This week on Stuff Mom Never Told You, Cristen and I explored the stories behind some things women take for common. On Monday, we tackled how some of our most beloved cosmetics became the superstars of the make-up world, and on Wednesday, we delved into one of the most persistent beliefs about the menstrual cycle — that women in close quarters can sync up their periods.

The podcast “5 Iconic Cosmetics” was based on the article of the same name, written by yours truly about a year ago. When I got the assignment, I thought it would be impossible to select just five products. Once I started diving into the research, though, I realized that in terms of immediate impact and lasting influence, the choices were obvious. Max Factor pan-cake, Chanel No. 5, Revlon Fire and Ice — not only did these products change the way women got ready in the mornings, they also revolutionized the way womanhood was sold and considered, in my opinion.

You can find the full list of sources at the end of the article, but I’d just like to give a special shout-out to three sources we leaned on a little more heavily:

• “Fire and Ice: The Story of Charles Revson, the Man Who Built the Revlon Empire” by Andrew Tobias
• “The Chanel No. 5 Story” by Susannah Frankel, The Independent
• “The Man Who Made the Faces Up” by Mary Tannen, New York Times

Get a group of women together for any length of time, and sooner or later, one of them will hypothesize that the proximity will cause menstrual cycles to align. Men believe this, women believe this, and we have one Martha McClintock to thank for the research revolution about this topic. McClintock realized in college that proximity might lead to menstrual synchrony, and she’s used this observation to do some pretty cool research on pheromones. One of her recent projects investigated the effect nursing mothers might have on other women; apparently, we ladies might be sending out signals via menstruation and nursing about whether it’s a good time to have a baby. Interesting stuff, but other researchers think that menstrual synchrony is nothing but a big myth. Most notably, researchers Zhengwei Yang and Jeffrey C. Schank have said that menstrual synchrony is just coincidence. Good luck selling that to menstruating women, fellas.

Our sources for this episode:

• “Do Women Who Live Together Menstruate Together?” by Anna Gosline, Scientific American
• “Menstrual Synchrony and Suppression” by Martha K. McClintock, Nature
• “Regulation of Ovulation by Human Pheromones” by Kathleen Stern and Martha K. McClintock, Nature
• “Menstrual Synchrony” by Norman Swan, Radio National
• “Scent of a Nursing Woman” by Carol Lloyd, Salon
• “Women Do Not Synchronize Their Menstrual Cycles” by Zhengwei Yang and Jeffrey C. Schank, Human Nature (available via library database)

And that was our week on Stuff Mom Never Told You! Thoughts? We’d love to hear from you! Leave us a comment here, or join the fun over on Facebook and Twitter.