Menstrual synchrony

or, what does my ovulation depend on?

My friend Magda, a lecturer at one of Warsaw University?s departments, told me a following story:

As a student I lived in a student dorm. I had two roommates. It scared me a little at first ? living with strangers. But we got on well, after a while we even became friends.

That?s why we decided to spend some holiday time together ? the three of us plus one more girl. We went to the montains, it was a very good trip. On our way back we stopped at a lake. I told them: take a dip, I?ll just sunbathe a little. It was because my period had started the day before. It turned out that so did Olka and Boena?s! Only Kaka, who didn?t live with us, could swim. All three od us started menstruating on the same day!

Research confirms that women who live together begin menstruating simultanously. This phenomenon was observed in Europe already in the 19th century: women who lived together in workhouses, penitentiary institutions, and later student dormitories began menstruating at the same time ? their cycles synchronized. However, dr Martha McClintock was the first scientist who, in the second part of the 20th century, started examining this old phenomenon.

Research among female students

This American biologist investigated the influence of the environment on physiology. She was concerned with the impact of the acquired on the innate. Fascinated by the phenomenon of female menstrual synchrony she carried out research among students of American universities. What were her findings? Her research in a student dormitory in an American college for women confirmed observations of many women - menstrual synchrony was a fact! To explain this phenomenon in 1972 she presented a thesis that women who spend time together in limited space secrete an odourless, volatile pheromone, which causes their menstrual cycles to synchronize.

However, while some later studies carried out by scientists supported her thesis, others undermined it. Many criticized her claiming that either synchrony is a scientific fact, and then it should be observed every time, or it is not. McClintock was convinced that since people are social creatures, more variables, besides living together, have influence on them. She raised a question: do relations among the women living together ? sympathy/hostility ? influence ovulation? If menstrual synchrony is a fact, why does it sometimes occur and other times not?

Partner?s influence

After further investigation Martha McClintock concluded that other women?s pheromones are only one of the factors our body takes into account when deciding about ovulation. She divided these factors into internal (stress level, tiredness, physical state) and external. One of the external factors is being in a a stable heterosexual relationship. Women living with men ovulate more regularly. What is more, sexual pleasure has impact on ovaries and may for example change the time of ovulation by releasing LH (luteinizing hormone). (So take caution! ? satisfactory sex can trigger ovulation and lead to getting pregnant during a time when it was ?absolutely impossible.?) Due to considerable influence of our partner on our ovulation, the phenomenon of menstrual synchrony usually concerns women living together: friends, room/flatmates or partners.

Wise body

Second important external factor is how we feel in a given environment (whether we feel sympathy or antipathy). Our body, deciding about fertility, tries to ensure the best conditions for delivering and raising a child. People ? as we all know - are social animals and women are especially sensitive to emotions and relations within their ?herd?. That is why ? as research has demonstrated ? the phenomenon of menstrual synchrony depends on relations among the women living together. It isn?t enough that they live together ? it is vital if they like each other or maybe the opposite. It turned out that two roommates in a student dormitory who disliked each other became completely asynchronous ? when one ovulated, the other menstruated, and vice versa! Their bodies didn?t want to be fertile at the same time as the disliked roommate, to avoid pregnancy in an unauspicious environment. Along the same lines ? the perspective of rearing chlidren in the company of a beloved friend is very tempting. Hardly surprising ? true friends are those who count in our lives.

So, does menstrual synchrony exist? Undoubtedly yes. It is just a more complicated phenomenon than it appeared at first glance.

What about you? Are you familiar with it?




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