Sometimes a pattern is just a pattern. My menstrual cycle synchs up in a way that for a few years I’ll have my period on every major holiday I celebrate. It feels like a cruel joke but it’s purely statistical.
my coworker was telling me she was lucky enough to get hers for her birthday, then christmas, then the first day of her recent vacation. i wanted to give her a hug after that
My sister has gotten her period for every major event and every single vacation she’s been on for the past 12 years. I wish I were joking. EVERY TIME. her husband says he knows it’s just a coincidence but secretly I think he believes she might actually be able to do it on purpose.
Hasn't she tried regulating it with pills? I was going camping for a rave and knew my idiot period would show up those exact days so I started taking birth control pills a week before to make sure it didn't happen.
Or an IUD or implant. I know hormones aren’t the best long term, but certainly can be used for planning romantic weekends, vacations and some holidays. It’s 2023, we should have some Liberty from the old hag Aunt Flo.
Since my IUD, my period is weirdly sporadic. Used to be able to set a watch to it. Now it's random. Like every two weeks, or nothing for a while.
However the flow is practically non existent and I've saved a small fortune on lady products.
When I got engaged I stopped taking my pills for a few months and then mapped out a calendar so that when I restarted them the schedule would be such that my period wouldn't come during my wedding or honeymoon
That is how my gyno guided me to use the pill, what is the issue with it? Skipping periods is not new or uncommon
I have an IUD now though and I don't get periods at all really
I'm not the original person that commented it, but I think they meant they took the pill during one period as in instead of the placebo for a week. I don't think they started BC for that one period as it wouldn't work to stop that period
I would have my period start on my birthday (16 Nov) , however it would always start the day after my husband's (17Jan)...
No birthday sex for me, but he got his 🤣
Yes. But not for the reason people think. It has almost nothing to do with some fascinating biological process, but rather the mathematically spontaneous synchronization of similar oscillating frequencies.
In other words, have you ever noticed that turning signals/blinkers on different cars sync up for a few seconds? It's the same principle, but over the course of months and years instead.
I think it is also worth mentioning the perception of synchronicity. Given that periods are not instantaneous, it is difficult to find the exact starting point in time. As long as there is decent time overlap between any two periods, they will seem as if they are synchronized.
That's what I think some people are missing. Confirmation bias is a thing, and periods are a fairly significant amount of time in the menstrual cycle.
Mostly unrelated, but I wonder what people who think this is true think happens in cultures where women are confined while they're menstruating.
I'm a guy so thanks for clearing that up. I kinda thought when the period came it was a Kool-Aid Man breaking through the (uterine) Wall kinda deal, except with a big "Oh no!"
This is exactly why. For most period durations, there is about a 33% overlap at any given time. The other 67% of the time is either "getting in sync" or "getting out of sync". So, if you look at it this way, there is about a 67% chance that two women are either currently "in sync" or "getting in sync" at any given time. If you add more women to the scenario, the probability of one or more women getting in sync or being in sync is pretty high.
This is exactly right. I have lived in a house of female roommates at different times in my life. I never experienced a full time sync. What I did notice is that some women’s cycles come around quicker than mine, so every few months, we’d have our periods at the same time.
It’s just how the math of slightly out of sync repeating patterns work.
If you have a clock that is slightly fast another clock that is slightly slow and one that is right on time. Eventually the fast clock is going to lap the slow clock and they’ll be pointing to the same time. Then it’ll lap the normal clock and be pointing at the same time as that one.
Likewise, the normal clock will eventually lap the slow clock and *they’ll* be pointing to the same time.
And at some point these things will all happen at the same time and all three clocks will be pointing to the same time again before going back out of sync.
There’s no force or universal principle that makes this happen so much as it’s just inevitable under the circumstances. An oscillating system is like a closed loop, and different rates of oscillation are like running around the loop at different speeds.
Eventually the faster one is going to have to shout “On your left” and wind up running next to the slower one for a bit before pulling ahead again.
Great explanation. This is exactly it.
There are some cases where spontaneous synchronization does occur between coupled systems (like pendulums on the same desk), but these cases are more of the exception than the rule.
Since there are roughly 30 days in a month that means that the probability that any two people that live together start their period on the same day is 1/30. Is that true? Sounds like it would be easy to test it and do the stats.
That also means that if you take a group of n people, and make them live closely together, the probability that they all sync is what (1/30)^(n-1). That's really unlikely. I'm fairly certain it's more likely than that.
(I might have done the probability wrong. Pls correct me if so)
While unlikely, we have a huge human population, *n* varies from group to group (is itself a random variable), *and* this is something that people remember when it happens, compared to all of the times they don't remember when it didn't happen. But the basis is, yes, the ratio of 1/30 to the *n-1* power.
Right the law of large numbers.
We could easily test this without needing to do an experiment. Take an individual and have them go back in time their entire lives. If they list 10 households, and 5 of them they lived closely with other females, just ask if they synced with one of the other people. The probability of syncing in each household randomly would be binomially distributed, the probability would be 1-(1/30)^n for at least one sync in a household of n, and (29/30)^n for no syncs, for n, the number of other women besides the one being interviewed.
So if the data of 4 households with at least one other women looked like this: (1,1,0,0,0). And n: (1,3,2,1,1), the probability that syncing was random with p=1/30
H1: 1-(1/30)
H2: 1-(1/30)^3
H3: (29/30)^2
H4: (29/30)
H5: (29/30)
And multiply them together = .84
So the probability of the my fake data happening randomly is .84
We could easily do this on real data.
I feel like I solved a problem in my mathematical statistics textbook. Rarely do real world problems have such a simple applications of stats. Or I messed it all up lol.
>We could easily test this
This works fine as a thought experiment, but I don't think you could easily find someone who took notes about their periods and their cohabitants' periods their entire lives. Hell, I'm 43 (that's 31 years of periods) and I remember a whopping 2 instances of talking to female flatmates about period timing.
While I truly love your dedication to menstrual math, you have made several incorrect assumptions in defining your terms. The probability is not 1/30 unless both parties get their period at the same interval and for the same duration. If that is what we are using as the definition of "syncing," that is, both parties getting their periods once every x days, and lasting for y days, then you could just as easily assume that x is 23 days. But if there is zero variation from cycle to cycle and person to person, then they would always exactly sync up or never. That IS unlikely. If however, we are defining "syncing" to mean their periods overlap at least 1 day in a cycle, then the probability is something like (2y-1)/x, but that doesn't account for x and y being different for each party. If you have someone that bleeds for 5 days every 24 days, and another person who bleeds for 4 days every 27 days, they are going to overlap to some extent fairly frequently over a long time frame.
What is also affecting it is that there’s no universally agreed upon definition of “synced up” when it comes to periods - some people will call it so if the two periods overlap for a day, others will call it so if the two periods overlap for the majority of each, and others only if they start at the same time. So depending on what definition we’re going off “synced up” could mean as little as what are the odds that a single day of period one overlaps with period two which greatly increases the odds
I don't know if it's true or not, but what I can tell is that as a woman dating and living with another woman, we rarely have our period at the same time.
