630: Things I Mean to Know

Ira Glass

Hey everybody, Ira Glass here, and I am in the studio right now with one of our producers, David Kestenbaum. Hey, David.

David Kestenbaum

Hi Ira.

Ira Glass

So this whole episode came out of something that you have been thinking about, and so I am just going to hand the whole program over to you right now.

David Kestenbaum

OK.

Ira Glass

All right.

David Kestenbaum

It is something I've been thinking about for a while. But actually, it came out of this conversation I was having with Diane Wu on staff here. Diane and I are the two trained scientists on the staff. Before I was in journalism, I studied physics. Diane went to grad school in chemistry.

And she was telling me the story about this time she was at a conference. This was in a small town in Germany. And this Nobel Prize winner, a guy named Harold Kroto, was giving a talk.

David Kestenbaum

For both of us, one of the things we liked about science was this promise that we could understand how the world works-- in a deep way. Everything, except people, of course. Anyway, it was satisfying. I found it comforting.

Diane did, too, until this day she was telling me about, when that changed. She was sitting there with all these students, listening to the Nobel chemist talk. And in the middle of the talk, kind of out of nowhere, he asks this question.

David Kestenbaum

Diane said she really couldn't pay attention to the lecture after that. She was thinking, what do I really know? And also, because she found his particular example distracting, how do we know the earth goes around the sun, not the other way around?

David Kestenbaum

After the lecture, Diane goes home, newly aware of this vast universe of her personal ignorance, just realizing, so many of the things I think are true, they are just things I've heard from someone who probably heard them from somebody else, probably without evidence either. And this sits with her for months, until some point she decides, you know what? Things do not have to be this way. I'm going to do something. I'm going to fix this. She makes this list, calls it "Things I Mean to Know."

One of the things I love about this list is just the total honesty of it. Diane told me she knew, really, as a person living in this world, she should have understood the difference between Sunni and Shia, especially after reading the news all those years. But she was just like, I don't. That was the truth of it.

So Diane makes this list. She actually starts a blog where she's going to answer them, titles it Loose Ends. Then she starts researching and writing the answers, starting with this one, yams versus sweet potatoes.

David Kestenbaum

She writes a very detailed answer to the question, even includes some old botanical drawings. She said it was really satisfying to do.

David Kestenbaum

I asked Diane, what happened? What about the mission? She said the next day, she was going to start on the next question, which was going to be that chemistry thing, the Schottky barrier. But she just didn't get very far.

David Kestenbaum

Diane says she never felt like she gave up. She always figured, at some point, she would get back to it, turn the things I mean to know into the things I know, but she hasn't, which, of course, is the way most of us deal with this. We never figure those things out.

Essentially, Diane had this moment where it seemed like she was going to evolve to a higher level than you and me. She was like a fish deciding to climb up on land. And she tried that out for the length of time it takes to write one blog post, then took a deep breath, decided, meh, I'm going to stay in the water. It's easier. And she jumped back in the ocean with the rest of us dummies.

David Kestenbaum

Well, today on our show, we do not run from that fact. For once, we admit it. We embrace it, try to do something about it. We have stories today of people doing the hard work to confront the things they think they know, try to figure out how they know them and if they're actually true, and persevering-- not giving up until they get to the very bottom-- including a story about a question that brought our staff meeting to a complete halt the other week-- do women who live together actually get their periods at the same time? Is that real? What's the evidence? Oh, and a story about whether the earth secretly shifted on its axis without you and me and the rest of the world noticing.

From WBEZ Chicago, it's This American Life. Stay with us.

David Kestenbaum

Act One, Fraud Complex. When I was just starting out as a young reporter, I had this kind of mini crisis about how much I really knew and how I knew what I knew. I was covering a Congressional hearing where the head of NASA was testifying. It was this guy, Sean O'Keefe. This was just after the Columbia space shuttle accident.

And when I was reporting on it, I said this one sentence on the radio, nothing to do with the accident. I said that when O'Keefe had walked in, he was carrying a cup of coffee. But after, when the story aired, I was listening to my voice come out of the radio, and I kept thinking, was it really a cup of coffee? I don't know it was coffee-- could have been tea, or hot water, or room-temperature tang.

I told this to a veteran reporter who said, basically, relax. If you see two cows on a hill, you can say there are two cows on a hill, because, you know, how deep are you going to go? I've always wished I hadn't said it, though.

