# Menstruation and the Moon **URL:** \ **Category:** Factual Questions\ **Created:** [February 17, 2006, 10:23pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021 "2006-02-17T22:23:02Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Youbetcha](https://avatars.discourse-cdn.com/v4/letter/y/b19c9b/32.png) [@Youbetcha](https://boards.straightdope.com/u/Youbetcha)\ **Post date:** [February 24, 2006, 6:36am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/41 "2006-02-24T06:36:03Z")
Interesting article CookingWithGas but I will have to disagree with you and Cecil on this one. Yes there have been some old studies that suggest synchronicity exists but with no reasons why and some pretty shaky experimentation to begin with. Mostly anecdotal. The 7 lifeguards? That’s funny. I’ll stick with my wife’s two year experiment and other more recent articles I’ve seen that suggest otherwise. In fact the seven women in our experiment had cycles over the two years varied a bit in duration and length of period (for non pill users) but never stayed synched up in any way, though for brief durations some of them synched. Just a coincidence of their varying lengths though. If anything the two that were similar in time and length to begin with grew apart because they weren’t exact. All of the women said that from the start (or after the first few years) their periods were of X number of days and rarely were off by more than two days + or -. In fact they were so regular that each individual had a story about the time it was 4 or more days late and they were afraid they were pregnant. There were some drastic abrupt changes in the group during their lives but nothing we could put down to synching up with moms , sisters or roommates. It certainly wasn’t 135 women as in the other study, and by no means conclusive, but because of it I would not take the other studies conclusions as fact in any way. I think both of us have too small a sample with too many variables. I would agree however that this is unfortunately common knowledge with most women. But then again so is the moon cycle phenomenon which I think has been fairly conclusively proved to be false here. I think it comes down to women needing something mystical to bond around that males can’t be part of or ‘understand’. If they only knew we understand very little to begin with. 🙂 ---
**Author:** ![lorinada](https://avatars.discourse-cdn.com/v4/letter/l/b5e925/32.png) [@lorinada](https://boards.straightdope.com/u/lorinada)\ **Post date:** [February 24, 2006, 7:17am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/42 "2006-02-24T07:17:16Z")
Forty-one posts and not a one of them pounces on this little gem (bolding mine): > [@](#): > > **Without trying** and **without thinking about it** , my monthly menstrual cycle begins on the full moon nearly every month. Maybe, just maybe, if all us gals concentrated \*real hard \* and _tried our best_, we could menstruate just about whenever we wanted! :rolleyes: :wally ---
**Author:** ![outlierrn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/outlierrn/32/3005_2.png) [@outlierrn](https://boards.straightdope.com/u/outlierrn)\ **Post date:** [February 24, 2006, 7:55am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/43 "2006-02-24T07:55:23Z")
Ok, so wouldn’t evolution "want " women to ovulate as far apart from each other as possible? If all the women in a hunter gatherer group synchronized wouldn’t that reduce their overall fertility? Just a thought ---
**Author:** ![Maastricht](https://avatars.discourse-cdn.com/v4/letter/m/a88e57/32.png) [@Maastricht](https://boards.straightdope.com/u/Maastricht)\ **Post date:** [February 24, 2006, 8:42am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/44 "2006-02-24T08:42:32Z")
Apart from everything else, let’s not forget that a full moon is just the same old moon as the rest of the month. Why should it make any difference from which side the thing is illuminated? ---
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [February 24, 2006, 1:47pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/45 "2006-02-24T13:47:14Z")
