Take a deep breath everyone, because there’s some medical information out there that’s actually a huge bummer, sigh. As it turns out, science has proven that our periods haven’t been syncing up with our sisters, roommates, and best friends all these years. Periods, evidently, don’t sync up to other periods. What the heck?!
Period synchrony, the idea that two or more menstruating people’s periods will shift to occur at the same time each month after they spend enough time together, has been around for decades. The first study on this supposed phenomenon was published in 1971 by psychologist Martha McClintock. McClintock collected data on 135 women living together in college dorms, and she concluded that over time, their periods became closer together.
But alas, according to a new study conducted in partnership between the fertility tracking app Clue and Oxford University, period syncing just isn’t real. Clue collected data from 1,500 of their app users, narrowed down to 360 users who had periods with some overlap to other users of the app who were connected through some personal relationship. The data reveals not only that periods didn’t seem to sync up, but further that “cycles are actually more likely to diverge (get out of sync) over time.”
A scientific paper all the way back in 2006 found that McClintock’s original study was, in fact, misleading in its conclusions. According to the paper, published in Human Nature, the level of synchrony between the women studies “was at the level of chance.” Welp.
Though this isn’t the first time the myth of period synchronicity has been debunked, it was news to me, and I have to say, I am left feeling pretty bummed out. I ran this new study by some menstruating friends of mine, including my older sister Jenn who was especially unwilling to accept the new data. When we were younger, both of us would have sworn we were synced with each other and/or our other sisters. Jenn says she has too much anecdotal evidence to the contrary of the study to fully buy its findings.
Katherine, a friend of mine, said that it makes her sad to learn that periods don’t sync. She adds that she has a hard time connecting with other women, but knowing that her uterus was reaching out to others and making a connection felt good. Another one of my friends, Kathy, said this information was a relief to her. Kathy noticed that she’d never synced with anyone, and it made her feel that she wasn’t fully able to bond or connect with other women. Because so many people talk about “syncing up” as a way that people with periods measure closeness, the whole concept made her feel left out.
I polled my network on social media on the subject and heard back from several women who were also not yet aware that there are studies out there that demonstrate periods don’t sync, and one of the most common sentiments they expressed was a sense of disbelief. Most of the women said they have a hard time believing that there’s no hormonal or otherwise physical interaction between different peoples’ menstrual cycles. Though I pretty much always defer to the scientific data, I find myself in a bit of denial too!
The idea that periods could somehow interact and cycle together makes the idea of monthly menstruation seem like less of a pain and more of a bonding experience. It’s also comforting to think that as menstruating people spend more time together, their cycles could unify to symbolize closeness between the people involved.
Though the data tells a different story than the women I talked to about period synchrony, it’s still clear that there’s some sort of period-based bond between menstruating people — even if it’s not backed by science.
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(Photos via Max Pixel + WikiMedia Commons + Pexels + Getty)