Dismantling Myths About Menstruation

11:09 minutes

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Saying the phrase “menstrual blood” or or the word “period” can feel almost dirty. That’s because in the western world, people with periods are taught not to discuss this exceedingly normal biological process. Half the world will menstruate at some point in their lives, and yet menstruation remains exceedingly under-studied. 

Biological anthropologist Kate Clancy dug into the history of menstruation research, and the myriad misconceptions about it, while working on her book, Period: The Real Story of Menstruation. What she found was a lack of basic understanding of the biological process, from physicians and menstruators alike. 

Clancy speaks with guest host Maddie Sofia about the misconceptions of a “normal” menstrual cycle, and other persisting period myths.

Further Reading

Segment Guests

Kate Clancy

Kate Clancy is the author of Period: The Real Story of Menstruation, and is based in Urbana, Illinois.

Segment Transcript

JOHN DANKOSKY: This is Science Friday. I’m John Dankosky.

MADDIE SOFIA: And I’m Maddie Sofia.

I’m going to say something, and I want you to pay attention to how you feel when I say it– menstrual blood. Yeah, periods. Maybe you just felt a little uncomfortable. But it doesn’t have to be that way. Periods are just one of the many biological processes out there in the world. Half the population has periods, but menstruation is seriously understudied. And that leads to a lot of misconceptions.

Lucky for us there is a new book all about the biology of menstruation, its history, and its future. My guest is Dr. Kate Clancy, biological anthropologist and author of Period: The Real Story of Menstruation, based in Urbana, Illinois.

Welcome to Science Friday, Kate.

KATE CLANCY: Thanks so much for having me.

MADDIE SOFIA: I’m excited. I’m excited. OK. So many of us who have periods are taught that they’re kind of gross or useless or they shouldn’t be talked about. But at the beginning of your book, you write, “Menstruation is a wild process that should captivate and delight.” Can you make a case for that and why you feel that way?

KATE CLANCY: I hope I can. Because I certainly did spend an awful lot of words trying to do that in the book. So I’ll try to give you the condensed version here. The thing that is so interesting to me about periods is that it is something that occurs so regularly. It is this incredible process, this cyclic process, of growth and differentiation and regression that happens upwards of 400 times in a lot of people’s lives.

And what’s incredible to me is that there aren’t a ton of processes like this, where you actually see the effluent, you see the output, and can engage with it in a really nitty gritty way. There’s a reason that phobias of blood don’t tend to occur in menstruating people. And it’s because we are so directly engaging with blood and clot and lymph and other things all the time. And so we get this very real-time granular sense of what’s happening in our bodies.

And I think the fact that we get to know that this process is happening in the body, but then also see some of its output and see how it changes over our lives, is just fascinating.

MADDIE SOFIA: Yeah. And I think it’s important to talk a little bit about why menstruation is so understudied. I know that’s a big question. But talk to me a little bit about that.

KATE CLANCY: I mean, there are a couple of different reasons why menstruation is understudied. One of the big ones, of course, is menstrual stigma itself, which is a really persistent issue within Western science. The way that stigma tends to manifest is through silence, through lack of communication, through removing people from daily life who might be experiencing menstruation.

And so there are a lot of ways where we just haven’t even known what questions to start asking because so many people have such limited ideas about what it even is. The number of times I’ve encountered people who don’t know the difference between menstruation itself and a menstrual cycle is huge. So I usually have to coach people who are research participants on my studies. And I’ll say, OK, so about how long is your menstrual cycle? And they’ll usually say four or five days.

And I’ll say, well, actually, you’re probably telling me how long your menstrual period is. Your cycle is the first day of one period to the first day of the next. And it just blows open that, even some of these really basic things that, as a scientist, I’ve come to take for granted, these small language shifts are things that we don’t even have in our regular discourse.

MADDIE SOFIA: Right. I mean, tell me a little bit more about some of those big misconceptions that you wanted to dissuade in this book. I know there are a lot of them, but give me your favorite.

KATE CLANCY: I think one of the biggest and most persistent myths– and I think it’s still very much in our popular understanding of periods, even though I don’t think that this is where the science is anymore– is that periods are about removing bad things from your body. It’s about flushing out the system, getting rid of toxins. There’s a lot of different ways that people talk about it, but it’s about removing yucky stuff.

And really, the effluent is this side effect of the cycling itself. And so really, instead of thinking about it as you’re removing gross stuff from your body, actually what you’re undergoing is this really amazing healing process of renewal of your uterus every, let’s say, anywhere from 25 to 40 days.

MADDIE SOFIA: I want to focus on this one idea you talk about a lot in the book. And that’s this idea of a “normal period,” that you can find some representative average cycle amongst the menstruators. Can you explain that to me?

KATE CLANCY: Sure. There’s sort of this dorky thing of understanding statistical distributions or statistical averages that we probably have at least a little bit of familiarity with from math and stats classes in school. And it’s this idea, you take a whole bunch of numbers and you figure out where the mean is. The problem is is that using a mean to have any type of biological meaning presumes that there’s going to be a normal distribution. Meaning a more or less equal number of people on either side, with the majority of people hovering around that mean.

But that’s not actually how a lot of measures in the menstrual cycle work. You can see a bimodal distribution. So a lot of clumping at the low end and a lot of clumping at the high end. The mean is not actually all that informative for a lot of things. And we do lots of things statistically to handle it. We do things called log distribution and other stuff. But at the end of the day, it’s not normally distributed. So understanding an average and constantly representing that as the norm is inaccurate.