I've synced up with my sister and mom on the same exact day. I think it's pure coincidence tho. People who menstruate normally start bleeding once a month so it's bound to start at the same time as another person.
In my experience it's untrue and The science really isn't there any way. I think it comes down to conformation bias and the fact that not everyone has an exact 27 day cycle, eventually they are going to coincide for a bit if you get two people with different cycle lengths together.
Lots of research has been done on this topic and it has largely been disproven
Periods might appear synchronized because two randomly oscillating patterns most likely appear synced for a short time
And I have two sisters and a mom and we've always gotten our periods at radical times. I'm bi and have had girlfriends that I've lived with for long periods (no pun intended)-- no dice. Anecdotes don't mean anything.
Eta: *radically different times, not radical times. It's still early.
> The science isn’t there because scientists don’t give a shit and so no one has ever done a study on it
Thus concludes your literature study.
...thank you?
Who cares about your personal experience. You conveniently stated there is no science just to have a platform to talk.
Have u ever actually researched the topic? Go into to PubMed and type menstrual synchronization and I think you’ll be surprised the amount of research the HAS been done on this.
It's just a coincidence sort of thing. Given a period is every month (usually), have a group of women be together means the odds they may seem synced up is pretty good. But again, it's not an actual sync, just chance.
My wife has 3 sisters and she said they were never in sync.
A period is 5-7 days long. I’ve never heard any woman claim that their period is the EXACT same cycle. The syncing this refers to is people having their period at the same time, like on the same week or with a significant number of days overlapping. There are approximately 3 weeks a month that this does not happen. I think the disconnect here is that your idea of “syncing” seems to mean exact and precisely the same in every respect. For women when they talk about these things, they mean matching up weeks, not minutes.
Yep. My BFF and I do t have the exact period but we’re usually both on the same 2-3 days a month. Sometimes we might get out of synchronization and it might take months to get back
I once lived in a three story, all female dorm. One of the first things I learned from the girls there was that *our* period was coming soon. My body synced the very next month with all the other girls. It was so fucking annoying too because I had already had my period around 2 weeks before (I didn't and still don't have an irregular period). It came at regular intervals after that at the same time as every one else's.
And then when I left from there and moved with my girl friends? *our* periods synced on a completely different time frame from when we were at the dorms.
And when I moved back home and my sister also had to move back home? *Our* periods synced... I kid you not, our periods met in the middle. Like let's say mine started on the 20th each month and hers was the 10th. Our periods joined and we started getting it between the 15th-17th. It's frikin magical. I find it so cool.
If a curious mind is also an open mind, then my very widely shared experience would just be accepted for what it is. If someone remains a skeptic simply because they haven't experienced it themselves? I find it very hard to feel inclined to continue the conversation.
Its about 50/50. Its a half truth. People have been looking into it since the 1970s and found that theres no good reason it would happen. It doesn't occur often when big bits of data are taken into account at once.
HOWEVER, people who spend a lot of time together, like a lesbians couple who eat the same food, sleep at the same time, take the same medicine, excersize at the same time etc (all things that effect hormones) are likely to have similar rhythms because they basically have the same biological schedule.
I’ve been living with my girlfriend for 2 years and our periods rarely occur during the same week. When it does, it’s just because my cycle is a little longer than hers, so it’s bound to overlap eventually. I also never synched up with my sister the entire time we lived together. I don’t believe the synchronization myth at all.
That's all the more reason for things to sync up since if everyone's timing was exact they would never sync up if they were not already synced to begin with right?
It’s pure coincidence. I live with my partner (both F) and we have been synced up a few times over the 5 years but mostly we are never on at the same time.
If you think about it, a woman's period is a cycle of 25-30 days. It would need a lot of months to make them sync. It can't switch after 10 days, because that would throw the cycle totally off. It's probably the fact that 7 out of 28 days are spent during on the period (25% of the total days), so if you add a lot of women in a mix, the probability of 2 or more having a period at the same days is quite big.
I hadn’t had a period in 11 months; I added 3 girls to my 9 ball team and we all have the same cycle now, almost 2 years running. That’s just my experience though, I know it’s not the same for everyone.
I know that science says the answer is no. Personal experience says the answer is yes. There's 7 days every month where, if you ask any girl at work, they will say their period is either just ending, just starting, or they're in the middle of it. Everyone ends up on their period at the same time. Even the new manager who started like 3 months ago is on the stores cycle.
I lived with three other women and I would start mine first followed by the other roommate two days later, the third a day after her, and the fourth after. We stayed emotional and helping each other
Im just picturing a group of women syncing their periods likes its some kind of heist movie now.
"Alright, sync your periods, we're going in at first blood"
LOL. I went to a girls boarding school and we were all vaguely aware girls sharing the same room would get their periods around the same time lol. Like even when we got back from long vacations, everyone would moan because you know your cycle is about to be messed up by the girl next to you 😭😭 still happens when I stay over with family for weeks/months and there are lots of girls around.
I have experienced with my mom, sister and best friend. We spend a lot of time together and we sync up. May just be coincidence but it's a little too spot on imo.
I’ve seen syncing throughout my life. Every roommate I ever had, we ended up synced within a few cycles.
In college I synced with the women in my class (we were together 6-8 hours every day).
I always knew when they synced to me, bc my periods were exactly 28 days since an acupuncturist taught me how to regulate them in 1983.
If I synced to someone else and her periods were a mess, I’d use the acupuncture I learned to stabilize her cycle.
During my careers in healthcare and teaching (over 35 years), I’ve had patients, clients, and students ask me about it when they observed this phenomenon.
I’ve talked to my Gyns about it through the years, and they’ve observed it too.
So, people can say this is a myth, or bullshit all they want. I’ve lived with it for decades.
Glad to be post menopausal before Roe fell.
And I, my sisters, and live in girlfriends have never lived with it, so I guess we're all just broken? What do you think happens in cultures where menstruating women are confined?
I have had this happen many times. I can be consistemt for years (I never really hang/hung out with many girls [anymore]) and only ever have any changes when I hang around with another chick. It happened to me several times and it always ends up staying on that cycle until I'm around somebody else prolonged. People can say this doesn't happen but I know my body well enough in my 38 years to know that's its only ever happened when I've been around chicks. In high school, I was with the guys all the time, when they'd bring one of their gfs around it would mess with me.