I was thinking about that because of one line I've been reading in news stories a lot recently about voter fraud. You can almost feel the reporters digging through the thesaurus, they've written it so often. Quote, "Academic studies show instances of voter fraud are very rare," or "Nationwide studies have consistently shown that voter fraud is almost non-existent." Another used the word, "minuscule."

But I wanted to know in a deeper way for myself, so I looked up some of those studies. And I have to say, I did not find what I expected. I thought there would be some kind of nationwide government audit, that there would be official reports from the election authorities in all the states detailing how they had looked for fraud. But there isn't anything like that.

In fact, most of the independent studies that have been done are just attempts to count up alleged cases of voter fraud. They look at court records, or news reports, and anecdotal accounts. And they never find much, which is good to know, but it didn't feel like proof. Maybe we aren't looking in the right way, or maybe voter fraud is hard to find.

I did find this one paper that seemed different from all the others. It was an attempt to do this big, ambitious thing. It was the only study I saw that actually dug into the voter data nationwide, all the votes cast in the United States, looking for one specific kind of voter fraud to try to see in a comprehensive way, did this kind of fraud happen? The specific type of voter fraud the study looks for is called double voting, where someone votes twice.

The Vice Chair of the President's Commission to Investigate Voter Fraud, Kris Kobach, has called double voting a big problem. He said people double vote all the time. This paper is 72 pages long. I printed it out, read it several times, and I called up one of the authors.

His name is Sharad Goel. He's an assistant professor at Stanford. Does social science work but, also has a PhD in math, and sometimes talks like it. I had him walk me through what they did.

David Kestenbaum

When you look at the voting data, he says there is definitely stuff where the numbers do seem funny. Like, every election, there are a lot of cases where it looks like someone might have voted twice-- cases where you have records of two votes cast by someone with the same name and birthday, which is weird.

Kris Kobach, President Trump's voter fraud guy, actually set up a program called Crosscheck that highlights these cases. States that want to participate send in their data, and Crosscheck looks for matches. It finds lots.

David Kestenbaum

Sharad and four other researchers wanted to check this out for themselves, so they got a hold of an enormous database that had the voting records gathered from all the states. They started this a couple of years ago, so they used the most recent presidential election at the time, which was 2012. And they looked, how many times in the whole country did you have two votes cast where both votes have the same first name, and last name, and birthday-- day, month, and year-- attached to them?

David Kestenbaum

They looked closer and realized that, first off, a lot of these were just problems with the data. Like, some states, when they didn't have a birthday, had put in January 1. So it looked like those people shared a birthday, but they didn't.

And there were other errors, where you had, say, a John Senior and a John Junior living in the same house, and they somehow showed up as having the same birthday. Sharad says they threw out a handful of states where the data seemed to be a problem. And the number of matches did go down, but not all the way down-- from 3 million to 750,000.

David Kestenbaum

Now comes the math. And I think this is where ordinary people would stop. But my friend, sometimes, when you want to get to the bottom of things, when you want to know, are people voting twice? How secure is the foundation of our democracy? When you want to know that, you have to do a little discrete probability calculation.

Specifically, you have to know about something called the birthday paradox. I first heard about it years ago. I was at a dinner party, and someone told me this thing, which is that, if you have just 23 people in the room, there's a 50/50 chance that two of them share a birthday.

I was in grad school at the time, studying physics, and I was like, that seems crazy. Just 23 people, two are going to share a birthday? Come on. There are 365 days in a year.

I left the table in the middle of dinner and went into this other room, shut the door, and tried to work it out on a piece of paper. I couldn't. Neither could Sharad, at first. He got assigned the problem in college.

David Kestenbaum

Turns out, there was an easy way to work out the birthday thing and a hard way. I had been stupidly trying to do it the hard way.

David Kestenbaum

It's this classic example of how what you think is right can just be so wrong when you do the math. And also, it might be the key to why it looks like so many people are voting twice.

A simple way to think about the birthday paradox and why it's right that, if you get 23 people in a room, the odds are about 50/50 that two of them will share a birthday is just to think about picking two people in that room. Sure, the odds are small that those two share a birthday. But in a room full of 23 people, it turns out there are a lot of possible pairs. Person one might have the same birthday as person two, or person three, or person four, or person two might share a birthday with person three, or person seven with person nine, et cetera. If you add it all up, it is way more common than you might think to get two people with the same birthday.

