In a study published in 2007, psychologists Geoffrey Miller, Joshua Tybur, and Brent Jordan from the University of New Mexico recruited 18 lap dancers to record both their tips, their ovulatory cycles and whether or not they were on the pill. The dancers made entries in an online diary for 60 days. When the psychologists ran the numbers, what they found was that female dancers earned nearly twice as much in tips during estrus — the time in the menstrual cycle when women are most fertile — than they did during their low-fertility times. Moreover, for dancers who were on the pill and whose normal menstrual cycles were thus disrupted, there were no periodic differences in tips. Men saw something in the women who were more fertile and rewarded it with much larger tips!
So what, you may ask?
The reason these findings are more than just a curiosity is that they are consistent with similar other findings that suggest that both men and women respond to signals — primarily visual and olfactory — of which we are all blissfully unaware. These ‘signals’ include the kind of chemical signals we typically associate with non-human animals — pheromones, as well as very subtle differences in appearance.
In the case of detecting when women are most fertile, scientists have long thought that humans were unique among animals in that women’s fertility was hidden from men. This, scientists reasoned, benefited females and their children. Because men didn’t know when a woman was fertile, they couldn’t simply come and go as they pleased and hope to bear children. Men had to stick around and try their luck… well, all the time. In our evolutionary past, this would have led to a greater likelihood of males staying nearby and being useful to females even if females weren’t in estrus.
These findings (and other lab studies that are consistent with this) suggest that the evolutionary arms race was not fully decided in favor of females in this case. Men do appear to be able to discern when women are fertile. Interestingly, it appears that men are not aware of this knowledge.
Ommigod, his major histocompatibility complex is totally hot!!!
But it works both ways. Another famous study of this kind examined female preferences. Researchers had a group of men sleep in the same t-shirt for several nights so that the t-shirt would acquire the man’s particular scent. Then they gave the t-shirts to women to sniff. Researchers then asked the women to choose with whom they would most like to mate, based on the smell of the t-shirt.
A bit of sex education:
Throughout human history, avoiding disease has been one of evolution’s biggest challenges. Biologists believe that sex itself — the combination of two distinct and slightly different genomes — may be evolution’s primary answer to disease and parasite avoidance.
You can think of your immune system as a toolbox designed for fighting off disease agents. Each of us has a similar but slightly different set of tools in our toolbox. By continually mixing together unique combinations of slightly different immune system toolkits, evolution creates highly flexible systems that are moving targets for pathogens. What makes one person or one animal sick may not make the next animal sick. The more mixing there is, the less likely it is that a single pathogen - a virus, for instance - could wipe out the whole species.
As you may have guessed by now, in this experiment, women who sniffed the t-shirts didn’t chose the most fertile males, but the males who had immune systems that were most unlike their own. Said another way, the women in the study interpreted something in the smell of the men’s t-shirts as attractive. What was communicated was not size, physical strength, virility or even intelligence; no, the smelly t-shirt communicated that the “hot” guy’s immune system would provide her off-spring with a unique and powerful defense against potential disease.
Subtle influences such as those described above can alter the economic choices we make on a day to day basis. While it is probably not possible to be aware of all of the influences we are subject to every day, when it comes to how we spend our money, it is perhaps a good idea to take an extra moment from time to time to consider why we are making the decisions we are making. It could be that a moment’s reflection would allow you to make a more informed choice.
At BeyondThePurchase.Org we are researching the connection between people’s spending habits - how do you spend your money and who do you spend it on - and whether that results in more or less happiness. We are also interested in understanding how our personalities, our life histories and the environments we live in influence how we think about and spend money. To learn about what might be influencing how you think about and spend money, Login or Register with Beyond The Purchase, then take our a few of our spending habits (Experiential Buying Scale, Materialistic Values Scale, and Compulsive Buying Scale), and values and personality (Consumer Values Scale Beliefs about Well-being).
Find out more about the studies described above:
Lap dancer study: http://www.unm.edu/~gfmiller/cycle_effects_on_tips.pdf
Sweaty t-shirt: Sweaty t-shirt and female mate choice from PBS
This post was written by Kerry Cunningham. Follow @kerryfc