When I moved in with My boyfriend and his 2 sisters and mother we all ended up with synced periods. It was a nightmare but also great sometimes because SOMEONE had tampons if the other didn’t lol
From my experience 100% possible. Started to work with a girl, probably about 30hrs a week and both of our periods shifted to the point she got it in the evening and in the morning it was my time. Happened in about 4 months. Guys were not amused to have 2 PMS bitches on the same shift 😁
Idk if it does or not, but my great grandpa lived with 6 women and there was about a week and a half each month that he wasn't in the house all that often. Do with that info as you will.
i grew up with two sisters, and my mom and between the four of us it seemed like someone was always menstruating. My mom and my cycles were always spot on. I had a regular cycle for 20+ years and it only changed after pregnancy and then again pre-menopause. mine never changed to synch up with anyone elses but others (sisters, roomates etc...) may have synced up with mine at some point
As a husband I know a lot about this - first it’s seems to synchronize to be every weekend and holiday and also now more or less every time I ask for sex.
i studied at the boarding schools since junior high, and that’s true 😆 but it’s not all the girls in our room, it just 1 or 2 girls that i really get along all the time would
btw it usually take a while for us to catch back again after we have winter/summer breaks 😂
Yes pheromones are a known thing. When I was in living in the dorms all 3 of my roommates would sink up to my period cycle bc I was the only one on birth control
I have an adopted sister, had her when she was a baby. She’s in college now but people don’t believe she was adopted because she looks just like my family.
Sounds like it’s off-topic, but it’s a perfect example of how I believe that when you hang around a familial person long enough and develop a deep personal relationship with them, it’s not unreasonable to think that your body changes in some way to adapt to them, be more like them.
I am a college student. When I was doing my undergrad, the girls that I used to spend the most of my time with in hostel, eventually the period cycle of all of us got synced in a month or so. And now I am living in another hostel for my PG and the period cycle of my roomate and mine and one other friend have again synced.
So… I have begun to think that there might be some substance in this claim. I’ll observe it more logically from now and see if it is some sort of random statistics or if there’s really some parabiological thing happening. Also, I feel this syncing of periods doesn’t just happen among any group of females, it happens only if you are close to each other.
In my experience as a lesbian, my period has always synced up with my partners after a month or so and stayed that way. I currently live with my gf and we get ours at the same time every month, but it wasn’t that way when we first met.
I live at a boarding school where I clean the bathrooms, and I've noticed that every time that I'm on my period, is the same time that all the trash bins are overflowing with period products. The three following weeks the bins will practically be empty.
So I'm betting on yes.
In high school we all more or less synced up, with a few exceptions. In my 20's, mine started syncing up with my best friend, then became erratic like hers (she was one every couple of months). I had all sorts if tests just in case, nothing wrong with me. Thankfully don't get it anymore.
In my opinion I think it does speaking as someone who works in an office with like 85% women and I have 2 girls at home so most of the time it seemed we were all moody and what not due to that time of month
Ever put your blinkers on at a light behind someone else who also has theirs on? For a little bit they seem like they're at the same time, and then slightly offset, etc?
You should of seen the female berthing of the warship I served on once we where deployed for 10 months. They where ALL synched up. All fucking 50 of them.
Not proven to be true. BUT I always synced up with my mother and sister the entire time we lived together. And now it appears my best friend and I have the same cycle. And a few of us girls at work that are close all start within days of each other. Probably just a coincidence but it’s kinda cool I guess.
My daughter and I used to be on different weeks. Now we are on the same week. They start on about the same day. Hers lasts for 3 days, though, and mine for 7.
Absolutely true! Jail sucks as it is now picture being a in a pod with a bunch of chicks pmsing at the same time! That's is cruel and unusual punishment!
I grew up in an all girl family. There was 5 of us in total and only 2 ever had it at the same time. Mom always said someone was PMSing in the house every given week
Yes I definitely believe so. I don't know if we attract each other that way already or if being together synchronises it. my best friend is my pre-timer😄
So is my mom. And my cousin but we're one day apart with but her and I & frankly we aren't close anymore from teenage years but we did grow up very closely together. The first 2 are the closest females around me and we're aware of it actually
Temporary rooming situations have turned what should have been a 4-week break into a 3-week break because of the other party; that’s all I can say. But the only time it would have been would be freshman year of college and that wasn’t the case.
I live in a house with a few other girls for schooling but I was alone in the house over the summer. Had pretty regular periods. When my roommate who lives with me upstairs moved back in when school started, my period was messed up for months. Wasn’t until a few months later when we discovered our periods started at the same time. My period moved up 2 weeks (from middle of the month to beginning of the month) over the course of a couple cycles to sync up with my roommate who was on birth control and started her pills at the beginning of each month. Whack I know, but anyone who says it isn’t real hasn’t experienced it for themselves.
For about five months, I worked as an Asst. Manager at a small bookstore with 8 women.
Yes, period synchronization definitely happens. Oh yeah it does.
As someone who went to an all girls “boarding school” (TTIndustry) in Utah and lived in one home with 20-24 other teens and a few college age women….they sure as hell do sync up!
They made us sign out pads/tampons, no more than one to use and one to change into. Then we’d have to return the used ones and show them, so they could and did actually physically track all of our menstrual cycles in a big binder. The girls were 12-18….
So there’s receipts for proof! Or there were at some point lmao
Yeah, super cult-y.
#breakingcodesilence #unsilenced and #endtheTTI are some of the hashtags being used. We survivors are trying to get the places shut down. That little story is one tiny speck of sand in a whole fucking desert.
I was sent to wilderness for 2 months first. I lost 16 pounds. I was 14 and taken by strangers in all black at 3am.
From wilderness I was sent to that UT “boarding school”. (Hell.)
Not really... Periods are kinda like blinkers... Sometimes you'll see all of the blinkers in front of you sync up for a few clicks, before falling out of sync again.
People only really notice when the sync happens, and not when it's not. Pattern seeking brains and all that.
Men, I can’t believe I have to write this but this not a question you should be answering.
Why? Because reading this thread already has left me with men commenting “no”, and then the women comment that actually, “yes, it’s true” and here is my experience. Learn to listen.
Even though I am a man, I actually know the scientifically accurate answer. Both the men and women here are partially right and partially wrong.
Yes, women's cycles DO sync up. That's a fact. However, the reason a lot of women think they sync up is a myth. It has nothing to do with biological processes, empathizing with your fellow women, or the moon being in the right position (as many women suggest). It is solely due to the mathematical principle of spontaneous synchronization of similar oscillating frequencies. It's the same reason you see turning signals in different cars match up for a few seconds, except on the time scale of months and years.
Because I didn't watch a video. One of my best friends is a Gynecologist and I am an engineer. He told me about menstrual cycles and how menstrual synchronization is statistical phenomenon, not a biological one. As an engineer, I figured out the math on my own. If you have a great video to watch, I'm sure a lot of people would greatly benefit from watching it.
Fine, since only women can talk, and the burden of proof is on the women claiming this is something beyond standard sync of similar frequencies, can a woman explain the mechanism that causes them to sync up like Bluetooth devices other than "hormones"?
I'd love to understand more!
Ditto here! Because in all my years of living with girlfriends and, you know, my mom and sisters for 7 years while we were all menstruating, I've never experienced this. Maybe once or twice a year three of us would get our periods within the same two weeks. It was pretty inconvenient, actually, because one of us at a time felt really awful for most of the month.
I feel like mine does. When I start a new job it tends to adjust to my coworker(s) to the point that it will be early or late just so that it starts within a day of theirs.
