Everything has a history, including menstruation. Shown here is rock art from Western Australia’s indigenous peoples depicting two women dancing and menstruating.
The cultural history of how societies have dealt with women’s menses is fascinating, but so too is the research done by evolutionary biologists. We have not all experienced periods in the same way throughout time. For most of human history, people were hunter-gatherers, and it turns out monthly cycles were likely very different.
For one, menstruation probably started much later than it does for women in health-rich countries — age 16 versus the 12/13 year-old average in today’s United States. By age 19 our hunter-gatherering ancestors’ cycles meant ovulation (the first three or so years women’s ovaries weren’t releasing eggs), leading to pregnancy. Mothers likely wanted to limit the number of small children in their groups — anyone who has travelled with babies might understand why.
Fortunately, since their nomadic and foraging lifestyles didn’t procure an abundance of excess food, nursing would have been a more reliable method of birth control than it is for women today. The lowered calorie consumption might have meant that periods and thus ovulation wouldn’t have easily resumed.
What all this meant was that hunter-gatherers women likely experienced far fewer periods in their lifetimes than most women in health-rich countries nowadays — something along the lines of 150-200 cycles instead of 600. Pretty lucky for them, right? Of course, being constantly pregnant or nursing for much of your life wouldn’t have merited the trade-off, IMHO. Some scholarship suggests that our female forbearers also suffered fewer cancers of the reproductive organs, because their bodies didn’t go through the swings of hormonal changes in estrogen and progesterone as frequently.
One myth that modern research is overturning today is the idea that women living in close proximity synchronize their period cycles. Nope, neither the moon nor pheromones seem to have any affect on women’s menstruation. And since hunter-gathering women were mostly not menstruating, they the ones who were probably didn’t synch up either.
Source(s): _Women’s Bodies, Modern Lives: How Evolution Has Shapes Women’s Health_, Wenda Trevathan (Oxford University Press, 2010), chapter 2.
