Do Women Earn More During Their Fertile Window? (Episode 548)

Full Transcript: Episode 548

Lisa Hendrickson-Jack:

In today’s episode, I am diving into a really interesting and slightly controversial study. It’s a study that I mentioned in The Fifth Vital Sign in the pill chapter — so chapter seven — and it is often referred to just as the stripper study. I was doing a podcast interview on a different podcast last week, and the host was asking me a whole slew of really interesting questions. And we ended up talking briefly about hormonal contraceptives, and I mentioned the stripper study, and she had never heard of it. And so it made me think, you know, this would be a really great FAMM Research Series to dive into, because many of you may not have heard of the study either. And I thought this would also be a great follow-up to last week’s episode. In last week’s episode, we touched on this concept of genetic compatibility and how hormonal contraceptives may disrupt our natural tendencies in terms of how we would be selecting partners. So we’re going to go ahead and jump into today’s study. It is called Ovulatory Cycle Effects on Tip Earnings by Lap Dancers. And so we’re going to get into this study and talk about what it suggests, what we can learn from this really interesting and very unique study.

So when I brought this up in the podcast interview that I mentioned, one of the first questions that my interviewer had for me was like, “Who did this study? What’s going on?” So I don’t have all the specifics, but I will share some of the information so that you can get a sense of what the researchers were thinking about. So the researchers start the study by explaining their rationale for wanting to do this. And they essentially start by talking about the concept of estrus, or the estrus cycle. And this is often how the fertility window is talked about in animals. So if we’re looking at cows, there are a number of research studies on cows and estrus that I did actually bring into The Fifth Vital Sign, and that’s how they talk about it. So the kind of idea of when you have a cat in heat, or something like that, or a dog in heat — it’s referred to as that estrus phase.

These researchers are posing the question: is the human estrus cycle — so to speak, that concept of being in heat — the time obviously around your ovulatory window — do we have any signs of this that maybe are not at the conscious level? Are there cues that would attract males to females in this phase? So they’re essentially asking that question. If I read a little excerpt from the study, they say, “However, the conventional wisdom holds that the human female estrus became uniquely lost or hidden over evolutionary time.” So they’re saying that the prevailing idea was that human beings no longer have that kind of estrus cycle — that it was lost at some point. And their hypothesis is that, no, we actually think that human beings still do have an estrus cycle, although it might not be as obvious as if a dog is in heat or whatever, but that’s their hypothesis. And they were thinking of ways to test this theory. And so they came up with this study to actually test to see if women who are lap dancers would have a change or difference in their income, depending on whether they were cycling or not, and also depending on where they were in the cycle.

So I’m going to go ahead and talk a little bit about how they organized this. They share a little bit about their study design — they recruited potential candidates, but they didn’t provide them with the full explanation of what they were looking for. If I take from the study, they say: to minimize possible response bias, we mentioned the ovulatory cycle only in the recruitment and consent, and we did not suggest that tip earnings would be examined specifically as a function of days since the menstrual onset. So they shared enough that the participants would know they were looking at their cycle, but they didn’t tell them specifically that they wanted to see if the earnings would be different around ovulation compared to around their period or anything like that.

They ended up recruiting 18 dancers who recorded their menstrual periods, their work shifts, and their tip earnings for about two months. They would daily jump on to the computer and input the data — they had a survey that they would fill in on a day-to-day basis. They were asking about their cycle, when their period started, what was going on. And although imperfect, they would use the period data in a bit more of a general sense: if their period starts on this day and the next one started on this day, then they would make a fair estimate of when they were likely in that ovulatory cycle.

Of course, being me and having my fertility awareness educator background, you could nitpick at that and say, “Oh, well, they weren’t specifically testing LH levels, or they weren’t specifically confirming ovulation with temperature.” For what it’s worth, I mean, they still get a general sense potentially of when that ovulatory cycle is. So I think it’s still valid, although it could have been a little bit more specific in terms of how they were identifying that ovulatory window.

One other interesting part of the study was that there were some of the participants who were on hormonal contraceptives, and then there obviously were some that were not. So they actually compared those who were cycling naturally versus those who had no hormonal variation in the sense that they were always on the pill — so there wouldn’t have been any change hormonally around that estrus period, if you will.

In the words of the researchers, they say that they are presenting the first real-world economic evidence of male sensitivity to cyclic changes in female attractiveness. They went into some detail about the environment — I found this to be really interesting. Of course, it’s super controversial, and I’m sure some of you are thinking, who thought of this? So they went into a little bit of specifics about the environment of the strip club. They chose a specific strip club in Albuquerque over a specific time period. They painted a picture of the environment: the clubs serve alcohol, they’re fairly dark, smoky, loud. They specify that the dancers are topless but not bottomless by law, and then they explain how the dancers make their money. The bulk of the money is made by lap dances. They explain what that looks like, and they explain the line between a lap dance and where it would become illegal if it crossed into prostitution.

