Mathematical analyses of classical proportions

Hips do lie

We do seem to find slim figures appealing – though ratios seem to be more important (and it depends whether we are hungry or not)

In less politically correct times, women were often described in terms of their ‘vital statistics’ – chest, waist and hip measurements in inches.

Ironically, the strongest candidate for a ‘beauty factor’ in women is an echo of those vital statistics. Many studies have found that a waist-to-hip ratio of around 0.7 is judged most attractive. This is independent of overall size: the actress Jessica Alba has a near perfect ratio, as did Marilyn Monroe, who was a couple of inches shorter.

First suggested in the 1990s, the waist-to-hip ratio theory has been interpreted in an evolutionary context. Women with this shape tend to be healthier and more fertile, so could be seen as better mates.

Sex discrimination

Overall, women tend to be less swayed by men’s physical appearance, though body mass index, waist-to-hip and, in particular, waist-to-chest ratios influence perceived male attractiveness. A study of choices in speed dating found that women were more discriminating than men (who tended to select partners simply on physical appearance), picking partners based on their overall desirability as a mate. This is also consistent with an evolutionary explanation.

Nonetheless, social and cultural factors will influence these preferences. For example, it appears that low socioeconomic status and even hunger increase the perceived attractiveness of larger people. This may be why some non-Western cultures are more likely to see larger sizes as attractive.

Lead image:

Mathematical analyses can help identify features associated with beauty. The proportions of the classical sculpture of Doryphoros by Polykleitos (centre) match a well-known ratio. When this ratio is altered, extending the abdomen (left) or the legs (right), the resulting physique is generally rated as ugly. Interestingly, objective analysis of body form and subjective assessments of beauty seem to involve distinct areas of the brain.

From Di Dio C et al. PLoS ONE 2007;2(11):e1201


About this resource

This resource was first published in ‘How We Look’ in June 2008 and reviewed and updated in November 2014.

Statistics and maths, Physiology
How We Look
Education levels:
16–19, Continuing professional development