MADDIE SOFIA: And I think it’s important, just this idea of normal, for us to examine it. I mean, in many areas of science, including the science of menstruation, normal is based on a very specific population. It often excludes people of color, trans folks, disabled people– basically, anyone outside of this white cis population that Western science really likes to focus on. I mean, how does this harm our understanding of periods?

KATE CLANCY: Right. In exactly the same way that it does in all of these other ways.

If you take a selected group of people, a sample of people that’s drawn from a small proportion of, like you said, often cis, white, straight, able-bodied– other types of potentially privileged bodies– we take that average, and then we say that’s what normal is and all of you must conform to that or else we’re going to put you in the pathological bucket and you don’t ever get to be in a healthy bucket, then that means that everyone ends up developing these really skewed ideas of what it means to be healthy or normal, including the people who are in that self-selected group because of the fact that this normal distribution thing is kind of a farce to begin with.

So it’s actually harmful for everybody.

MADDIE SOFIA: Right. I remember being like, I got my period like a little bit later in life and all my friends had it, and I was like, man, I guess I’m a late bloomer, and felt weird, and weird things about my femininity. And that is true for a lot of people.

KATE CLANCY: One of the papers that I read as I was writing this book was a study that asked people– who were adults– asked, when did you first get your period? And did you feel that you were early, late, or right on time? And pretty much everyone thought that they were early or late. Nobody thought they had actually gotten their first period on time.

And yet, the difference between the age ranges of the people who said, oh, I got my period so early or so late was about half a year. So it was like 9 to 11 and 1/2 were saying, oh, my gosh, my period was way too early. And then 12 to 14 was saying, oh, no, my period was so late.

So that means nobody gets to live within that norm and feel like they’re normal.

MADDIE SOFIA: And I think it’s also, when we are talking about it, it’s like comparing ourselves to this like ridiculous standard. But you talked a lot in this book about how we just don’t talk about it. And that’s a very Western medicine, Western view of menstruation. How does this compare to other cultures? Is there a culture where you’re like, man, I’d really like to menstruate in that culture?


KATE CLANCY: I think what I would say is there is so much more variability out there in terms of how different cultures think about and interpret periods culturally and biologically. And I think one of the biggest harms of Western science and Western anthropology– I’d say as an anthropologist– is that we take our lens and our way of seeing the world and then we say that we’re being objective and pretend we don’t have that lens. Then we go to all these other populations, and we’re informing our interpretation of what they’re doing with our lens.

So for the longest time, we saw menstrual seclusion practices– so going somewhere when you have your period– somewhere away from other people, as negative. And we were like, oh, my gosh, those terrible, sexist populations. And now we’ve seen there’s so much more variability.

There are some times that menstrual seclusion practices are harmful, are problematic. But there are many, many, many, more across many other populations and many other cultures where menstrual seclusion is about getting a little bit of a break, concentrating your power, taking some time to yourself. And that’s a really different way of thinking about periods, and certainly one that I would love to adopt.

MADDIE SOFIA: Absolutely. Absolutely. I remember you talking in the book about how it would be nice to hang out with other menstruating people and take a break and maybe talk about what you’re experiencing, and it being very uplifting. And I was like, wow, that is so much different than what a lot of us experience.

KATE CLANCY: Right. And instead, what we do is we pretend that it’s not happening.

MADDIE SOFIA: OK, Kate, I have one more thing I want to do. It’s a lightning round, so brace yourself. I want to tell you some things that I’ve heard about periods. And I want you to tell me– and I know this is going to be hard because we’re going to leave these caveats– like, true or false, right?

KATE CLANCY: I’ll do my best.

MADDIE SOFIA: OK. Periods sync up. Like, when a group of menstruating people are living together or spending their time together, there’s like a uterus that takes over and they all sync up. Is that real or not real?

KATE CLANCY: It’s false.

MADDIE SOFIA: OK. All right. What about PMS? This idea that everybody gets really moody or experiences these hormonal shifts that come out as emotional whatever you want to say before your period, is that real?

KATE CLANCY: It’s not universal.


KATE CLANCY: So it’s false in the sense that it’s universally experienced by every person who has a menstrual cycle. But do people experience mood changes premenstrually? Absolutely.

MADDIE SOFIA: OK. And then my last one is– that we’ve touched on a little bit, but I still want to ask you it– this idea that menstrual blood is useless.


MADDIE SOFIA: OK, Kate Clancy, that is all the time we have now. I would like to thank you very much for coming on the show and talking with us.

KATE CLANCY: No, it was awesome. Thanks for having me.

MADDIE SOFIA: Dr. Kate Clancy, biological anthropologist and author of Period: The Real Story of Menstruation, based in Urbana, Illinois. You can read an excerpt from this book on our website, sciencefriday.com/period.

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Meet the Producers and Host

About Kathleen Davis

Kathleen Davis is a producer at Science Friday, which means she spends the week brainstorming, researching, and writing, typically in that order. She’s a big fan of stories related to strange animal facts and dystopian technology.

About Maddie Sofia

Maddie Sofia is a scientist and journalist. They previously hosted NPR’s daily science podcast Short Wave and the video series Maddie About Science.

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