> [@AskNott](#): > > The menstrual trash, collected daily, was always greatest in the week before a full moon, and scarce in other times. I’ve been watching from the sidelines as yet, but I wanted to throw in this nitpick you missed in the pro/con list. The only possibly notable thing here is that said trash followed a monthly cycle. That is, that the women tended to clump up (sorry) around that week. Where that week _happened_ to be in reference to the moon is still a coincidence, and you’ve presented no evidence at all that there was any connection between the phase of the moon and the heavy time of the month. ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [February 24, 2006, 2:26pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/46 "2006-02-24T14:26:33Z")
> [@lorinada](#): > > Forty-one posts and not a one of them pounces on this little gem (bolding mine): > > Maybe, just maybe, if all us gals concentrated \*real hard \* and _tried our best_, we could menstruate just about whenever we wanted! > > :rolleyes: :wally **lorinada**. In General Questions, we try to avoid using the “putz” smiley. Thanks. **samclem** GQ moderator ---
**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\ **Post date:** [February 24, 2006, 2:37pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/47 "2006-02-24T14:37:10Z")
> [@Cartooniverse](#): > > Look, maybe it’s just me, but I am thunderstruck. It is reasonable to expect that an animal with a **5 day estrus cycle** such as a rat should be a difficult animal to be around. No? Heh. At work at the lab, a mom mouse would often have a litter in the cage with her and then give birth again to another set of pups. “What a slut,” we’d say. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [February 24, 2006, 2:47pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/48 "2006-02-24T14:47:44Z")
> [@Mathochist](#): > > I’ve been watching from the sidelines as yet, but I wanted to throw in this nitpick you missed in the pro/con list. > > The only possibly notable thing here is that said trash followed a monthly cycle. That is, that the women tended to clump up (sorry) around that week. Where that week _happened_ to be in reference to the moon is still a coincidence, and you’ve presented no evidence at all that there was any connection between the phase of the moon and the heavy time of the month. In addition, this account is subject to the confirmation bias. When the greater quantity of trash happenes to coincide with a full moon it is remembered. These accounts are really of little value without a full, written record of what happened and when, made at the time. ---
**Author:** ![lorinada](https://avatars.discourse-cdn.com/v4/letter/l/b5e925/32.png) [@lorinada](https://boards.straightdope.com/u/lorinada)\ **Post date:** [February 25, 2006, 3:52am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/49 "2006-02-25T03:52:02Z")
> [@samclem](#): > > **lorinada**. In General Questions, we try to avoid using the “putz” smiley. Thanks. > > **samclem** GQ moderator My apologies. Since I browse from the “new posts” list I sometimes lose track of where I am. ---
**Author:** ![Cartooniverse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cartooniverse/32/3084_2.png) [@Cartooniverse](https://boards.straightdope.com/u/Cartooniverse)\ **Post date:** [February 27, 2006, 12:45am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/50 "2006-02-27T00:45:51Z")
> [@gigi](#): > > Heh. At work at the lab, a mom mouse would often have a litter in the cage with her and then give birth again to another set of pups. “What a slut,” we’d say. Now, now. No need to be judgemental. Around these parts, we’d have said, " How enthusiastic !!! " 😃 I think we may be overlooking a fairly important factotum, offered by our friend **Maastricht**. The lunar distance and lunar image are different things. The moon is rotating on an axis and rotating around the Earth, both. How much light we see in the sky is the result of course, of how things line up, cosmically speaking. 😉 I would think those trying to tie menstruation to tidal forces may be on to something in a way that those trying to tie menstruation to what phase of the moon is apparent to us are not. ---
