Do Oral Contraceptives Affect Your Taste in Men?
Ladies! Did you know that your hormones make you do crazy things? And you're, like, totally controlled by them, even when you're not PMSing? So says science. Oh, wait, no, so says the trendy pseudoscience known as evolutionary psychology a.k.a. evo psych a.k.a. possibly the thing I hate most in the world next to gutter punks and cockroaches. You have probably heard before about research that shows that women, when asked by a researcher in a lab setting where all decisions are hypothetical, express preferences for different traits in their mates depending on where they are in their menstrual cycles. The leading theory, from what I understand, is that women tend to prefer mates with dissimilar genetics (specifically, with respect to the immune system) and masculine features when at their most fertile and care more about personality (and wealth and social status) when at their least fertile. The implication being that women experience competing evolutionary pressures - to find a genetically fit mate and at the same time to find a stable one who is likely to invest in childrearing. Which is a fair point. Evolution does this - it often provides alternate pathways to produce maximum adaptability. But evolutionary pressures are not destiny. Our biology is one of many factors in how people make decisions, mixed in with things like social norms and personality. That last bit is the one the evo psych types like to ignore, as if we all exist in a cultural vacuum and will do whatever the goddamn hormones tell us to (and as if those evolutionary pressures are in fact The Right and Natural Way to Do Things and also Something We Should Not Fuck With).
The latest study making the rounds is one that looks at the correlation between oral contraceptive use and relationship quality and length, and as you might have guessed, I'm not impressed. The central assumption of the study is that because oral contraceptives alter women's hormones, their use would have a significant impact on the men women choose to be in a relationship with. The study looked at the relationship satisfaction and outcomes of 2519 women from the US (1220), the Czech Republic (999), UK (159), Canada (98), and other countries (43). The women were surveyed specifically about their relationships with the men who fathered their first child. 1514 of those women had become involved with their baby-daddies while on no form of hormonal contraceptive and 1005 had been on progesterone/estrogen pills, with another 278 on some other form of hormonal bc, such as progesterone only pills. The women were asked whether they were still in a relationship with the man who fathered their first child, how long the relationship had lasted, their levels of general and sexual satisfaction as well as the attractiveness of their partners. They were also asked about their sexual behavior, such as the rates at which they rejected their partner's sexual advances and how often they had compliant sex, defined as, 'had sexual intercourse with [her] partner even though [she] didn't want to.' And yes, that definition includes both sex for the sake of the other person's happiness and coercive sex. The researchers did make a distinction between those behaviors in the analysis.
The big results: women in ongoing relationships who were on the pill when they paired up had slightly lower levels of sexual arousal with their partner, satisfaction with that partner's 'sexual adventurousness,' sexual attraction to their partner, and sexual proceptivity (dictionary.com tells me that means, "pertaining to preoccupation and purposefulness, esp. pertaining to sex." In the evo psych world it seems to be used to mean women's sexual flirtatiousness/aggression.) And by slightly I mean that the scores (on a scale of 1 to 9, with 1 being completley unsatisfied and 9 completely satisfied) are: for sexual satisfaction, 6.07 +/- 0.062 for non oral contraceptive users vs 5.91 +/- 0.068 for users; for sexual adventurousness, 5.82 +/- 0.064 for non-users and 5.62 +/- 0.071 for users; for proceptivity, 3.80 +/-0.034 for non-users, 3.72 +/-0.044 for users; and for sexual attraction to their partners, 3.35 +/-0.04 for non-users and 3.20 +/- 0.037 for users. So...basically very small differences that are almost within the error of the measurement. The results are similar but in the other direction for other measures of the women's satisfaction with their partners, such as their opinion of said partner's faithfulness, intelligence, and support. The sexual behavior scores are basically identical, with the exception of body attractiveness, which the contraceptive using women rated slightly lower (but again by less than a fifth of a point). Even when adjusted for other factors such as relationship duration, the differences are less than 1 point. Of the women who's relationships did not last, those using contraceptives at the time they started the relationship tended to have lasted longer with their partner.
The sample size is large enough you could argue that those results are statistically significant, but in terms of how use of oral contraceptives will influence your actual happiness with a long term partner? You can probably assume the effects will be negligible. The end conclusion of the authors is that while there may be some (very small) loss in sexual satisfaction among oral contraceptive users, it was balanced by an increase in relationship satisfaction. Of course, there's one glaring hole in the study that I haven't even gotten to yet. The golden rule of statistics is this: correlation does not equal causation. Even if we accept that the differences are significant, the assumption that the reason the women have different relationship is due to their use of contraceptives is presented with no evidence in support of it.
There's no information in the paper about the age of the women when they formed these partnerships, or their reasons for choosing to take or not take oral contraceptives. Nothing about their potential use of other forms of birth control (the supplementary data does note that, not surprisingly, the women not using oral bc had more unplanned pregnancies, but the authors don't really examine that any further). Presumably demographic data was taken from the women, but it isn't in the study, and demographics in this case is important, because more than half of the sample comes from a country - the US - in which access to healthcare, and therefore oral contraceptives - is not universal. There's a brief analysis of regional differences between the women from the US and the Czech Republic, where healthcare is universal, which shows higher rates of separation in the US for women not using birth control, but again no examination of the potential social factors influencing that outcome.
In other words, I'm calling bullshit on these conclusions. The study design lacks the necessary information to support them and in the absence of a more nuanced analysis of women's choices, which in real life tend to be more complicated than, "I'm ovulating so today I will only accept advances from/flirt with men with broad shoulders and an immune system dissimilar to mine," it just reads like what most evo psych is: justification of the authors' pre-existing assumptions.
Dr. Pisaster has a doctorate in biophysics, not actually anything sexy. She does however enjoy having sex, reading about sex, and talking about sex. Especially when she's had a little whiskey.