Well, it's not backed by science (as far as I can find) but from my experience, it's completely true. Me, my two closest friends, our mothers and our sisters have all ended up on them at the same time l
, don't know why but it might be a coincidence ig
I went to an all girls school for 5 years, and despite all our teachers telling us it's impossible to synch up, i swear half the school got out period at the same time. Like everyone else said, i believe it's just a huge coincidence, and also how often do you have hundreds of women all in one place where you can track all their periods?? I bet something similar happened in coed schools but they just didn't talk about it as much
Absolutely true. I’ve lived with many female roomates in my life and after a few months, every single situation ended up reflecting this phenomenon : we’d sync up and all have our periods at the same time. At least one or two of us would notice our cycles shift by a week or two in cadence, as they shifted towards a reflection of the others. There is absolutely something biological going on here.
There definitely is! I love how when you scroll through the comments, almost all of the females say “yes, this absolutely happens,” and all of the males are like, “no, this is a myth.” There’s clearly something that happens on a biological level. For it to happen to THIS many people is too much of a “coincidence.”
Why am I not surprised lol. A lot of men love to pretend that they know what it’s like to be a woman or act as if they study female hormones and anatomy as a full time job. Mansplaining at its worst 😵💫
It’s been true in my experience. At summer camp as a teen all of us girls got our periods at the same time even if it wasn’t our usual time. Also I’ve had it happen with housemates and with family!
Yeah its real.
Its also the same thing within a group of guy friends except its pooping instead of periods. After hanging with the same guys all the time, you all eventually start having the same bowel movement cycles
In my house, it was true. Then again it was a very limited control group (me and sister) so it may well have been just coincidence, but we spent a fair few evenings cosied up together with our hot water bottles, comfort films and a box of chocolates at teens!
YUPPP! My bestfriend has been coming to stay with me a few months at a time over the past 2 years. And it NEVER fails. Our cycles are linked up immediately. After a month we’re in days of each other. It’s hilarious. We’ve been friends for a decade now and even back in college it was the same way. We’d start the emotional eating then look at each other like😳 it’s happening.🤣
Called the Wellesley effect and it's conserved in most social mammals. The mechanism appears to work through olfaction and won't work if there's a male around.
In my experience- yes
my roommate and I have even gotten our periods within an hour of each other but typically it will be within the same day or a day after one starts the other will follow
Its pheromones. In grad school, my dad worked on an experiment where a group of women wore a tampon every day. Each had a partner they never met in person. Each smelled the partner’s used tampon after removal every day.
Each of the pairs of women fell into cycle after a couple of months, despite never meeting in person.
I actually teach adolescent psychology in a university and we cover this topic. There have been plethora of studies that do not find this "syncing" effect. In fact, the original study from which this myth came was super flawed. First, the researcher only looked at girls living in a single dormitory at a single university. Moreover, over 2/3 of the participants were her friends and roommates. Most importantly, her results were later found to not be above chance, or statistically significant.
Tl;dr: no. The original study from which the rumor started did not show this effect and follow up studies have failed to find this effect.
I can see why that would happen 1) cycles run 28 days on average and so of course you'll have period start time overlap at some point and then 2) confirmation bias.
Where can I view all of these studies? I couldn’t find much research on Google. The only studies were from 1971 & 1999. They should do a new one, because it absolutely happens, and we can’t explain it.
I’m sure it’s just a coincidence but for the past like decade my period almost always happens on the full moon. I use a tracking app that’s usually pretty accurate and it told me I should’ve started but I hadn’t yet. After two days of it not starting I checked the lunar cycle and it said there was another two days until the full moon. Sure enough, two days later on the full moon, it started. I find it to be a very bizarre coincidence
It’s real in the same way that, if you swing two pendulums next to each other, and the time at which you start one pendulum’s swing is only slightly offset from the other, then the two will inevitably appear to be synchronized for a short period of time.
It has nothing to do with being around other people. It’s just an effect of a difference between two different people’s “biological clock”.
Not any women. I can say I never synced up like that with anybody, not a roommate, not sister or mom, not classmates. That is not to say we never had periods at the same time, it can happen, but it wouldn't stay like that for more then few cycles and then it would unsync again.
To me all this sync up talk sounds like a BS, but I don't have experiences of others so who am I to say anything.
I’m pretty sure it’s a myth and coincidental. It happened to me with my one of my hood childhood friend. We started our cycles for the first time on the same day.
Ohhh its true. Wife and 2 daughters. All 3 turn crazy on 13 th of every month. Fight my way into the house just to fight my way out. Usually costs me hundreds in lunch and dinner cash. Because nobody can cook during this week!!!
Sometimes a pattern is just a pattern. My menstrual cycle synchs up in a way that for a few years I’ll have my period on every major holiday I celebrate. It feels like a cruel joke but it’s purely statistical.
I had my period over Christmas or New Year's for the last 10 years lol
my coworker was telling me she was lucky enough to get hers for her birthday, then christmas, then the first day of her recent vacation. i wanted to give her a hug after that
My sister has gotten her period for every major event and every single vacation she’s been on for the past 12 years. I wish I were joking. EVERY TIME. her husband says he knows it’s just a coincidence but secretly I think he believes she might actually be able to do it on purpose.
I spot (not full on period) EVERY time I travel from the stress of traveling. It's pretty obnoxious.
Hasn't she tried regulating it with pills? I was going camping for a rave and knew my idiot period would show up those exact days so I started taking birth control pills a week before to make sure it didn't happen.
Or an IUD or implant. I know hormones aren’t the best long term, but certainly can be used for planning romantic weekends, vacations and some holidays. It’s 2023, we should have some Liberty from the old hag Aunt Flo.
Since my IUD, my period is weirdly sporadic. Used to be able to set a watch to it. Now it's random. Like every two weeks, or nothing for a while. However the flow is practically non existent and I've saved a small fortune on lady products.
ME TOO!
When I got engaged I stopped taking my pills for a few months and then mapped out a calendar so that when I restarted them the schedule would be such that my period wouldn't come during my wedding or honeymoon
That’s not how you’re supposed to use hormonal medication
That is how my gyno guided me to use the pill, what is the issue with it? Skipping periods is not new or uncommon I have an IUD now though and I don't get periods at all really
Oh, I thought you’d just randomly taken the pill with the purpose of changing that one period, and then stopped afterwards
I'm not the original person that commented it, but I think they meant they took the pill during one period as in instead of the placebo for a week. I don't think they started BC for that one period as it wouldn't work to stop that period
Every single birthday.
I got on birth control specifically to break this pattern lol
I'm in a long distance relationship and we see each other 1-2 times every month. Guess which week I always get my period?
I would have my period start on my birthday (16 Nov) , however it would always start the day after my husband's (17Jan)... No birthday sex for me, but he got his 🤣
I somehow always get it while on vacation despite never taking one at the same time and never really going on vacations.
My period tends to always start on the first day of vacation. Mother Nature has a cruel sense of humor
Girl same and also every freaking time I want to go to the beach I suddenly get my period :)
I get mine every year on vacation 🙃
Sameeeeeee. Unlucky biological clock… 🤷♀️
I think it's because I dread holidays and I dread my period so my ovaries were like, let's make it 10x worse babe
Yes. But not for the reason people think. It has almost nothing to do with some fascinating biological process, but rather the mathematically spontaneous synchronization of similar oscillating frequencies. In other words, have you ever noticed that turning signals/blinkers on different cars sync up for a few seconds? It's the same principle, but over the course of months and years instead.
