Myth or Fact: Women’s Menstrual Cycles Synchronize if They are in Close Proximity for Large Amounts of Time

The belief that this occurs is widely known. In 1999, one study reported that 80% of women believe this phenomenon occurs and 70% of them find it pleasant to have this be the case. The truth, like so many other things in science, is controversial. The main body of evidence, however, suggests this is nothing but a myth and it’s really just random chance when this synchronization is occurring.

Which reminds me of this classic from The Onion: Lilith Fair Performers, Attendees Achieve Largest-Ever Synchronized Ovulation.