Here’s an email I sent to some of my friends based on an piece I heard on The Naked Scientist:
This group did a study and found that women who were lap dancers and not on the pill (ie they had a normal menstrual cycle) go more tips on their fertile days. (I can’t imagine the grant application process for that study. “Yeah, we need to study strip clubs…this is important, somehow….”)
So another group wanted to explore this. They selected a bunch of women who were not on the pill and told them to wear a t-shirt to sleep during their fertile days. (No perfume or garlic allowed on those days because it would bias the results. Also, they had to bathe with non-scented soap) Then they had to wear a t-shirt to sleep on their menstruation days. Then they got a bunch of guys to sniff the shirts. (This isn’t the first time I’ve heard of a t-shirt sniffing test in science. How do they get people to sign up for these???) After testing their saliva before and after the sniffing, they found that the men had increased testosterone in their system during the women’s fertile period.
So, not only do woman get hornier during their fertile period, they apparently “force” guys into it the same state. Makes sense from a biological point of view. Increased changes of offspring. And, in the modern day, more tips for strippers. (Well, lap dancers – I think you had to be within sniffing distance) One unintended consequence: when men sense other men with elevated levels of testosterone, they have an increased chance of getting into fights. Probably to ensure the female gets the offspring with the best genes.
And here’s some of the response from our good friend, Duffy, a sociology PhD candidate:
The first and most influential study in the field on this now-hugely-popular topic (Simpson & Gangestad, if I remember correctly, somewhere around the hear 2000) actually studied it from the other direction, with olfaction and t-shirt sniffing. They had men wear tshirts instead and found that women can actually pick more symmetrical men (supposedly the ones with better genes who are more attractive) just by smelling them; they can also pick men who have the most complementary Major Histocompatibility Complex to theirs (MHC-1, which is an indicator of genetic compatibility). Again, the pill actually ruins everything and reverses this, them pick the LEAST compatible men with respect to MHC-1.
Also, more fun stuff about the ovulatory cycle — during the fertile phase (compared to the luteal phase) women actually dress to look sexier (e.g. show more skin), prefer men with more masculine features (e.g. a more square jawline), and are more highly skilled at picking up flirting nonverbals. In the luteal phase they dress more conservatively and prefer more babyfaced men. In truth, it’s not all about the best genes — it’s about conditional mating strategies, which I’ll explain when I haven’t already typed out an entire email essay for you, haha.
Which leads me to wonder how much free will we actually have? At what point are we being controlled by hormones and at what point are we making our own decisions? I’m dang near 100% sure that those women in the second study Duffy mentions aren’t consciously thinking, “I’m ovulating! Better dress sexier!” First of all, most women I know aren’t monitoring when they are ovulating unless they’re actively TRYING to get pregnant. Second, over the course of a woman’s fertile years, a huge percentage of the time that she’s ovulating she will actively be trying to remain free from pregnancy. (For example – probably 100% of the time – from, say middle school through the end of college – at least) Yet there they are behaving in ways that will lead to an outcome they don’t want. At the same time, no guy is, upon coming close enough to smell a woman, thinking, “Oh man, she’s ovulating! It’s gonna be so easy to convince her to have sex!” And, in fact, while his testosterone levels may be elevated, he will not know why he finds himself so attracted to this woman.
So we’re left wondering how much free will this leaves us? After all, if something as mechanical as a menstrual cycle is dictating how women dress, who they are attracted to that night, and how easy it will be to bed them, where does that leave us? Of course, it’s not automatic, so we do have free will. Every day people will find themselves sexually attracted to people and they don’t act on it, but something just seems sinister about the fact that it’s all based on chemicals rather than a person’s personality. Let’s say in a scenario where two women are equally visually attractive (and with the same general personality), but one is ovulating and therefore is the one the guy ends up with – it could potentially lead to a completely different life if this one meeting led to marriage. Had the chemicals been reversed, the man would have ended up with the other girl. This just seems wrong…