Ask the average person how the menstrual cycle affects women's moods, and you're likely to get an earful about PMS, or premenstrual syndrome. While it's true that PMS symptoms are common although not as stereotypical as usually believed , new research is finding women's behavior shifts at another point in the reproductive cycle: ovulation.
Two new studies in the November issue of the journal Evolution and Human Behavior find that women get a little wilder during their most fertile days of the month.
One study found that fertile women are more open to the idea of hooking up with a stranger or acquaintance, while the second found that women with less masculine-looking partners are more likely to lust after strong-jawed men during fertile days than women with partners with manly mugs.
The new studies are two of more than 20 that have examined the effects of ovulation on the way women dress, talk and think. While it's not yet clear if or how these temporary changes affect women's relationships in the real world, they may by a key to humanity's past.
Until about a decade ago, most research on the menstrual cycle focused on PMS, which occurs after ovulation and before menstruation. Few people had investigated whether ovulation affected women, Martie Haselton, a psychology professor at the University of California, Los Angeles, told LiveScience. One reason no one had tackled the question is that researchers in human evolution had long assumed that ovulation didn't matter much in humans.
