Move Over WHR and BMI: Abdominal Depth Has Entered the Building
Using photographs and videos of actual women, like the one below, Rilling et.al. (2009) have found that abdominal depth (“the depth of the lower torso at the umbilicus”) and waist circumference are stronger predictors of attractiveness than either waist-hip-ratio or body-mass index. I can imagine the lead story in the science section of the local paper now: “Bodies that don’t look pregnant really are attractive.” As we all know, headlines can be misleading and popular presentations of research can gloss over subtle details. Pregnancy is not the only cause of abdominal swelling (there are actually 420 causes of abdominal swelling – none of which seem particularly desirable or healthy).
Abdominal depth measurement is illustrated below (the black line across the participant’s midsection)
while waist circumference is illustrated in the following image.
The stimulus set reveals strengths and weaknesses:
- Un-retouched photographs
- Three-dimensional views
- Blurred faces/heads
Generally, this stimulus set has excellent ecological validity.
- Stimuli skewed toward the unattractive end of a ten-point scale (mean of 4.9/10) – making it very hard to draw conclusions about what is actually attractive
- Leotards and raised arms will flatten breasts, making them appear smaller – possibly leading raters to over-rely on apparent waist thickness, especially in profile
- Relatively large mean waist circumferences in the stimuli – mean of 69.1 cm compared to 59.1 in Playboy centerfolds
- Stimulus set contains few figures with optimal waist-hip ratios – making it hard to assess the contribution of the preferred WHR.
In the end, this study does not get us much closer to resolving the WHR/BMI/???? debate. A quick inspection of measures that had statistically significant correlations with attractiveness ratings:
- Abdominal depth
- Chest circumference
- Chest/Underchest ratio
- Hip circumference
- Leg/Stature ratio
- Mid-arm circumference
- Pelvic width
- Underchest circumference
- Waist circumference
suggests the perhaps obvious conclusion that raters consider proportionality and size when evaluating the attractiveness of female bodies.
FYI: Table 1 has a nice summary of correlations between various bodily measures and health. This alone makes the article worthy of a look.
J RILLING, T KAUFMAN, E SMITH, R PATEL, C WORTHMAN (2009). Abdominal depth and waist circumference as influential determinants of human female attractiveness. Evolution and Human Behavior, 30 (1), 21-31 DOI: 10.1016/j.evolhumbehav.2008.08.007