyouthful
• Like Henss, WHR of 0.8 rated most attractive
Contribution
• Generally agrees with Singh
• Along with Henss, identifying body weight
as more significant than body shape in
judgments
• Still arguing for WHR as adaptive trait in
mate choice
• Is it first-pass filter, though?
Universiality?
• By 1997 still general support for WHR
• American (Caucasian, Mexican, Black),
Indonesian, German, British subjects
sampled
• But what about non-industrialized?
Yu & Shepard (1998)
• Yomybato: Matsigenka indigenous people in
Manu Park, Peru
– Slash and burn agriculture, hunting and gathering
– About 300 people in population
– Extremely non-Westernized
• Shipetiari: Matsigenka people living outside Manu
Park
– More exposed to Western culture
• Alto Madre: ethnically mixed population of
Amarakaeri, Huachipaeri, and Piro
– Even more Westernized
Method
• Singh’s figures
• Used U7, N7, O7 and U9, N9, O9 figures
• Males asked to rank figures from most to
least for beauty, health, and marriage
preference
Results
• Yomybato and Shipetiari
– Grouped figures by weight first, then WHR
– Preferred overweight figures
– High WHR more healthy
• Shipetiari
– Low WHR figures more attractive and desirable as
spouses
– Didn’t consider healthiest to be most attractive or
desirable
– “…suggesting that WHR preferences may be
changing.” (321)
• Alto Madre
– Didn’t differ significantly from American
judgments
– Grouped figures by WHR first, then weight
– N7 generally ranked highest
– Low WHR figures always ranked higher than
high WHR figures
Nurturist Account
• Argue that Singh’s results are due to
Western media
• Least Westernized of tribal peoples showed
most difference from American population
• “…many ‘cross-cultural’ tests in
evolutionary psychology may have only
reflected the pervasiveness of western
media.” (322)
• But, no explanation of why Western media
would favour low WHRs
In Small Populations
• With small population sizes, limited mate
choices
– Few people, kinship, etc.
• Individuals would have detailed knowledge
of health history of potential mates from
long-term personal contact
• Physical features may take on secondary
role in mate choice
Wetsman & Marlowe (1999)
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Hadza of Tanzania
Mixed savanna, woodland environment
Small population of only 1000 individuals
1/3 exclusively hunter/gatherer
– Only used males form this group for the study
• Hunger not uncommon, but no one can
remember anyone ever starving
• No one obese
Method
• U7, N7, O7 and U9, N9, O9
• Forced choice for attractiveness, health,
preference for wife
• 75 men (18-68 years, mean 37)
• Also, American undergrads (24 subjects,
mean age 21.2)
Results
• American undergrads
– Same pattern as Singh’s earlier studies
• Hadza
– No significant preference based on WHRs
– Used body weight
– Strong preference for overweight, then normal,
than underweight for all criteria
Environment Input
• Suggests WHR a second-pass filter, not
first-pass
• Propose differing environmental input
model
• Food scarcity determines hierarchy of
selection
In Food Scarce Environments
• Best option is to use body weight
• Survival first, reproduction second
• If WHR used first, most attractive,
healthiest females may starve before
reproducing or never achieve enough fat to
be able to reproduce
• Even if higher weight conferred some
health detriments, higher fat stores preferred
– None of Hadza are obese
In Food Rich Environments
• Risk of starvation low
• WHR better predictor
• Here too much weight can compromise
reproductive fitness
Marlowe & Wetsman (2001)
• Hadza (and American)
males
• Asked about:
attractiveness, health,
desirability for wife
• New set of figures
• Did not vary in weight
• Broader range of
WHRs
Results
• Americans disliked WHR of 0.9 and 1.0 and
also 0.4 and 0.5; general preference for
WHRs around 0.7
• Hadza preferred higher WHRs (0.8, 0.9, 1.0
all ranked above 0.7)
Concordances
• Measure of agreement among subjects
• Americans: greater concordances for
attractiveness and desirability to marry
• Hadza: greater concordance for health
• For Hadza health determines desirability for
marriage; for Americans it is attractiveness
Confound
• Even with no weight variation, Hadza still
preferring high WHR
• Artifact of preference for heavier women
• BMI confounded with WHR in Singh’s
original figures and with current figures
– Height is kept constant; as WHR increases from
0.4 to 1.0, so would weight in a real woman
– Females with larger waists look heavier
Theorizing
• Environmental differences
• Current fertility status
• Different female body shapes
Environment
• Among foragers, thinness probably indicates
poorer health (parasites)
• Women who are too thin are energetically stressed
• Will interfere with reproduction
• High energy demands on Hadza women
• Prior to agriculture health-threatening obesity
probably very rare
• Should have been preference for women with
more fat stores
Developed Nations
• Propose agriculture led to more predictable
and surplus food supply (at least for some)
• Risk of obesity increased
• Men developed preference for low BMIs
(and WHRs)
Fertility Status
• Pregnant women have high WHR
• Total fertility (TFR): average number of
children produced by a woman in a society
• American TFR = 2.1; Hadza TFR = 6.2
• High WHR (pregnant?)
