Have you ever heard the theory that when women live in close proximity with each other they tend to menstruate at the same time?

Think that it is a myth? Think again!

Apparently, this is a fact and it is said to be an evolutionary phenomenon.

This is a phenomenon that medical science only became aware of in the last 30 years. But in fact, it has already been documented first among nuns.

Apparently, if a group of women were to live close to each other for a long time, their menstrual periods will initially be asynchronous. However, after a while, some would have shorter or longer periods until all of them have their periods at the same time. In that way, they’ll then be fertile at about the same time as well.

The reason for this phenomenon is still not clear but one of the explanation scientists gave was that since a woman is only fertile for a small part of each month, and if in a tribe, all the women are fertile at the same time, it would mean that men of that tribe will have less chances of having alot of children by a lot of women.

More importantly, if women had different cycles, the men might pick the wrong girl to fertilise. i.e. no offsprings *gasp!* However, if all the women are sychronised, then he can’t be wrong cos they are all fertile at the same time. So confirm can haf offsprings.

This way, it compensates for congenital male cluelessness about women’s bodies. =p

I’ve checked this with several other website… and they all agreed that the phenomenon is real but most cant really give an explanation why. Wonder wat’s the mechanism behind all this.. I mean… we gals wun go ard telling each other when our periods start and everything. So somehow, our bodies communicate to each other and synchronises our periods without us knowing! hmm… *update* from the website below, apparently it’s due to a scent females give out. read how they test out the scent theory. pretty gross i think

The article i got the above explanation from is here. It has loads of interesting scientific issues on sexual selection if you are interested to read more.

oh and here’s wat another website says:

there are women who are menstrual pacesetters–they made other women conform to their cycles. So if those women are around you (if you are a girl) beware! Heh.

men also have an effect on women’s menstrual cycles–and not just because they make women pregnant. Women who associate with males frequently find that their periods become shorter and more regular.

hmm do i see males cringing? got information overload anot? =p Gers.. does this article help solve a bit of mystery regarding the synchronisation now? =)