Blaming your girlfriend's mood swings on her period is so last century. According to UCLA psychology and communications professor Martie Haselton, ovulation is "the new time of the month."
"This research... [has] been sort of a mini-revolution in understanding women's sexuality," Haselton says, referring both to her own work and to studies done by fellow evolutionary psychologists. Just before ovulation, she's found, women avoid contact with male kin. Their voices rise in pitch. And most recently, in a study published in November's Hormones and Behavior journal, she and graduate student Christina Larson determined that during this highly fertile window, women devalue relationships with partners that have long-term potential and feel closer to partners with more sex appeal.
Because, according to Haselton's dual mating hypothesis, women have evolved to want a hot, masculine lover and a high-status, caring husband -- and few men are both.
If that dichotomy sounds unreasonable or offensive, join the club. Evolutionary psychology remains a contentious discipline, seen by some as a legitimate field of study and others as a murky pseudoscience.
A few weeks ago, a burp from the mass indigestion caused by evolutionary psychology went viral when blogosphere outrage -- particularly from the scientist and feminist corners -- led CNN to remove an article from its website summarizing the results of a study about how ovulation affects voting (Fertile gals love the GOP!).
Haselton calls the retraction "stupid" and took to Twitter in a #healthtalk forum to defend the author behind that research, University of Texas at San Antonio assistant professor Kristina Durante, with whom she coauthored a 2006 study showing women dress more attractively during ovulation.
"People like to think of voting as cold and rational," Larson says, "which of course is ridiculous. It is influenced by biology, but not to the exclusion of other factors."
In spite of this public show of support, however, Haselton purses her lips at those in her field, like Durante, who rely on self-reported menstrual cycle data instead of testing subjects, as she does, for the hormone that indicates the onset of ovulation. Haselton also says her research doesn't invite vehement backlash as Durante's did because, "When it comes to sexuality, people buy it."
But not everyone does. Meredith Reiches, a Harvard lecturer in Human Evolutionary Biology, says several results in Larson and Haselton's most recent study are only marginally significant, statistically, and that Haselton's work may mistake culture for biology, perpetuating unfortunate stereotypes.
When it comes to female behavior, drawing the line between nature and nurture is fraught with uncomfortable precedent. In his 1889 book, The Evolution of Sex, the Scottish scientist Patrick Geddes famously rejected the pursuit of gender equality by declaring, "What was decided among the prehistoric Protozoa cannot be annulled by Act of Parliament."
In 2010, on the lookout for all the modern-day Geddes in her own field, Reiches started an informal monthly Feminism and Evolutionary Biology Reading Group of five to ten of her fellow academics, whose expertise ranges from evolutionary biology and psychology to law, philosophy and cognitive neuroscience.
"The stories that reinforce power structures stick around," Reiches writes in an e-mail, before listing numerous places in this newest study where Haselton's science seems unsound.
Kate Clancy, an assistant professor of anthropology at the University of Illinois at Urbana-Champaign who collaborated with science blogger scicurious on tandem posts dissecting and railing against Durante's voting research, also questioned the biases behind Haselton's work, which draws conclusions about all of humanity from a small selection of so-called WEIRD (Western, Educated, Industrialized, Rich, Democratic) UCLA undergraduates.
"The way we think about love and relationships is different from the way an agriculturalist thinks of it, or a forager, and probably quite different from our ancestors," she says in an e-mail. "So the question is how something could have evolved (this variation in romantic feelings and attraction) if the phenomenon (modern, Western conceptions of romance, monogamy and love) may not have existed in the past."
Although Haselton and Larson maintain that the attitudes of the 108 women they studied signify traits that are universal and biological, not confined to 21st century university hookup culture, they're not altogether convincing. The primary questions asked in their study -- Do other women find your partner desirable? How would you rate your partner's current and future social and financial status? -- reflect qualities that, in spite of this "dual mating hypothesis," seem both arbitrary and subjective, regardless of the time of month.
Reiches quite rightly points out that, with her dual mating hypothesis, Haselton "makes a pretty big assumption about women being attracted not to a particular mate but to some kind of ideal or central tendency." Reading over what the evolutionary psychology literature defines, vaguely and appallingly, as the type of masculine sexiness all women have evolved to be attracted to -- "masculine face... masculine voices, social dominance" -- it's worth questioning whether this study would have turned out quite differently if done among undergraduates at Bard, not UCLA.
Haselton and Larson do acknowledge the limitations of their work, saying that ovulation influences, but does not determine, behavior. Haselton (and others) also points out that the biggest issue with the media taking offense to studies linking ovulation to certain behavior is the misconception that women are more driven by their hormones than men, a sexist idea that is nowhere to be found in any of this research. She also complains that the mainstream media often reports her work "in a sexier way, in a gossip column-y kind of way."
And perhaps that's true. Reiches and Clancy offer serious critiques, but the popular press isn't always equipped to determine what is or isn't good science. Sexy research like Haselton's and Durante's provides click-bait that offer readers the grown-up equivalent of a horoscope, with slightly more authority: a convenient, cozy narrative to live by, a trickle of meaning to help answer the age-old question: Why am I who I am? Pinpointing who in this chain -- the study subjects, the scientists, the journalists, the readers -- is responsible for reinforcing gender stereotypes isn't always clear.
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Maybe it's all of us.
The real question, though, is what happens when this research truly permeates pop psychology, when a woman puts on a glittery top and happens to click 'Ignore' when her brother calls, and her husband rolls his eyes, saying, "Somebody must be ovulating!"
"I don't know that it's a good thing," Haselton says, "but I think this research really captures people's attention. And I think that people really do want explanations for why things vary from day to day... It's more scientific than an anecdote, for sure."