So Sharad and the other researchers did the math-- not for a room full of 23 people, but for a nation with over 100 million voters. And remember how they had 750,000 instances where you had two votes with the same name and birthday? The birthday paradox explains 720,000 of them. That's how many should share a birthday just by chance.

This weird math thing explains most of the instances where it looks like someone voted twice-- most, but not all. They still had about 30,000 cases unexplained, which would be a lot of fraud-- not enough to sway most presidential elections, but still, way more than he expected. Sharad says, at this point, he thought that was the real number. It would mean something like one in every 4,000 voters had voted twice, which seemed like, who knows? Maybe.

When they started out, Sharad says, they figured this whole thing would take a couple of days. But the bottom is often deeper than you think. The beautiful math I just told you about-- turns out it is not quite right, for a reason that is both subtle and very human. It gets messed up by parents doing stuff like this.

David Kestenbaum

And that, of course, means that the odds of two people named June sharing a birthday are higher than usual. The paper has a whole appendix just dealing with how to correct the calculation for our peculiar naming habits. It's 12 pages of equations and theorems.

It's not just that babies born in June, the parents sometimes name them June. Girls named Autumn tend to be born in the fall. Also, babies in general are more likely to be born during the week than on weekends. Sharad says they knew this stuff might be an issue, but when they looked through the voter data, it was a bigger complication than they thought.

Another example-- Josefina with an F, 1 in 10 chance you were born on March 19. I thought I'd figured that one out. There's an American Girl doll named Josefina with that exact birthday. Sharad doesn't think that's what inspired people, though. March 19 is also St. Joseph's Day.

In any case, all this was a problem. So Sharad and the other researchers redid all the calculations to account for the fact that if two people have one of these particular first names, they're more likely to share a birthday. And it did reduce the number of possible fraudulent double votes from 30,000 to 20,000.

David Kestenbaum

They could have published their work and this number, 20,000 possibly fraudulent double votes. But there was one other thing to consider. They started wondering if there might be errors in the data. Like, maybe the data file says someone voted, but that's wrong. The person didn't vote, in which case, what looked like a double vote might actually just be a single vote. Maybe that would account for some of the 20,000 double votes.

But to check this, after doing all that fancy math, they had to go out into the messy world. The researchers sent out a team of undergrads to go through some poll books in Philadelphia. I talked to one of the students who did this. He said the books were in this forgotten building in a run-down part of town-- three-ring binders with the names of registered voters. On election day at your polling place, you find your name and sign next to it in the book.

It was super boring work, he said. They double-checked 11,000 names-- people the data file listed as having voted. And they found, in about 1% of the cases, according to the poll book, the data file seemed to be wrong. There was no signature. It didn't look like the person had actually voted.

David Kestenbaum

Sharad is not saying there is zero double voting going on-- just that it seems like a really small problem. And to be clear, voting twice is just one way people can commit voter fraud. There are others-- non-citizens voting, dead people voting, vote buying, corrupt officials just changing the tallies, though there is no evidence any of those is happening in any substantial way either.

Sharad says they finished up their research just days before the 2016 election, which was pretty good timing. The issue of voter fraud was in the news. After Trump won, he started going around saying that he would have won the popular vote, too, if you deduct the millions of people who voted illegally. And once he was in office, he set up his Commission on Voter Integrity that would collect data from the states and look for fraud.

Sharad says, in all of this, there is one number he's come across that he just does not understand. There was this survey done before the election in which half of all registered voters said they thought voter fraud was very common or somewhat common-- 61% of Republicans and 30% of Democrats.

David Kestenbaum

Sharad says their paper did not get a lot of attention-- mostly just a line or two in some news stories.

David Kestenbaum

Sharad meant this in a technical way. Like, the paper is still being peer reviewed, they don't know if the error rate they found in the Philadelphia voter data can be applied to the whole country, stuff like that. I meant it differently.

Sure, we'd talked for hours. I'd read the paper a bunch of times, but I didn't actually check the math. Honestly, I don't understand all the equations. And I didn't go over their computer code or look at the data sets. I believe what they found, but I don't know it.

It looks like a cup of coffee, so I'm going to say it's a cup of coffee. And later today, I will get in my car whose engine is a mystery to me. I will drive on roads built with a tax system I only roughly comprehend, and I'll pick up my two little kids from school. They are full of questions these days. I always pretend to know more than I do.

