On January 1, 2011 I did a post on Menstrual Cycle Synchrony, which refers to a process whereby the menstrual cycle onsets of two or more women apparently become closer together over time after those women start to live/work in close proximity to each other. However, a comment on that post (from Martine Frampton) got me thinking more about this. She said that “‘synching’ is urban myth”, and referred me to a podcast interview with anthropology professor Dr. Kate Clancy.
In 1971 Martha McClintock published the first study on menstrual synchrony among women living together in dormitories, and she hypothesized that pheromones could cause menstrual cycle synchronization. Several subsequent studies also provided support for the theory of menstrual synchrony.
However, recent studies have apparently not supported this theory. Wikipedia states, “After the initial studies, several papers were published reporting methodological flaws in studies reporting menstrual synchrony including McClintock’s study. In addition, other studies were published that failed to find synchrony. The proposed mechanisms have also received scientific criticism. A 2013 review of menstrual synchrony concluded that menstrual synchrony is doubtful.”
[The 2013 review is Darwin’s Legacy: An Evolutionary View of Women’s Reproductive and Sexual Functioning, 2013, by Amy L. Harrisa & Virginia J. Vitzthumab].