As ever science is a bit behind when it comes to women’s bodies. Scientists aren’t sure whether or not women’s bodies actually sync up during menstruation.
The phenomenon of period-syncing, first documented in 1971, is also known as menstrual synchrony. Despite what science says, more or less anyone who’s ever had a period will have experienced it.
So why can’t scientists agree about whether or not women’s periods tune into each other? The main reason is that, truthfully, science isn’t completely sure how women’s bodies work.
What is menstrual synchrony?
Back in the 70s when this was looked into for the first time, Martha McClintock, who authored the study, found that ‘social interaction’ amongst women was the reason behind all the synching up. Another study in 1998supported her hypothesis and concluded that pheromones were involved, with women signalling to one another via invisible airborne chemicals.
However, both of these studies have been heavily criticised because of how they analysed data and dismissed because they were too small and did not observe the cycles of a large enough number of women. McClintock’s only reported based on a sample size of 135 women.
So, why do women get their periods at the same time?
Another one of the main theories about menstruation and synchronisation is that it’s rooted in evolution. The idea is that it was beneficial to the human race for all the women to be fertile at the same time for several reasons. Some people think this is because no particular female was fertile at a particular time, and singled out by the males as a result. Others think that it was so that prehistoric women could retreat together during menstruation and stay safe from predators.
Today there’s actually a school of thought which says that the power of menstruation can be harnessed as a force for good, think of the recent discussions about ‘period leave’.
Writing on Mystic Mama, Clarissa Pinkola Estes says that modern woman can use her menstrual cycle to her own advantage by seeing it as a message from her body:
‘Women from ancient times as well as modern aboriginal women set a sacred place aside for this communion and inquiry. Traditionally, it is said to have been set aside during women’s menses, for during that time woman lives much closer to self-knowing than usual; the membrane between the unconscious and the conscious minds thins considerably. Feelings memories, sensations that are normally blocked from consciousness pass over into cognizance without resistance. when a woman takes solitude during this time, she has more material to sift through.’
‘However in my exchanges with tribal women from North, Central and South America, as well as female progeny of some of the Slavic tribes, I find that ‘women places’ were used anytime, not just during menses, and more so, that each woman often had her own ‘woman place’, consisting of a certain tree, place at the water’s edge, or some natural forest or desert room or ocean cave.’
‘Much of modern woman’s premenstrual crankiness is not just a physical syndrome but it equally attributable to her being thwarted in her need to take enough time away to revivify and renew herself.’
The truth is that nobody knows whether or not period synchronicity is ‘a thing’. Scientists can’t even agree on whether or not pheromones exist, let alone how they work!
Science aside, what’s certain is that many women report, anecdotally at least, that their periods have synched up with their friends, colleagues and flatmates and we can make of it what we will.
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This article originally appeared on The Debrief.