Unintended consequences

Oral contraceptives suppress not only ovulation but also concurrent behavioral and attitudinal changes, including the desire to look more attractive. Has "the pill" changed our culture?

The oral contraceptive pill prevents pregnancy by suppressing ovulation—in short, by fooling a woman's body into thinking it is already pregnant. In addition to medical side effects, "the pill" also seems to modify behavior and attitude, often subtly. Whereas women are more likely to initiate sexual behavior at ovulation, this effect is suppressed in women on the pill (Adams et al. 1978). The latter also prefer men whose faces are less masculine (Little et al. 2002) and lighter-skinned (Frost 1994).

Among non-pill-users, ovulation coincides with greater use of cosmetics and increased time spent putting on cosmetics (Guéguen 2012). This behavioral effect seems to be likewise suppressed by pill use:

We photographed a sample of women (N = 36) who self-reported whether or not they use the contraceptive pill, as well as their cosmetic habits. A separate sample of participants (N = 143) rated how much makeup these target women appeared to be wearing. We found that women not using the contraceptive pill (i.e., naturally cycling women) reported spending more time applying cosmetics for an outing than did women who use the contraceptive pill. We also found that the faces of these naturally cycling women were rated as wearing more cosmetics than the faces of the women using the contraceptive pill. (Batres et al. 2018)

These findings are consistent with the results of a study on professional lap dancers. The participants made $335 in tips per 5 hour shift during ovulation, but only $260 per shift during the luteal phase and $185 per shift during menstruation. Lap dancers on contraceptive pills showed no change in earnings over the menstrual cycle (Miller et al. 2007). It's unclear what sort of visual or behavioral cues were suppressed by pill use:

[...] our study did not identify the precise proximal mechanisms that influence tip earnings. These might include the previously documented shifts in body scent, facial attractiveness, soft-tissue body symmetry, waist-to-hip ratio, and verbal creativity and fluency—or they might include shifts in other phenotypic cues that have not yet been studied. We can, however, exclude some possible mediators based on previous exotic dancer research. Tip earnings are unlikely to be influenced by cycle shifts in stage-dance moves, clothing, or initial conversational content because these cues just do not vary much for professional dancers (Miller et al. 2007)

Do women naturally have a more attractive physical appearance at ovulation?

Discussion

The past half-century has seen a trend toward androgyny among women. This trend is usually attributed to feminism and pop culture, but perhaps the latter have in turn been influenced by something else.

Today, "the pill" is used by approximately 100 million women worldwide, particularly in developed countries. Has this widespread use played a role in changing our cultural and ideological environment? 

I'm not suggesting that women look less feminine today simply because more of them are on the pill and thus are hormonally altered. Rather, if a larger proportion of women are in that kind of hormonal state, it will be easier for anti-feminine fashions and ideologies to achieve a critical mass and take off among all women, including those not on the pill.

References

Adams, D.B., A.R. Gold, and A.D. Burt. (1978). Rise in female-initiated sexual activity at ovulation and its suppression by oral contraceptives. New England Journal of Medicine 299: 1145-1150.

https://doi.org/10.1056/NEJM197811232992101  

Batres, C., A. Porcheron, G. Kaminski, S. Courrèges, F. Morizot, and R. Russell. (2018). Evidence that the hormonal contraceptive pill is associated with cosmetic habits? Frontiers in Psychology 9: 1459

https://doi.org/10.3389/fpsyg.2018.01459

Frost, P. (1994b). Preference for darker faces in photographs at different phases of the menstrual cycle: Preliminary assessment of evidence for a hormonal relationship. Perceptual and Motor Skills 79(1): 507-14.

https://doi.org/10.2466/pms.1994.79.1.507.

Guéguen, N. (2012). Makeup and menstrual cycle: near ovulation, women use more cosmetics. The Psychological Record 62: 541-548. 

https://doi.org/10.1007/BF03395819

Little, A.C., B.C. Jones, I.S. Penton-Voak, D.M. Burt, and D.I. Perrett. (2002). Partnership status and the temporal context of relationships influence human female preferences for sexual dimorphism in male face shape. Proceedings of the Royal Society B. 269: 1095-1100. 

https://doi.org/10.1098/rspb.2002.1984

Miller, G., J.M. Tybur, and B.D. Jordan. (2007). Ovulatory cycle effects on tip earnings by lap dancers: economic evidence for human estrus? Evolution and Human Behavior 28: 375-381. https://doi.org/10.1016/j.evolhumbehav.2007.06.002