Basically what they’re saying is that since the bulk of the money is made in that very close contact environment, theoretically this would provide a situation where two people would be in very close contact. And if there was a difference in pheromones, olfactory scents, or any of these things — if you think back to the previous episode where I talked a little bit about the t-shirt studies and the research showing that women generally have a preference for the scent of men who have more dissimilar genes — they’re kind of going along with that idea. Their hypothesis is that when women are in their fertile window — or estrus, to use their language — men would be potentially more likely to be attracted to them. The lap dance environment would provide this opportunity to test to see if there’s any difference when women are in that ovulatory phase versus when they’re not.

So let’s talk now about the results — what actually happened. I mean, this doesn’t really surprise me because I’ve been in the field so long. They did find that the women who were naturally cycling on average made more money than the women who were on contraceptives and didn’t have any change because they didn’t have that ovulatory window. If we look at it specifically in terms of dollar amounts, the overall participants were earning about $248 US per shift. But when they looked at the normally cycling women, they found that they made much more money during their ovulatory window — during their estrus phase, they averaged about $354 per shift — about $90 more than during the luteal phase, and about $170 more than what they earned during the menstrual phase. When they looked at the women who were cycling normally, they had a huge uptick in their per-shift earnings when they were in their ovulatory window, and then they made the least money when they were actually during their menstrual phase, when they were on their periods.

They actually broke the earnings down into what they earned hourly. The estrus women — so the women in their fertile windows — made about $70 US per hour, versus the women when they were in their luteal phase, who made about $50 US per hour. And then when they were menstruating, they made about $35 US per hour. So they were essentially doubling their earnings per hour during their estrus phase. When they contrasted this to the pill users, the pill users didn’t have a mid-cycle uptick in their earnings — they just earned a steady amount per shift. On average, the pill users made about $193 US per shift compared to the normally cycling women who on average made about $276 per shift. That was a loss of more than $80 per shift. The women who were cycling normally — even though they had an uptick around ovulation and a dip during their periods and a dip also during their luteal phase — on average made $80 per shift more than the women who were not cycling and were on hormonal contraceptives.

Now, of course, there are some limitations of the study. This is a very small population size. I think a lot of people may not take it seriously given that it’s a bit controversial and that they used this kind of environment to make a point. At the end of the day, it’s a very interesting conversation piece and a very interesting study to bring up and to talk about. I think what we can learn from it is that, at least based on what they found, there is a change in how men perceive women during their fertile window.

And of course, this type of research is very gendered. When we get into this concept of selection based on genetics and all of this kind of pheromone stuff, this study is a bit unique given the nature of the study. There are other studies and other research that points to similar types of things — there’s research showing that men prefer the sound of women’s voices more during the fertile window. There’s a variety of different studies that have hinted at this or specifically looked at the question: is there a change in how men perceive women’s attractiveness during their fertile window compared to outside of their fertile window?

The researchers cited a few different studies. There was one study where several women were photographed at different times of their cycle. These women were just told to get dressed and get ready, and they took the picture — so they were choosing their own outfits and putting themselves together at the different times of their cycle. They found that there was a pretty strong percentage of men who would choose the photos of the women who were during their ovulatory phase. So there are a variety of other studies that do look at this question in different ways, and although this study is unique, there is other research to suggest that there is something to this concept — that men do find women potentially more attractive when they’re in that fertile window versus otherwise — and that can be due to a whole variety of hormonal shifts and changes that are happening during that time.

And anecdotally, after working with so many women and having that work center around the menstrual cycle — many of my clients are trying to conceive, or many of my clients are trying to avoid, but either way we’re tracking the cycle and we’re looking at what’s happening during that time — many women do find that maybe they feel more attracted to their partners at that time, or maybe their partners are feeling more attracted to them around that time. So in an anecdotal sense, I have seen those types of shifts happen just based on where women are in the cycle.

I think what we can learn from this study is just that there is something to that idea — not to say we’re ruled by our cycles, because it’s not the whole explanation — but that there is maybe a tendency during that time to have just a greater push, if you will. The researchers did make some suggestions for potential future research. If anyone wanted to pursue this further, they could potentially look at larger sample sizes, they could identify ovulation more precisely using the luteinizing hormone surge or using urinary metabolites so that it could be more specific in terms of identifying that ovulatory window. There are probably other creative ways to measure these ideas without necessarily going the lap dancing route.

But nevertheless, it’s a study that I wanted to share, especially for those of you who hadn’t heard it before — just to build on what we talked about last week, related to this concept that our bodies, in one way or another, whether it’s our olfactory senses or whether it’s our cervical mucus, may somehow be screening for genetic suitability. Which is really wild if you think about it, because all these things are typically happening below our subconscious awareness. It’s something that our bodies were designed to do, but we don’t necessarily have control over, nor do we actively realize that it’s happening.

So if you want to take a peek at the research around this question, you can head over to fertilityfriday.com/548. We’ll put all the links in there. If you’re loving the FAMM Research Series and you’re wanting to dive into previous episodes that we’ve released in our research series, head over to fertilityfriday.com/research. So with that said, I hope you have a wonderful week. Until next time, be well and happy charting.