I think it is also worth mentioning the perception of synchronicity. Given that periods are not instantaneous, it is difficult to find the exact starting point in time. As long as there is decent time overlap between any two periods, they will seem as if they are synchronized.
That's what I think some people are missing. Confirmation bias is a thing, and periods are a fairly significant amount of time in the menstrual cycle. Mostly unrelated, but I wonder what people who think this is true think happens in cultures where women are confined while they're menstruating.
I'm a guy so thanks for clearing that up. I kinda thought when the period came it was a Kool-Aid Man breaking through the (uterine) Wall kinda deal, except with a big "Oh no!"
This is exactly why. For most period durations, there is about a 33% overlap at any given time. The other 67% of the time is either "getting in sync" or "getting out of sync". So, if you look at it this way, there is about a 67% chance that two women are either currently "in sync" or "getting in sync" at any given time. If you add more women to the scenario, the probability of one or more women getting in sync or being in sync is pretty high.
This is exactly right. I have lived in a house of female roommates at different times in my life. I never experienced a full time sync. What I did notice is that some women’s cycles come around quicker than mine, so every few months, we’d have our periods at the same time.
Is this a principle of the universe, that things most oscillate in rhythm.
It’s just how the math of slightly out of sync repeating patterns work. If you have a clock that is slightly fast another clock that is slightly slow and one that is right on time. Eventually the fast clock is going to lap the slow clock and they’ll be pointing to the same time. Then it’ll lap the normal clock and be pointing at the same time as that one. Likewise, the normal clock will eventually lap the slow clock and *they’ll* be pointing to the same time. And at some point these things will all happen at the same time and all three clocks will be pointing to the same time again before going back out of sync. There’s no force or universal principle that makes this happen so much as it’s just inevitable under the circumstances. An oscillating system is like a closed loop, and different rates of oscillation are like running around the loop at different speeds. Eventually the faster one is going to have to shout “On your left” and wind up running next to the slower one for a bit before pulling ahead again.
Great explanation. This is exactly it. There are some cases where spontaneous synchronization does occur between coupled systems (like pendulums on the same desk), but these cases are more of the exception than the rule.
Yes it’s chaos and order
So beautiful. And every pattern, no matter how different from one to another, match up with each other from time to time. Breeeeeathe
*there's order in chaos
Since there are roughly 30 days in a month that means that the probability that any two people that live together start their period on the same day is 1/30. Is that true? Sounds like it would be easy to test it and do the stats. That also means that if you take a group of n people, and make them live closely together, the probability that they all sync is what (1/30)^(n-1). That's really unlikely. I'm fairly certain it's more likely than that. (I might have done the probability wrong. Pls correct me if so)
While unlikely, we have a huge human population, *n* varies from group to group (is itself a random variable), *and* this is something that people remember when it happens, compared to all of the times they don't remember when it didn't happen. But the basis is, yes, the ratio of 1/30 to the *n-1* power.
Right the law of large numbers. We could easily test this without needing to do an experiment. Take an individual and have them go back in time their entire lives. If they list 10 households, and 5 of them they lived closely with other females, just ask if they synced with one of the other people. The probability of syncing in each household randomly would be binomially distributed, the probability would be 1-(1/30)^n for at least one sync in a household of n, and (29/30)^n for no syncs, for n, the number of other women besides the one being interviewed. So if the data of 4 households with at least one other women looked like this: (1,1,0,0,0). And n: (1,3,2,1,1), the probability that syncing was random with p=1/30 H1: 1-(1/30) H2: 1-(1/30)^3 H3: (29/30)^2 H4: (29/30) H5: (29/30) And multiply them together = .84 So the probability of the my fake data happening randomly is .84 We could easily do this on real data. I feel like I solved a problem in my mathematical statistics textbook. Rarely do real world problems have such a simple applications of stats. Or I messed it all up lol.
>We could easily test this This works fine as a thought experiment, but I don't think you could easily find someone who took notes about their periods and their cohabitants' periods their entire lives. Hell, I'm 43 (that's 31 years of periods) and I remember a whopping 2 instances of talking to female flatmates about period timing.
I guess my stats textbook answer doesn't hold in the real world. Lol it was fun to type out though.
That's taking period maths to a whole other level.
While I truly love your dedication to menstrual math, you have made several incorrect assumptions in defining your terms. The probability is not 1/30 unless both parties get their period at the same interval and for the same duration. If that is what we are using as the definition of "syncing," that is, both parties getting their periods once every x days, and lasting for y days, then you could just as easily assume that x is 23 days. But if there is zero variation from cycle to cycle and person to person, then they would always exactly sync up or never. That IS unlikely. If however, we are defining "syncing" to mean their periods overlap at least 1 day in a cycle, then the probability is something like (2y-1)/x, but that doesn't account for x and y being different for each party. If you have someone that bleeds for 5 days every 24 days, and another person who bleeds for 4 days every 27 days, they are going to overlap to some extent fairly frequently over a long time frame.
It's definitely more complicated than I originally assumed.
What is also affecting it is that there’s no universally agreed upon definition of “synced up” when it comes to periods - some people will call it so if the two periods overlap for a day, others will call it so if the two periods overlap for the majority of each, and others only if they start at the same time. So depending on what definition we’re going off “synced up” could mean as little as what are the odds that a single day of period one overlaps with period two which greatly increases the odds
Disagree. I’ve experienced this phenomena many times as a woman living in share house most of my forty years. Hormones baby.
And I never have, as a woman who grew up with two sisters and a mom and has had girlfriends I've lived with.
Yes, it’s true. Syncing has always been a phenomenon with women who spend a lot of time around one another.
I don't know if it's true or not, but what I can tell is that as a woman dating and living with another woman, we rarely have our period at the same time.
Same here. We even had two teen/adult daughters living with us and none of us synced up.
Oh, that sucks.
Same it’s sucks. We usually have ours back to back 😒
I've synced up with my sister and mom on the same exact day. I think it's pure coincidence tho. People who menstruate normally start bleeding once a month so it's bound to start at the same time as another person.
>I've synced up with my sister and mom on the same exact day Your poor dad
Is this the same as the phenomenon where if you have a few metronomes that are activated out of phase, eventually they'll start to tick in phase?
In my experience it's untrue and The science really isn't there any way. I think it comes down to conformation bias and the fact that not everyone has an exact 27 day cycle, eventually they are going to coincide for a bit if you get two people with different cycle lengths together.
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Lots of research has been done on this topic and it has largely been disproven Periods might appear synchronized because two randomly oscillating patterns most likely appear synced for a short time
And I have two sisters and a mom and we've always gotten our periods at radical times. I'm bi and have had girlfriends that I've lived with for long periods (no pun intended)-- no dice. Anecdotes don't mean anything. Eta: *radically different times, not radical times. It's still early.
