The Evolutionary Role Of PMS?
Professor Michael Gillings of Macquarie University argues that premenstural syndrome could have served to break up infertile couples.
AsianScientist (Aug. 20, 2014) - A brave scientist has sought to answer a question that has baffled for centuries: why do women get premenstrual syndrome (PMS)?
Professor Michael Gillings, from Macquarie University, believes that in our evolutionary past there was a hidden selective advantage to PMS, because it increased the chance that infertile pair bonds would dissolve, thus improving the reproductive outcomes of women in such partnerships.
"In the past, women had many fewer menstrual cycles than women in modern societies, because they did not have control over reproduction and were either pregnant or breastfeeding most of the time," said Prof. Gillings.
"Imagine that a woman was pair bonded with a sterile or infertile male. Then, even in the past, they would have had regular cycles. If women in these relationships exhibited PMS and this increased the likelihood of the pair bond dissolving, this would be a huge reproductive advantage. This simple phenomenon might explain the frequency of PMS. There are various lines of evidence from DNA and behavioral studies that confirm this idea."
The hypothesis was supported by the high heritability of PMS, and the fact that gene variants associated with PMS can be identified, not to mention the data that show animosity exhibited during PMS is preferentially directed at current partners.
"Under this view, the prevalence of PMS might result from genes and behaviors that are adaptive in some societies, but are potentially less appropriate in modern cultures," he said.
"Understanding this might help the management of PMS and will help change attitudes, for example, towards cycle-stopping contraception. PMS is a simple and natural behavior that arose as a consequence of our evolutionary past."
PMS affects up to 80 percent of women, and has been observed in all countries where PMS has been investigated, dating back to the time of Hippocrates. The levels of disruption ranges, and can lead to personal, social, and economic costs. Symptoms include anxiety/tension, mood swings, aches and cramps, cravings and disinterest in usual activities.
The article can be found at: Gillings (2014) Were There Evolutionary Advantages to Premenstrual Syndrome?
Source: Macquarie University; Photo: Shutterstock.
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