So, women's periods DON'T actually sync up when they live together

Our lives are a lie

It's kind of a given that women who live together are all on their period at the same time, whether it's your mum, your sisters or your female flatmates. PMS is rife at the same time every month, the tampons all run out, and you're all eating a lot more chocolate than usual.

This belief is based on a study of 135 female undergraduates who shared a dorm at college, carried out by Martha McClintock in 1971. She found that close friends and house mates saw the start dates of their periods fall from within eight or nine days of each other to just five. Ever since then, we've taken it as read that we sync up with the other females we live with.

But it turns out that it's nothing more than a coincidence when this happens, as most of the research since this study hasn't found the same phenomenon, The Guardian have reported. Here's everything you need to know about periods.

We're not quite sure what to do with this information. Have we really been lying to ourselves this whole time? We honestly don't link up with other girls when it's that time of the month??

Unfortunately, the evidence to support this statement is pretty damning. According to The Guardian, most of the studies that have tried to replicate the conditions from McClintock's original 1971 study found no synchronicity between women at all. None. It's argued that because of various factors affecting your period, such as stress, weight loss or weight gain and illness, for example, the start date is variable. So it really is just a coincidence when you and your bezzie's period falls on the same day.

Well, there you have it - despite it seeming like you're so in sync with your female housemates, you're really not as close as all that.

We can still all binge on chocolate when it does happen though, right?