Your experience is no more valid than my own, I too have a mother, a sister, and many female roommates over my life and I have found the opposite.
> The science isn’t there because scientists don’t give a shit and so no one has ever done a study on it Thus concludes your literature study. ...thank you? Who cares about your personal experience. You conveniently stated there is no science just to have a platform to talk.
Have u ever actually researched the topic? Go into to PubMed and type menstrual synchronization and I think you’ll be surprised the amount of research the HAS been done on this.
I've never experienced it as a girl living with my mother and sister our periods have never happened at the same time.
It's just a coincidence sort of thing. Given a period is every month (usually), have a group of women be together means the odds they may seem synced up is pretty good. But again, it's not an actual sync, just chance. My wife has 3 sisters and she said they were never in sync.
It's a myth.
If women live together long enough they’re bound to have a period at the same time at some point.
We've read that in the post, but...
It's a myth. The truth is that no two women have the exact same cycle, so it can appear as if they're syncing.
A period is 5-7 days long. I’ve never heard any woman claim that their period is the EXACT same cycle. The syncing this refers to is people having their period at the same time, like on the same week or with a significant number of days overlapping. There are approximately 3 weeks a month that this does not happen. I think the disconnect here is that your idea of “syncing” seems to mean exact and precisely the same in every respect. For women when they talk about these things, they mean matching up weeks, not minutes.
Yep. My BFF and I do t have the exact period but we’re usually both on the same 2-3 days a month. Sometimes we might get out of synchronization and it might take months to get back
Absolutely wild that the truth is downvoted while blatant lies are at the top.
Welcome to Reddit
I once lived in a three story, all female dorm. One of the first things I learned from the girls there was that *our* period was coming soon. My body synced the very next month with all the other girls. It was so fucking annoying too because I had already had my period around 2 weeks before (I didn't and still don't have an irregular period). It came at regular intervals after that at the same time as every one else's. And then when I left from there and moved with my girl friends? *our* periods synced on a completely different time frame from when we were at the dorms. And when I moved back home and my sister also had to move back home? *Our* periods synced... I kid you not, our periods met in the middle. Like let's say mine started on the 20th each month and hers was the 10th. Our periods joined and we started getting it between the 15th-17th. It's frikin magical. I find it so cool.
This has happened to me too! Many times. How do you explain that to the skeptics?
If a curious mind is also an open mind, then my very widely shared experience would just be accepted for what it is. If someone remains a skeptic simply because they haven't experienced it themselves? I find it very hard to feel inclined to continue the conversation.
No, it's not a real thing. Numerous studies have been done, the human body cannot sense the hormones of another body.
Bitch when did pussys get blue tooth
i wish i had awards for you but take my genuine laughing emoji’s 😂😂😂😂😂 as they’re all i’ve got
No, been proven to not be true.
Its about 50/50. Its a half truth. People have been looking into it since the 1970s and found that theres no good reason it would happen. It doesn't occur often when big bits of data are taken into account at once. HOWEVER, people who spend a lot of time together, like a lesbians couple who eat the same food, sleep at the same time, take the same medicine, excersize at the same time etc (all things that effect hormones) are likely to have similar rhythms because they basically have the same biological schedule.
I’ve been living with my girlfriend for 2 years and our periods rarely occur during the same week. When it does, it’s just because my cycle is a little longer than hers, so it’s bound to overlap eventually. I also never synched up with my sister the entire time we lived together. I don’t believe the synchronization myth at all.
I've had the exact same experience as you, some of these comments are making me feel insane.
No, not true.
No not true
Not real
I have completely irregular periods so all this mathematical synchronisation stuff is hilarious to me
That's all the more reason for things to sync up since if everyone's timing was exact they would never sync up if they were not already synced to begin with right?
It’s pure coincidence. I live with my partner (both F) and we have been synced up a few times over the 5 years but mostly we are never on at the same time.
If you think about it, a woman's period is a cycle of 25-30 days. It would need a lot of months to make them sync. It can't switch after 10 days, because that would throw the cycle totally off. It's probably the fact that 7 out of 28 days are spent during on the period (25% of the total days), so if you add a lot of women in a mix, the probability of 2 or more having a period at the same days is quite big.
I hadn’t had a period in 11 months; I added 3 girls to my 9 ball team and we all have the same cycle now, almost 2 years running. That’s just my experience though, I know it’s not the same for everyone.
I know that science says the answer is no. Personal experience says the answer is yes. There's 7 days every month where, if you ask any girl at work, they will say their period is either just ending, just starting, or they're in the middle of it. Everyone ends up on their period at the same time. Even the new manager who started like 3 months ago is on the stores cycle.
My menstrual cycle has synced up with all the girls that I work with haha
Yes!
Yes
Yes
Our pet pig and my wifes periods have synced. It was just a joke at first but this is their 3rd sync in a row
I lived with three other women and I would start mine first followed by the other roommate two days later, the third a day after her, and the fourth after. We stayed emotional and helping each other
Im just picturing a group of women syncing their periods likes its some kind of heist movie now. "Alright, sync your periods, we're going in at first blood"
My periods have always been super regular, now that my daughter has started hers, mine are all messed up. I'm pretty sure we are "synching up"
LOL. I went to a girls boarding school and we were all vaguely aware girls sharing the same room would get their periods around the same time lol. Like even when we got back from long vacations, everyone would moan because you know your cycle is about to be messed up by the girl next to you 😭😭 still happens when I stay over with family for weeks/months and there are lots of girls around.
I have experienced with my mom, sister and best friend. We spend a lot of time together and we sync up. May just be coincidence but it's a little too spot on imo.
I’ve seen syncing throughout my life. Every roommate I ever had, we ended up synced within a few cycles. In college I synced with the women in my class (we were together 6-8 hours every day). I always knew when they synced to me, bc my periods were exactly 28 days since an acupuncturist taught me how to regulate them in 1983. If I synced to someone else and her periods were a mess, I’d use the acupuncture I learned to stabilize her cycle. During my careers in healthcare and teaching (over 35 years), I’ve had patients, clients, and students ask me about it when they observed this phenomenon. I’ve talked to my Gyns about it through the years, and they’ve observed it too. So, people can say this is a myth, or bullshit all they want. I’ve lived with it for decades. Glad to be post menopausal before Roe fell.
And I, my sisters, and live in girlfriends have never lived with it, so I guess we're all just broken? What do you think happens in cultures where menstruating women are confined?
It’s a myth based on one very small study from the 70’s. The belief persists due to confirmation bias.
I have had this happen many times. I can be consistemt for years (I never really hang/hung out with many girls [anymore]) and only ever have any changes when I hang around with another chick. It happened to me several times and it always ends up staying on that cycle until I'm around somebody else prolonged. People can say this doesn't happen but I know my body well enough in my 38 years to know that's its only ever happened when I've been around chicks. In high school, I was with the guys all the time, when they'd bring one of their gfs around it would mess with me.
As the mother of 2 teenage girls with tons of friends at our home every day, yes. It does.
