Post on 17-Dec-2015
Visual Stimuli
• Two dimensional
• Line drawings
• Realistic? Representative? Valid?
Henss (2000)
• Facial attractiveness research
• Differences between line drawings and photographs
• Artifacts and/or validity re: WHR using line drawings?
Method
• Colour photographs, digitally manipulated by tightening or widening hips
• Original, smaller WHR, wider WHR• Between-subjects design (each subject only
saw one picture)• Standard type of rating questions (e.g.,
attractiveness, fecundity, youthfulness, etc.) and personality
Images
Range of WHRs
• Quite inconsistent
• Different poses of figures
Stimulus 1 2 3 4 5 6
Smaller 0.74 0.73 0.68 0.72 0.71 0.68
Original 0.77 0.76 0.70 0.79 0.76 0.72
Wider 0.82 0.81 0.71 0.85 0.80 0.74
Results
• Only attractiveness was significantly affected by manipulation of WHR
• Smaller WHR was most attractive, then original, and lastly wider
• Tightening hips makes woman appear taller– Lower 175.5cm, original 174.2cm, wider
173.6cm
• Smaller WHR, smaller BMI; related to height
Overall
• In general, confirms Singh’s WHR findings• Still, valid arguments against line drawings• Why use single individual as varied stimuli?
– Issue of generalization
• Different individuals were given different ratings on personality dimensions in this study
• Consistent with facial research, showing that personality judgments influence attractiveness ratings
Puhl & Boland (2001)
• Computer manipulated full figure photographs• Selected from a number of women to get two
models with WHR of 0.72 and 0.86, both in healthy BMI range
• Width of figures reduced and increased by 20%– Assumption that this would correspond to underweight
and overweight BMI conditions
• Between subjects design
Images
Results
• Underweight significantly more attractive• Model B more attractive than model A• Fecundity differences• Subjects distinguished weight levels• Females rated figures more attractive than males
Interpretation
• Strongly within the sociocultural perspective
• Model B has higher WHR (more “tubular”), therefore, must support media preference for thin (i.e., “tubular”) models
• However…
Swami et al. (2008)
• Not just WHR literature utilizing line drawings
• Vast majority of body image studies has traditionally relied on 2D line drawing representations
• Photographic Figure Rating Scale (PFRS)– 10 photographic images of real women varying
in BMI
• Is this a valid scale?
Images
Measures
• Rank figures from thinnest to heaviest
• Identify any figures that were emaciated or obese
• Body Appreciation Scale– 13 items measuring body image
• Demographic measures of subjects
Findings and Implications
• PFRS shows good construct validity
• BMIs from images can be successfully and consistently rank ordered
• Further testing of this type for future (and even current) image banks would be beneficial
• Can apply same approach to 3D images
Fan et al. (2004)
• Body scanned 31 Caucasian females
• 3D “wire frame” figures
• Blue figures on grey background
• Rotated 360°
• Hong Kong Chinese male and female raters– Mostly students in fashion and textile department
• Rate for attractiveness
Images
Results
Results
• Linear regression: BMI and WHR accounted for 75.8% of variance– BMI (72.7%), WHR (1.4%)
• Log regression: now BMI and WHR account for 82.1%– BMI (80.4%), WHR (1.7%)
Smith, Cornelissens & Tovee (2007)
• Evaluating assessment of health in mate choice• Colour video clips of 43 actual women showing
360° rotational views of their figures• Mean age = 20.7• BMIs from 18.4 to 26.7 (mean=22.4)• Percent body fat from 21.1-34.2% (mean=27.7%)• Cardiovascular fitness (VO2)• WHR (0.72-0.84, mean=0.74), WCR, torso-to-leg
ratio, leg length• Caucasians, but differences in skin tone
Example Image
Results
• No significance relationships between attractiveness and cardiovascular fitness or WHR
• Significant relationships between attractiveness and % body fat and skin tone index
Role of Characteristics
• With these stimuli, attractiveness judgments best explained by % body fat– WHR and WCR both co-vary with body weight
• Darker skin tone given higher attractiveness ratings– Social hierarchy of tanning? – Seems largely specific to Caucasians in
Western culture
Fitness• More realistic images than any earlier 3D
representations• Cardiovascular fitness is good predictor of long-
term health• Perhaps only assessed during physical activity
– Brown et al. (2005) dancing study
• Ancestrally, body fat may have been closely linked to cardiovascular health– In modern industrial society, body fat and
cardiovascular fitness can be decoupled– Makes fitness judgments more difficult
18 Years Later…
• Initial implications of universal preference for WHR=0.7 not supported
• However, with a few exceptions, findings support male preference for lower WHRs over higher WHRs
Shape and Weight
• A consistent, ongoing issue of confounds
• Difficult to successfully separate
• Camps of shape supporters and weight supporters
WHR as First Pass Filter?
• Probably not
• Weight (BMI, volumetric estimations, etc.) probably account for greater variability in attractiveness judgments
• Facial features
• Personality
• Complex interactive function
Effects of Weight Removed
• Does WHR make significant predictions of attractiveness with effects of weight removed
• Seems to be “yes”• Both empirical and theoretical support for
importance of WHR in judgments• Both shape and weight predictors of health
and fertility
Environmental Parameters
• Local resource hypothesis
• Recent work showing that adaptations may be more rapid than previously believed
• Evolved adaptations are generally predispositions, especially at the level of complex behaviour
• Intersection with learning
Limitations of Studies re: EEA
• University students (age, socioeconomics, enculturation)
• Culture (1st world, 3rd world, hunter-gatherer)
• Comparisons back to actual EEA• E.g., consider the ambiguities of the role of
clothing…
Progression in Science
• Started as a rather simple, but testable, EP hypothesis
• Good scientific theories are “fruitful”
• Nearly 20 years on
• A lot of research has been generated