– American: bad mate choice (probably only one
more child with her)
– Hadza: not so bad (up to another 5.2 children)
• The lower the TFR the more men favoured
for attending to signs of non-pregnancy
Different Female Body Shapes
• Different populations of humans
• Geographical isolation; different phenotypic
expressions; fat stores
• Health risks of 2D WHR presumed to
correlate with “real WHR” measure in 3D
• But, two women can have same frontal
WHRs, but different actual WHRs
Marlowe, Apicella & Reed (2005)
• Actual WHR = measurement with tape
measure
• Frontal WHR = 2D front view
• Profile WHR = 2D profile (side) view
• Frontal WHR doesn’t reflect buttock size
and profile WHR doesn’t reflect hips
• Actual WHR reflects both hips and buttocks
An Assumption
• If relative contributions of hips and buttocks
to actual WHR didn’t vary in women crossculturally, then frontal WHR would suffice
• Does it?
• Er… probably not
• Need a new stimulus set to test
• Use Hadza and Americans again; attractive,
healthy, wife
Theoretical Preference
• For actual WHR
• Based on study preferences
• Weighted the profile WHR 0.7 times that of
frontal WHR
• Theoretically preferred actual WHR =
[(preferred frontal x1.0) + (preferred profile
x 0.7)] / 1.7
Results
• Statistically analyzed men’s first choice
preference of five figures for three criteria
• Hadza profile WHR selection significantly
lower than Americans for all three criteria
• Prefer more protruding buttocks than
Americans
Outcomes
• Americans: preferred frontal WHR = 0.7
and profile WHR = 0.65
• Hadza: preferred frontal WHR = 0.9 and
profile WHR = 0.6
• Use equation for theoretically preferred
actual WHRs
• Americans: 0.68
• Hadza: 0.78
Actual Hadza WHR
Measurements
• Mean actual WHR
– Aged 17-82 = 0.83
– Aged 17-24 = 0.79
• Bit higher than other
populations, but not
the highest
• Non-agriculturalists
typically have higher
female WHRs
New Figures, Fuller Analysis
• Hadza and American men’s preferences for
women’s actual WHRs not as different as
previous two studies suggest
• Problem with just using frontal WHR
Comparison
• Hazda women do have higher WHRs than
American women
• Hadza, 17-24 years, WHR = 0.79
• American, 18-23, WHR = 0.73
• Why the difference? Some possibilities.
Parity
• WHR does rise with parity (number
children born)
• Hazda TFR=6.2, average age of first child =
19
• American TFR=2.1, average of first child =
25
Diet
• Bulky, fibrous tubers significant in Hadza
diet
• Require larger gut
• Humans aren’t ungulates…
Physical Activity
• Foragers more energetically active
• May favour higher androgen levels,
depositing more fat in abdomen
• Raises WHR
Environmental Selection
• High level foragers must be more efficient at
locomotion
• Pelvis suited for locomotion not optimized for
childbirth
• Evolutionary trade-off depending on environment
• Less for women to forage in colder climates
– Further from the equator, the less women need to be
optimized for locomotion
– Nearer equator, women contribute more resources to
diet
• Possible male preferences map on to variation in
females’ shape
Age-Based Selection
• WHR reaches trough shortly after menarche
• Male preference for WHR may be age-based
preference for nubility
• Maximization of RV
• Actual WHR could vary across populations with
variation in population mean postmenarcheal WHR
• Hadza males’ preference of 0.78 very close to young
females’ WHR of 0.79
• American males’ preference of 0.68 close to WHR of
young university aged women’s WHR (0.72-0.73)