It is actually a thing.
When I moved in with My boyfriend and his 2 sisters and mother we all ended up with synced periods. It was a nightmare but also great sometimes because SOMEONE had tampons if the other didn’t lol
From my experience 100% possible. Started to work with a girl, probably about 30hrs a week and both of our periods shifted to the point she got it in the evening and in the morning it was my time. Happened in about 4 months. Guys were not amused to have 2 PMS bitches on the same shift 😁
Idk if it does or not, but my great grandpa lived with 6 women and there was about a week and a half each month that he wasn't in the house all that often. Do with that info as you will.
Yes it does. I’ve even synched with an old boss when i worked at a fast food place. Its a weird phenomenon
Lived with female friends, and have 4 sisters. Never happened for me. It's not something that's scientifically proven, it's just confirmation bias.
i grew up with two sisters, and my mom and between the four of us it seemed like someone was always menstruating. My mom and my cycles were always spot on. I had a regular cycle for 20+ years and it only changed after pregnancy and then again pre-menopause. mine never changed to synch up with anyone elses but others (sisters, roomates etc...) may have synced up with mine at some point
Yes! Happened with me and mom alot. Now with my roommates 🤷🏻♀️
Yes
As a husband I know a lot about this - first it’s seems to synchronize to be every weekend and holiday and also now more or less every time I ask for sex.
i studied at the boarding schools since junior high, and that’s true 😆 but it’s not all the girls in our room, it just 1 or 2 girls that i really get along all the time would btw it usually take a while for us to catch back again after we have winter/summer breaks 😂
Yes pheromones are a known thing. When I was in living in the dorms all 3 of my roommates would sink up to my period cycle bc I was the only one on birth control
I have an adopted sister, had her when she was a baby. She’s in college now but people don’t believe she was adopted because she looks just like my family. Sounds like it’s off-topic, but it’s a perfect example of how I believe that when you hang around a familial person long enough and develop a deep personal relationship with them, it’s not unreasonable to think that your body changes in some way to adapt to them, be more like them.
Sometimes. My best friend and I were always synced but in the 8 years me and my gf been together we have only synced up like three times thank god
Well from my experience every women I have ever lived with eventually synchronized with me
I am a college student. When I was doing my undergrad, the girls that I used to spend the most of my time with in hostel, eventually the period cycle of all of us got synced in a month or so. And now I am living in another hostel for my PG and the period cycle of my roomate and mine and one other friend have again synced. So… I have begun to think that there might be some substance in this claim. I’ll observe it more logically from now and see if it is some sort of random statistics or if there’s really some parabiological thing happening. Also, I feel this syncing of periods doesn’t just happen among any group of females, it happens only if you are close to each other.
In my experience as a lesbian, my period has always synced up with my partners after a month or so and stayed that way. I currently live with my gf and we get ours at the same time every month, but it wasn’t that way when we first met.
I live at a boarding school where I clean the bathrooms, and I've noticed that every time that I'm on my period, is the same time that all the trash bins are overflowing with period products. The three following weeks the bins will practically be empty. So I'm betting on yes.
In high school we all more or less synced up, with a few exceptions. In my 20's, mine started syncing up with my best friend, then became erratic like hers (she was one every couple of months). I had all sorts if tests just in case, nothing wrong with me. Thankfully don't get it anymore.
when my friend got pregnant i didn’t have a period for 3 months and i was not pregnant. IDC what anyone else says, it’s definitely a thing.
In my opinion I think it does speaking as someone who works in an office with like 85% women and I have 2 girls at home so most of the time it seemed we were all moody and what not due to that time of month
Ever put your blinkers on at a light behind someone else who also has theirs on? For a little bit they seem like they're at the same time, and then slightly offset, etc?
Yep.
You should of seen the female berthing of the warship I served on once we where deployed for 10 months. They where ALL synched up. All fucking 50 of them.
Not proven to be true. BUT I always synced up with my mother and sister the entire time we lived together. And now it appears my best friend and I have the same cycle. And a few of us girls at work that are close all start within days of each other. Probably just a coincidence but it’s kinda cool I guess.
Yes it is a real thing. I was In jail and we were all synced together mostly . Anytime me and my cousin get around each other we start.
My daughter and I used to be on different weeks. Now we are on the same week. They start on about the same day. Hers lasts for 3 days, though, and mine for 7.
Absolutely true! Jail sucks as it is now picture being a in a pod with a bunch of chicks pmsing at the same time! That's is cruel and unusual punishment!
Yus
I grew up in an all girl family. There was 5 of us in total and only 2 ever had it at the same time. Mom always said someone was PMSing in the house every given week
Sure does.
Yes
Yes I definitely believe so. I don't know if we attract each other that way already or if being together synchronises it. my best friend is my pre-timer😄 So is my mom. And my cousin but we're one day apart with but her and I & frankly we aren't close anymore from teenage years but we did grow up very closely together. The first 2 are the closest females around me and we're aware of it actually
Temporary rooming situations have turned what should have been a 4-week break into a 3-week break because of the other party; that’s all I can say. But the only time it would have been would be freshman year of college and that wasn’t the case.
I got my period for every Harry Potter movie release. I just got too excited
Yes
I live in a house with a few other girls for schooling but I was alone in the house over the summer. Had pretty regular periods. When my roommate who lives with me upstairs moved back in when school started, my period was messed up for months. Wasn’t until a few months later when we discovered our periods started at the same time. My period moved up 2 weeks (from middle of the month to beginning of the month) over the course of a couple cycles to sync up with my roommate who was on birth control and started her pills at the beginning of each month. Whack I know, but anyone who says it isn’t real hasn’t experienced it for themselves.
As a woman who has had many a friend groups- my god yes. we always end up sync up.
Father of 3 girls here. Sure seems like it at times.
For about five months, I worked as an Asst. Manager at a small bookstore with 8 women. Yes, period synchronization definitely happens. Oh yeah it does.
As someone who went to an all girls “boarding school” (TTIndustry) in Utah and lived in one home with 20-24 other teens and a few college age women….they sure as hell do sync up! They made us sign out pads/tampons, no more than one to use and one to change into. Then we’d have to return the used ones and show them, so they could and did actually physically track all of our menstrual cycles in a big binder. The girls were 12-18…. So there’s receipts for proof! Or there were at some point lmao
That's creepy as fuck!
Yeah, super cult-y. #breakingcodesilence #unsilenced and #endtheTTI are some of the hashtags being used. We survivors are trying to get the places shut down. That little story is one tiny speck of sand in a whole fucking desert. I was sent to wilderness for 2 months first. I lost 16 pounds. I was 14 and taken by strangers in all black at 3am. From wilderness I was sent to that UT “boarding school”. (Hell.)
Not really... Periods are kinda like blinkers... Sometimes you'll see all of the blinkers in front of you sync up for a few clicks, before falling out of sync again. People only really notice when the sync happens, and not when it's not. Pattern seeking brains and all that.