**Author:** ![elelle](https://avatars.discourse-cdn.com/v4/letter/e/f0a364/32.png) [@elelle](https://boards.straightdope.com/u/elelle)\ **Post date:** [February 27, 2006, 3:33am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/51 "2006-02-27T03:33:11Z")
> [@outlierrn](#): > > Ok, so wouldn’t evolution "want " women to ovulate as far apart from each other as possible? If all the women in a hunter gatherer group synchronized wouldn’t that reduce their overall fertility? Just a thought I don’t see how it would reduce fertility, from a female standpoint. From a male view, it might mean you could always get a mating situation the whole month round, because someone would be available. In a tribal situation, though, synchronizing menses might have some advantage in a working female community sense; the whole group works when in physical prime, and then rests during menses. Kinda like our current concept of “weekends” but not spread throughout the month. Work three weeks, rest for one during duress. For hunter gatherers, mobile by necessity, this would be a good tactic, rather than have female members dragging along at various times. ---
**Author:** ![smartie](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@smartie](https://boards.straightdope.com/u/smartie)\ **Post date:** [March 2, 2006, 2:46pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/52 "2006-03-02T14:46:56Z")
> [@elelle](#): > > I don’t see how it would reduce fertility, from a female standpoint. From a male view, it might mean you could always get a mating situation the whole month round, because someone would be available. I have heard it explained that if all the women are fertile at once, the man can go out hunting for a few weeks, come back at the appropriate time, for a few days, and hatch a multi-mothered breed of offspring in one active weekend. And then back to the woolly mammoth chase. ---
**Author:** ![Maastricht](https://avatars.discourse-cdn.com/v4/letter/m/a88e57/32.png) [@Maastricht](https://boards.straightdope.com/u/Maastricht)\ **Post date:** [March 2, 2006, 3:07pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/53 "2006-03-02T15:07:07Z")
**elelle** and **smartie** , I’m no evolutionary biologist, but I’ve noticed that finding the rationale to a biological given fact usually leads to amusing discussions, but seldom anywhere else. There are just too many factors to take into account. For instance, peacocks have extravagant feathers to attract a mate; sparrows are a dull brown so they won’t attract predators. Well, don’t peacocks have predators chasing them? Don’t sparrows need to mate? Stictly evolutionary speaking, all sorts of phenomenons can come about; if they don’t _hinder_ the procreation of the species, they might be passed on the progeny. Traits don’t even need to _favour_ a species; all that is needed is that a trait won’t _hinder_ them. On the whole, Ma Nature works at her designingboard with far less intent, and much more haphazardly, then a Divine Creator would. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [March 2, 2006, 5:20pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/54 "2006-03-02T17:20:00Z")
> [@Maastricht](#): > > **elelle** and **smartie** , I’m no evolutionary biologist, but I’ve noticed that finding the rationale to a biological given fact usually leads to amusing discussions, but seldom anywhere else. There are just too many factors to take into account. > For instance, peacocks have extravagant feathers to attract a mate; sparrows are a dull brown so they won’t attract predators. Well, don’t peacocks have predators chasing them? Don’t sparrows need to mate? > > Stictly evolutionary speaking, all sorts of phenomenons can come about; if they don’t _hinder_ the procreation of the species, they might be passed on the progeny. Traits don’t even need to _favour_ a species; all that is needed is that a trait won’t _hinder_ them. > On the whole, Ma Nature works at her designingboard with far less intent, and much more haphazardly, then a Divine Creator would. I’m no biologist either but I think is is true. It appears to me that natural selection works more by selecting for elimination than by selecting for survival. Those individuals with serious deficiences in mechanisms for survival don’t survive. The species has to get along, for not, with what is left. ---