David Kestenbaum

Act Two, Flake News. Sometimes there's a thing that you think you know, even though, right in front of you, staring you in the face, is clear evidence to the contrary. That happened this week to one of our producers, Zoe Chace. In her case, the thing staring her in the face was a US senator. Here's Zoe.

Zoe Chace

I've spent the last few months following Senator Jeff Flake from Arizona. We talk every other week, pretty much. I tag along with him to committee meetings and speeches in the Capitol. The plan was, I was going to follow him all the way through his re-election campaign next year. And then this week, as you might have heard, Flake announced he's not running after all. He gave a pretty emotional speech on the Senate floor about it.

Zoe Chace

I was shocked. I did not see this coming. Now, people are talking about this speech as a turning point for the Republican Party-- one more old-school conservative realizing he can't win in the age of Trump. Like every reporter in Washington, I ran after Flake when his speech ended.

Zoe Chace

We did talk last week. We had had this unusual moment. But at the time, it didn't seem like a big deal. Knowing what I know this week, I hear it differently.

It was last Thursday, a beautiful day in DC. It was vote-a-rama in the Senate. Vote-a-rama is this weird Senate procedure where senators have to vote on a different proposal, like, every 20 minutes or so in order to ram the budget through.

I was waiting for the senator, like I often do, right outside the Senate gallery. He came out, but instead of getting on the elevator to go back to his office, he goes, let's go out here. And he takes me through this door only senators are supposed to use, to a place reporters aren't allowed to go-- onto the Capitol steps.

He tells the guard, she's with me, and we're out.

Nice out here, he says. Sunny. We sit down next to each other on the world's biggest stoop, gazing out at the Capitol Grounds and the Supreme Court. And then suddenly, it's like he's looking back on his 18 years in Congress.

Zoe Chace

The Gang of Eight was this bipartisan group of senators who worked together on immigration reform. They wrote a big bill, which didn't pass, but Jeff Flake's really proud of that time. I asked him if he was feeling nostalgic. And for some reason, he started talking about 9/11.

Zoe Chace

For the life of me, I couldn't figure out why we were talking about 9/11. And it was only after I heard his speech this week that I realized what it was about. He was nostalgic for Congress working the way it used to-- Republicans and Democrats wanting to work together to make a thing happen. 9/11 was the biggest example of that that Jeff Flake could think of at that moment.

Zoe Chace

I knew that Flake wasn't sure he'd win the next election. But now I see he was coming to terms with the decision he was about to make.

Talking to Flake that day was like talking to a friend who knows his relationship is over,

but can't quite say it. He was coming to grips with a breakup.

Zoe Chace

I should have known what he was about to do.

David Kestenbaum

Zoe Chace with Senator Jeff Flake of Arizona, who bowed out of the Senate this week.

David Kestenbaum

Coming up, the sun, kind of. That's in a minute, from Chicago Public Radio, when our program continues.

It's This American Life. I'm David Kestenbaum. Ira Glass is out this week. Today on our show, "Things I Mean to Know," stories of people questioning some basic things in their lives and the world that they have always taken on faith.

David Kestenbaum

Act Three, The Sun Also Rises Over There. So among the things I accept as true is the fact that the world is round. But I have to say, there is not a lot to remind you of that in day-to-day life. Like, the ground does feel flat.

If you happen to live up in the Arctic, though, you are sometimes reminded that we live on this ball that is spinning through space. Our next story is about a researcher named Ian Mauro who went there-- way up on top of the earth where people still hunt seals and walruses. He was helping make a documentary, interviewing people about climate change. He figured they'd probably seen all kinds of stuff we never hear about, and he was right. Selena Ross tells the story.

Selena Ross

When Ian asked people about climate change, he heard a lot of the stuff you'd think you'd hear-- glaciers are melting, and one year, it got super hot for a couple of weeks-- like, LA hot. You could wear shorts and no shirt.

But then Ian heard this other thing that really took him aback. He couldn't get it out of his head for months. He was going around from one remote village to another, assisting a well-known local Inuit filmmaker named Zacharias Kunuk. And that weird thing, they heard it over and over again.