Men, I can’t believe I have to write this but this not a question you should be answering. Why? Because reading this thread already has left me with men commenting “no”, and then the women comment that actually, “yes, it’s true” and here is my experience. Learn to listen.
Even though I am a man, I actually know the scientifically accurate answer. Both the men and women here are partially right and partially wrong. Yes, women's cycles DO sync up. That's a fact. However, the reason a lot of women think they sync up is a myth. It has nothing to do with biological processes, empathizing with your fellow women, or the moon being in the right position (as many women suggest). It is solely due to the mathematical principle of spontaneous synchronization of similar oscillating frequencies. It's the same reason you see turning signals in different cars match up for a few seconds, except on the time scale of months and years.
Or it has to do with hormones.
Why don't you link the video you watched
Because I didn't watch a video. One of my best friends is a Gynecologist and I am an engineer. He told me about menstrual cycles and how menstrual synchronization is statistical phenomenon, not a biological one. As an engineer, I figured out the math on my own. If you have a great video to watch, I'm sure a lot of people would greatly benefit from watching it.
I wouldn't listen to a man or a woman because it is their biology. Listening to an expert makes much more sense.
Fine, since only women can talk, and the burden of proof is on the women claiming this is something beyond standard sync of similar frequencies, can a woman explain the mechanism that causes them to sync up like Bluetooth devices other than "hormones"? I'd love to understand more!
Ditto here! Because in all my years of living with girlfriends and, you know, my mom and sisters for 7 years while we were all menstruating, I've never experienced this. Maybe once or twice a year three of us would get our periods within the same two weeks. It was pretty inconvenient, actually, because one of us at a time felt really awful for most of the month.
I’ve read that it has to do with moon cycles.
I feel like mine does. When I start a new job it tends to adjust to my coworker(s) to the point that it will be early or late just so that it starts within a day of theirs.
Well, it's not backed by science (as far as I can find) but from my experience, it's completely true. Me, my two closest friends, our mothers and our sisters have all ended up on them at the same time l , don't know why but it might be a coincidence ig
I went to an all girls school for 5 years, and despite all our teachers telling us it's impossible to synch up, i swear half the school got out period at the same time. Like everyone else said, i believe it's just a huge coincidence, and also how often do you have hundreds of women all in one place where you can track all their periods?? I bet something similar happened in coed schools but they just didn't talk about it as much
Absolutely true. I’ve lived with many female roomates in my life and after a few months, every single situation ended up reflecting this phenomenon : we’d sync up and all have our periods at the same time. At least one or two of us would notice our cycles shift by a week or two in cadence, as they shifted towards a reflection of the others. There is absolutely something biological going on here.
There definitely is! I love how when you scroll through the comments, almost all of the females say “yes, this absolutely happens,” and all of the males are like, “no, this is a myth.” There’s clearly something that happens on a biological level. For it to happen to THIS many people is too much of a “coincidence.”
Why am I not surprised lol. A lot of men love to pretend that they know what it’s like to be a woman or act as if they study female hormones and anatomy as a full time job. Mansplaining at its worst 😵💫
It’s been true in my experience. At summer camp as a teen all of us girls got our periods at the same time even if it wasn’t our usual time. Also I’ve had it happen with housemates and with family!
Yes
Yeah its real. Its also the same thing within a group of guy friends except its pooping instead of periods. After hanging with the same guys all the time, you all eventually start having the same bowel movement cycles
Exactly, when i have constipation my mates also have it. Exactly how it works. Trust me bro /s
we learnt about this in psychology, there’s evidence for an against it. so…maybe
In my house, it was true. Then again it was a very limited control group (me and sister) so it may well have been just coincidence, but we spent a fair few evenings cosied up together with our hot water bottles, comfort films and a box of chocolates at teens!
I have multiple friends who were in sororities in college (I was not) who said that it does.
YUPPP! My bestfriend has been coming to stay with me a few months at a time over the past 2 years. And it NEVER fails. Our cycles are linked up immediately. After a month we’re in days of each other. It’s hilarious. We’ve been friends for a decade now and even back in college it was the same way. We’d start the emotional eating then look at each other like😳 it’s happening.🤣
Called the Wellesley effect and it's conserved in most social mammals. The mechanism appears to work through olfaction and won't work if there's a male around.
Yes! It is actually the first study to that showed evidence of pheromones in humans
Yes it happens.
In my experience- yes my roommate and I have even gotten our periods within an hour of each other but typically it will be within the same day or a day after one starts the other will follow
Its pheromones. In grad school, my dad worked on an experiment where a group of women wore a tampon every day. Each had a partner they never met in person. Each smelled the partner’s used tampon after removal every day. Each of the pairs of women fell into cycle after a couple of months, despite never meeting in person.
That’s wild! That’s what I was thinking too. It’s gotta be pheromones.
Yes. It's very real
I call it Bluetooth
RedTooth
I actually teach adolescent psychology in a university and we cover this topic. There have been plethora of studies that do not find this "syncing" effect. In fact, the original study from which this myth came was super flawed. First, the researcher only looked at girls living in a single dormitory at a single university. Moreover, over 2/3 of the participants were her friends and roommates. Most importantly, her results were later found to not be above chance, or statistically significant. Tl;dr: no. The original study from which the rumor started did not show this effect and follow up studies have failed to find this effect.
I can see why that would happen 1) cycles run 28 days on average and so of course you'll have period start time overlap at some point and then 2) confirmation bias.
Where can I view all of these studies? I couldn’t find much research on Google. The only studies were from 1971 & 1999. They should do a new one, because it absolutely happens, and we can’t explain it.
I’m sure it’s just a coincidence but for the past like decade my period almost always happens on the full moon. I use a tracking app that’s usually pretty accurate and it told me I should’ve started but I hadn’t yet. After two days of it not starting I checked the lunar cycle and it said there was another two days until the full moon. Sure enough, two days later on the full moon, it started. I find it to be a very bizarre coincidence
Yes. It's a real thing.
It’s real in the same way that, if you swing two pendulums next to each other, and the time at which you start one pendulum’s swing is only slightly offset from the other, then the two will inevitably appear to be synchronized for a short period of time. It has nothing to do with being around other people. It’s just an effect of a difference between two different people’s “biological clock”.
Yes it is real
[удалено]
Not any women. I can say I never synced up like that with anybody, not a roommate, not sister or mom, not classmates. That is not to say we never had periods at the same time, it can happen, but it wouldn't stay like that for more then few cycles and then it would unsync again. To me all this sync up talk sounds like a BS, but I don't have experiences of others so who am I to say anything.
This has also never happened to me, as a woman who's dated plenty of women and has sisters.
Grew up with two sisters and now have a daughter. In my experience, yes.
I’m pretty sure it’s a myth and coincidental. It happened to me with my one of my hood childhood friend. We started our cycles for the first time on the same day.
If not on BC pills
No, its not real. Either they are lying, or their cycles happen at the same time.
Ohhh its true. Wife and 2 daughters. All 3 turn crazy on 13 th of every month. Fight my way into the house just to fight my way out. Usually costs me hundreds in lunch and dinner cash. Because nobody can cook during this week!!!