**Author:** ![Anne\_Neville](https://avatars.discourse-cdn.com/v4/letter/a/b9e5f3/32.png) [@Anne\_Neville](https://boards.straightdope.com/u/Anne_Neville)\ **Post date:** [March 3, 2006, 12:48am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/55 "2006-03-03T00:48:16Z")
> [@smartie](#): > > “Women’s periods have been tied to the moon and the lunar cycle for literally thousands of years. Before modern science came along to explain that a woman menstruates because of her changing hormones, it was generally accepted that a woman’s periods followed the lunar cycle.” Yes, because humans are very good at finding patterns and connections between things, even when they don’t really exist. This is how we get things like astrology, medical quackery, and conspiracy theories. > [@](#): > > After all, the moon controls the ocean, why not women’s bodies? [Tidal forces, which are how the moon affects the ocean, don’t affect humans, unless the humans in question are the size of a small planet.](http://www.jal.cc.il.us/~mikolajsawicki/ex_tides.html#comments). The Earth experiences tides because the Moon’s gravity at the surface directly under the Moon is stronger than the Moon’s gravity at the center of the Earth. Gravity falls off as 1/r[sup]2[/sup]. The Earth’s surface is about 6378 kilometers closer to the Moon than the center of the Earth is. That’s 1/60 of the distance between the Earth and the Moon. A person’s height is of order one-billionth the distance to the Moon. You just aren’t going to get significant tidal forces in such a small object. > [@lorinada](#): > > Maybe, just maybe, if all us gals concentrated real hard and tried our best, we could menstruate just about whenever we wanted! I will myself to menstruate every month. So far, it’s always worked, as long as I do it at about the right time 😃 ---
**Author:** ![Eleusis](https://avatars.discourse-cdn.com/v4/letter/e/f4b2a3/32.png) [@Eleusis](https://boards.straightdope.com/u/Eleusis)\ **Post date:** [March 3, 2006, 9:33am UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/56 "2006-03-03T09:33:03Z")
Menstruation? Gross. 😉 ---
**Author:** ![Cartooniverse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cartooniverse/32/3084_2.png) [@Cartooniverse](https://boards.straightdope.com/u/Cartooniverse)\ **Post date:** [March 3, 2006, 2:13pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/57 "2006-03-03T14:13:42Z")
> [@Anne Neville](#): > > I will myself to menstruate every month. So far, it’s always worked, as long as I do it at about the right time 😃 Were I a woman, I’d ask permission to use this as a sig line. I’m not. I’m **still** tempted to ask. 😉 ---
**Author:** ![Anne\_Neville](https://avatars.discourse-cdn.com/v4/letter/a/b9e5f3/32.png) [@Anne\_Neville](https://boards.straightdope.com/u/Anne_Neville)\ **Post date:** [March 3, 2006, 5:30pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/58 "2006-03-03T17:30:13Z")
> [@Cartooniverse](#): > > Were I a woman, I’d ask permission to use this as a sig line. > > I’m not. > > I’m **still** tempted to ask. 😉 Use it if you like. My amazing willpower also accomplishes other things: I am currently willing it to stay light later each day. I will it not to rain in California in the summer (this mostly works). ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [March 3, 2006, 5:45pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/59 "2006-03-03T17:45:12Z")
> [@Anne Neville](#): > > I will it not to rain in California in the summer (this mostly works). You’re from the Bay Area and you say this? One time when I was stationed in Merced my wife and I went to San Francisco for a weekend in July. I wore a light, summer, worsted suntan uniform and my wife a light silk dress. Going across the bay on the ferry from Oakland to San Francisco I thought we would freeze to death. It rained both days. Didn’t Mark Twain say that the coldest winter he ever endured was a summer in San Francisco? ---
**Author:** ![Anne\_Neville](https://avatars.discourse-cdn.com/v4/letter/a/b9e5f3/32.png) [@Anne\_Neville](https://boards.straightdope.com/u/Anne_Neville)\ **Post date:** [March 3, 2006, 8:00pm UTC](https://boards.straightdope.com/t/menstruation-and-the-moon/345021/61 "2006-03-03T20:00:36Z")
> [@David Simmons](#): > > You’re from the Bay Area and you say this? One time when I was stationed in Merced my wife and I went to San Francisco for a weekend in July. I wore a light, summer, worsted suntan uniform and my wife a light silk dress. Going across the bay on the ferry from Oakland to San Francisco I thought we would freeze to death. It rained both days. > > Didn’t Mark Twain say that the coldest winter he ever endured was a summer in San Francisco? Doesn’t rain much in the summer in the East Bay, over the hills from Oakland, where I live. And I never said I willed it to be warm in the summer… 😉 [Previous page](https://boards.straightdope.com/t/menstruation-and-the-moon/345021.md?page=2) [Next page](https://boards.straightdope.com/t/menstruation-and-the-moon/345021.md?page=4)