The person who laid it out most dramatically was an elder named Augustine Taqquraq. They were in Igloolik, a small town way up in northern Canada, above the Arctic Circle, in this little office with a window that faced a sandy beach.

Selena Ross

In other words, the sun was coming up in the wrong spot. When Ian heard that, he really took notice. The sunrise Augustine was talking about wasn't just any sunrise. He was talking about the year's first sunrise after the polar night, that it was happening at a different place on the horizon than usual. This is the kind of thing people pay close attention to in the Arctic-- the first ray of sunshine after months of 24-hour dusk and darkness.

Selena Ross

Augustine and the other elders Ian talked to had an explanation for why this might be happening, but it also sounded kind of impossible. Here's a clip from Ian and Zach's film. This is a man named Inookie Adamie, who had also seen the sun in the wrong place.

Selena Ross

He says, I don't know everything, but I've lived here all my life, and I've also watched the sun. Perhaps the earth has tilted on its axis. A bunch of people said this to Ian and Zach. They thought the earth had changed its tilt.

Selena Ross

Ian believed the Inuit. He believed the elder, Augustine, was seeing the sun come up in a place it never had before. But how? He started calling around to different scientists-- like, cold-calling people who studied anything to do with the earth spinning. He was asking them, is it possible the earth is tilting? That the sun had moved in the sky?

Selena Ross

For the tilt of the earth to change that much, scientists told me, an asteroid would probably have to collide with it. Like, we'd have noticed. The very idea that the earth's axis might have undergone some massive shift actually annoyed a lot of scientists. And the fact that Ian took it seriously really annoyed them.

Scientists tended to think it was a figment of people's imaginations or a mistake. After Ian went on TV talking about the sun coming up in the wrong spot, he remembers getting a letter from an official Astronomical Society. Actually, they sent it not to him directly, but to his boss at the time, at the university where he was a new professor.

Selena Ross

People told Ian he was fueling conspiracy theories and that he was ruining his own credibility and his career by focusing too much on this. But Ian kept at it. And he got a tip. He and Zach were out doing more filming.

Selena Ross

Waldemar didn't think the earth had tilted on its axis.

Selena Ross

But he didn't hang up, because he did believe that the Inuit we're seeing what they said they were seeing, and he thought he knew why.

Selena Ross

In 1597, a bunch of Dutch explorers had been shipwrecked on the island, and they had also seen some weird stuff with the sun. They had to wait out the Arctic winter before they could try to get out. They were counting down the days-- like, if we can just make it till the sun comes back, we'll be OK.

The captain knew some astronomy and did some calculations-- the sun should be back on February 8. They circled that day in their calendars-- February 8, Sunrise Day. But then--

Selena Ross

It was a full two weeks early.

Selena Ross

Then, a few days later, he saw it too. And not just a glimmer of the sun, but, quote, "its full roundness, just free of the horizon."

One of the sailors wrote a book about the voyage when he got home. That started a big controversy in the scientific world. And it was 200 years before people got to the bottom of it. The answer-- it was a mirage, a huge one where you see the entire sun, even though it should be hidden over the horizon, out of view.

For this weird thing to happen with the sun, for you to be able to see it even when it should be out of sight, the weather conditions have to be just right. You need a very cold layer of air on the surface and warm air above. If you get that, the boundary between the two acts like a mirror. The sun gets reflected in the atmosphere, kind of bounced around the curve of the earth, and the result is, you can see the sun even days before it technically rises.

And this, it turns out, could explain what was happening with the Inuit. Maybe the sun didn't actually move, but it looked like it did. Or rather, they were getting a sneak peek before it returned from the long polar night. And therefore, it really was in a different spot on the horizon.

To test whether it was, in fact, the Novaya Zemlya effect, Waldemar needed some data. Around that time, Ian and Zach were in Igloolik to film the return of the sun after the polar night. Everything was covered in ice and snow. People were hanging out, burning oil lamps, and eating caribou. In Igloolik, it's a big celebration waiting for the sun. It's fun-- very cold, but fun.

Selena Ross

It did return, and they caught it on camera.

Selena Ross

That's what always happens on the first day. It's super short. Ian took the time stamps of his video and told them to Waldemar, who just looked up that time and date in the astronomical charts to find out where the sun actually was then. And he confirmed what Ian and the others on the beach had seen was a mirage. Even though they saw the sun, it wasn't really there that day. It was below the horizon, still-- far below the horizon.

