A period shared is a period halved.

If you’ve ever lived with female friends or spent an inordinate time with your crew, you’ll know that the only solace to a visit from aunt flow is that you generally had one or two pals experiencing it at the same time. You could double up on the chocolate, ice-cream, and rom-coms and ride out the horrors of the crimson wave together. Apologies for the visuals. And while at the time, having someone experiencing the same thing seems like a gift sent from the lady gods, it turns out the reason for synchronisation is a little bit more odd and rooted in evolution. The idea of synchronization was first documented in a study in published in Nature in 1971. That study recorded data on the menstruation of 135 American college students living in a dormitory. The study continued for approximately 8 cycles and it noted an increase in synchronisation for roommates and close friends. The authors of the study claimed the reasoning was pheromone communication which occurred due to the vast amount of time friends and roomies would spend together. Now, according to The Sydney Morning Herald, “socially mediated synchrony” is studied widely amongst close friends and the animal kingdom. A theory now states the phenomenon exists because synchronisation leads to females becoming sexually receptive at the same time. Basically, in the animal kingdom, all the lady lions, and the lady apes would sync up to avoid being monopoloised by a single dominant male – making it easier to engage in polyandry. It basically happens to protect one Hun from being singled out by the male. The study states if all females are sexually receptive at the same time then it is difficult for a male to control the sexual access to a particular female at all times. So there you have it, the next time you’re curled up with your mates weeping at the ads, elbows deep in a tub of Ben and Jerrys, at least relish in the fact that this is nature's way of protecting you and the #squad from the boys.