Estradiol and progesterone are hormones related to fecundity and fertility in women. Fecundity refers to the probability of conception per act of intercourse and fertility refers to the probability of successfully completing pregnancy.

A recently published study assessed the relationship between estradiol levels, progesterone levels and facial masculinity-femininity in 59 young white women not on contraceptives (mean age = 20.4 years, S.D. = 1.5 years, range = 18-24 years). Estradiol and progesterone levels were assessed from their metabolites in urine samples provided by each of the women once per week for 4-6 weeks, and the women were photographed each time they visited the research lab. The women provided information about their menstrual cycle from diary data to enable the researchers to use hormone levels at the same stage of the menstrual cycle of the participants.

When photographed, 32 participants were not wearing make-up but 27 were.

The first photograph taken (week 1) was used for ratings if the participant had either always worn make-up (n = 27) or always not worn make-up (n = 14) in all the photographs. If there was a combination of no make-up and make-up photographs (n = 18), the first photograph with no make-up was used.

The faces were rated on masculinity-femininity, attractiveness and perceived health. Individual faces were rated by 15 women and 14 men of similar age to the participants. A composite face was formed using the faces of women with the ten highest estradiol levels at the most fecund phase of their menstrual cycle and another composite face was formed using the faces of women with the ten lowest estradiol levels at the most fecund phase of their menstrual cycle. The two composites were rated by 11 women and 10 men of similar age to the participants.

In the individual face ratings, for women without make-up, faces rated as more feminine, more attractive and healthier corresponded to higher estradiol levels for each of the three ratings and tended to correspond to higher progesterone levels for the attractiveness and perceived health ratings. These finds were not found for women wearing make-up. A possible interpretation of these finds is that make-up masks actual masculinity-femininity and attractiveness in women to some extent, which could be definitively concluded in this study if the make-up vs. non make-up comparison involved the same women, but this wasn’t the case. Nevertheless, any cosmetologist knows that make-up is used by women to mask their shortcomings and make themselves better looking. Additionally, the raters described faces with make-up as more feminine, more attractive and healthier, i.e., it is clear why some women use make-up. It should be noted that women wearing make-up when photographed did not differ in age, estradiol levels and progesterone levels from those not wearing make-up.

The two composite faces mentioned above are shown below; click on the image for a larger picture. The composite made from women with the highest estradiol levels (left) was rated as more feminine, more attractive and healthier than the composite made from women with the lowest estradiol levels (right). Indeed, the nature of face shape variation resulting from sex hormones is well-known and the left photo below is clearly seen as more feminine. Additionally, male and female raters similarly rated both the individual faces and the composite faces.

An evaluation of the composites was not done for progesterone levels because there was a strong positive correlation between estradiol and progesterone levels (r = 0.67, p < 0.001).

Ratings of femininity, attractiveness and perceived health were strongly correlated with each other and found to result from a single common underlying factor explaining 84% of the variance in these ratings; this factor was termed the quality factor. A higher quality rating corresponded to higher estradiol levels (r = 0.54, p = 0.002, n = 30) and tended to correspond to higher progesterone levels (r = 0.35, p = 0.058, n = 30). Given the positive correlation between estradiol and progesterone, further analysis revealed that estradiol but not progesterone was the independent predictor of the quality of physical appearance.

The results of this study should not be surprising. At the level of the population, there is bound to be some relation between fecundity/fertility and physical appearance, i.e., this is one of many examples showing that it is naïve to believe that the central tendencies of aesthetic preferences in a population are socially constructed.

References:

M. J. Law Smith, D. I. Perrett, B. C. Jones, R. E. Cornwell, F. R. Moore, D. R. Feinberg, L. G. Boothroyd, S. J. Durrani, M. R. Stirrat, S. Whiten, R. M. Pitman and S. G. Hillier. Facial appearance is a cue to oestrogen levels in women. Proc. R. Soc. B (2005), doi:10.1098/rspb.2005.3296.