As for why it's happening, like, now, we talked to a bunch of climate scientists and asked if global warming could create the Novaya Zemlya effect more often-- make cold and warm air collide more frequently in a way that turns the atmosphere into a giant mirror and produces the reflection. Some said yes, some thought no. Waldemar, the scientist, likes the climate change explanation.

Selena Ross

It turns out, because of those same atmospheric conditions, the Inuit see crazy things all the time, things none of us in the south ever see-- land floating above land like a flying saucer, or mountain ranges where there's actually only ocean. The Inuit have a name for these mirages, [NON-ENGLISH] And hunters can read them.

One man told me he's seen what appears to be a towering, skinny polar bear. And he knows from how it looks that it really is a polar bear, it's just over the horizon, where it should be out of sight. And if he heads towards it, he'll find a real animal there. So the sun rising in the wrong spot? It's just one more thing.

David Kestenbaum

Selena Ross. She's a reporter in Montreal.

David Kestenbaum

Act four, Period Drama. So a couple of weeks ago, when we were having our story meeting for the show, Diane mentioned this thing. She said a friend of hers had told her that there's basically no good scientific evidence for menstrual syncing. This is this idea that when a bunch of women spend time together, their periods tend to sync up. And when she said that, every woman in the room was like, what? Of course, that's true.

This was not something that was on Diane's list of seven things she needed to know, but all of a sudden, it was on everyone else's list. So we sent her off to find the answers. Is it really not true? And if it isn't true, why does everyone still believe it's true? Here's Diane.

Diane Wu

When I mentioned this to my coworkers, a lot of them had stories about how period syncing had happened to them. Someone said, but wait, my whole swim team was synced up in high school, or the girls in my friends' dorms made t-shirts that said, we cycle together. To many women, it's a natural fact, and it's hard to believe otherwise.

Just a few weeks ago, I went to a dorm room and talked to two roommates-- Rebecca and Saskia. They're juniors. They live in a double on the first floor. It has bunk beds, a giant thrift store rug, little plants, and a birdcage decorating the windows.

Diane Wu

They're best friends. Freshman year, when they both had singles, Saskia would sleep over in Rebecca's room most nights. They're always together.

Diane Wu

Are your periods usually synced?

Diane Wu

I asked them if they'd heard of any scientific explanations for period syncing.

Diane Wu

Before I tell you why period syncing might not be real, I have to tell you why it was real in the first place. The story of how it became so popular also starts in a college dorm-- at Wellesley College, back in the late '60s. There was a student, Martha McClintock, who had this chore in her shared bathroom.

Diane Wu

Period syncing wasn't the familiar idea it is today. Women might have noticed their periods overlapping, but it wasn't a whole phenomenon that everybody knew about. It didn't have an official name. So Martha didn't attach any significance to her observation. It was just a little note she'd made about the world-- that a lot of woman living in her dorm had their periods at the same time.

She was studying biology and spent a summer doing research at a laboratory in Maine. The researchers would hold these lunchtime talks. Martha would usually be the only woman in the room, and she sat with the other undergrads in the back. During one of these lunches, some scientists were talking about how groups of female mice could affect one another's ovulation. It reminded Martha of the pattern she'd seen with how her suite mates used up all the Tampax at the same time.

Diane Wu

Martha collected the data from the women in her dorm. She asked about the start dates of everyone's periods between October and March. Then she looked at three groups of women-- roommates, closest friends-- these were women who listed each other as closest friends, the sad cases where only one woman thought they were closest friends didn't count for the study-- and random pairs.

What Martha found was this. The random pairs didn't change significantly over the school year, but the closest friends and roommates, their periods got closer together. In October, when they'd only been at school together a little while, their periods started around nine days apart. By March, the difference had dropped to around five days.

Diane Wu

Menstrual synchrony-- it was the first time the idea had been given a scientific name. She published her results in the journal Nature in 1971, this study of 135 women in a dorm, and it was an instant sensation. Martha's work was exciting to scientists because it suggested that just hanging out with another person could change your body's clockwork. It had been recently discovered that insects and mice could send chemical signals to each other through the air, these things called pheromones. And Martha's paper opened up the possibility that maybe we, too, were sending messages in this secret new dimension.

Diane Wu

Other scientists began conducting their own period syncing studies. Among lesbians, and sisters, and coworkers, and teammates, and rats, and tamarinds, and hamsters, and chimps, scientists, including Martha, tried to figure out how these pheromones were getting from one person to another by putting cotton balls under one woman's armpit then under another woman's nose.

And at the same time menstrual synchrony was gaining traction in science, it was filtering into the culture. Period syncing started coming up in movies, magazines, TV. Here's a scene from the show Married with Children.

Diane Wu

It's from an episode where all the women on a camping trip sync up, attracting bears and ruining it for the guys. There's a lot of that kind of stuff-- male characters who think they're really hilarious making jokes about periods.

The dad in My Wife and Kids calls it DEFCON 2 when his wife and daughters sync up. A scene in the rom-com No Strings Attached where Ashton Kutcher brings cupcakes to an apartment full of menstruating women. There's an episode of Charmed where the witches sync up, and it messes with their magic. In Sex and the City, Samantha thinks she might be starting menopause because she's out of sync with her friends. And then there's Dwight Schrute on The Office, peering into a conference room full of women.

Diane Wu

By the '90s, Martha had become a tenured professor at the University of Chicago, running a lab that studied how behavior and environment affect reproduction. And everything was going great until a paper came out that challenged the existence of period syncing.

Diane Wu

That's Jeff Schank. He was a post-doc in Martha's lab when that paper was published in 1992. It was by an anthropologist named Clyde Wilson. Martha had Jeff look through it to see if they could write a rebuttal together. Jeff thought it would be easy to find errors.

Diane Wu

The argument Jeff found the most persuasive was that a woman's period isn't the same length every month-- it might be 30 days one month, 24 days the next. And because of that, when you compare two women's periods, it might look like they're starting to get closer together, but it's really just chance. To account for this random thinking, you'd need either a really large sample of women or to run your experiment over a long time. Martha's paper didn't have either of these.

There were other problems, too. Jeff was convinced by Wilson's arguments, and that made him uncomfortable. He had spent almost six years on work he was now learning had rested on a faulty assumption. He started to worry--

Diane Wu

He told Martha that he couldn't help her write a rebuttal, that Clyde Wilson had actually gotten it right.

Diane Wu

Jeff went on to publish a bunch of papers debunking other synchrony studies, showing one by one that their results could all be explained by chance.

Diane Wu

I asked Martha about all this. And despite all the evidence to the contrary, she still maintains that menstrual synchrony does exist.

Diane Wu

The answer to that question may be never, but Martha stands by her original study. I went back and forth with her, trying to understand her arguments. Her main one is that maybe syncing can only be measured in just the right conditions. But nobody's identified what these conditions mighg be-- not Martha, not any of the later researchers.

I brought a copy of one of Jeff's papers to show Rebecca and Saskia back in their wood-nymphy dorm room.

Diane Wu

Rebecca read the abstract with her eyebrows furrowed. She'd wanted menstrual synchrony to be real.

Diane Wu

I hate to be that asshole saying period syncing is scientifically inaccurate, but here I am. There isn't any good evidence for period syncing. Everyone in this story wanted it to be true, even Jeff, the guy who worked on disproving it, which is a feeling I understand.

When I was a chemist, I was always surprised by how much wishing I did in the lab. I spent weeks trying to cook up these little nanoparticles that hardly ever came out the way I needed them to. And every time I went to check my latest batch, in that moment just before I looked in the microscope, just before I found out if I'd finally gotten them right-- that was probably the closest I've ever come to praying. It's the exact opposite of how I thought science was supposed to work.

David Kestenbaum

Diane Wu is one of the producers of our program.

Our show was produced today by Dana Chivvis. Our staff includes Elna Baker, Susan Burton, Zoe Chace, Sean Cole, Whitney Dangerfield, Neil Drumming, Stephanie Foo, Chana Joffe-Walt, BA Parker, Robyn Semien, Christopher Swetala, Matt Tierney, Julie Whitaker, and Diane Wu. Our senior producer is Brian Reed. Music help from Damien Graef.

[ACKNOWLEDGEMENTS]

Our website, ThisAmericanLife.org. This American Life is delivered to public radio stations by PRX, the Public Radio Exchange. Thanks to our boss, Ira Glass. He told me, when you're hosting the show, it's really just one thing you've got to remember.

David Kestenbaum

I'm David Kestenbaum. Join us next week for more stories of This American Life.