# menstrual synchronization is not a myth **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [April 14, 2012, 4:10am UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739 "2012-04-14T04:10:05Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![sejuti](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@sejuti](https://boards.straightdope.com/u/sejuti)\ **Post date:** [April 14, 2012, 4:10am UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/1 "2012-04-14T04:10:05Z")
I think some unlucky women are more sensitive than others to this phenomenon. I say this because my cycle length has always been influenced by women (and men) I have gotten close to, although my cycle apparently cannot influence anyone else’s. When I first got my peiords, I had a very long cycle (1.5 months), but within a year or so, I started getting themwithin 4-5 days of my sister’s who is older than me by 6 years. When I first had sex, my cycle lengthened again, but with the end of the relationship, they went back to my sister’s length. After I got married, my cycle went to 28 days, even more perfect than it was when I was with my sis. Then over the last 5 years, I have gotten close to a woman for the first time (we are just colleagues and good friends), my cycle started getting irregular and shorter, closer to 21 days. Only recently, she told me she has a 21 day cycle. Now is this amazing or what??? ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [April 14, 2012, 4:17am UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/2 "2012-04-14T04:17:46Z")
Welcome to SDMB, **sejuti**! When you start a new thread, it’s always a good idea to include a link to the column in question, so we all know what we are talking about. Perhaps [this is the one?](http://www.straightdope.com/columns/read/532/do-the-menstrual-cycles-of-women-living-together-tend-to-synchronize) Column-wise, I can only assume you are agreeing with Cecil. Right? ---
**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\ **Post date:** [April 14, 2012, 4:40am UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/3 "2012-04-14T04:40:56Z")
It’s not at all unusual for a girl’s cycle to be very long the first year or two…or to change length as you age. I don’t live with any other fertile women and mine abruptly shortened from 29 to 26 days when I was 29 or so. Besides, I thought “menstrual synchronization” was supposed to be that one’s cycles matched up with other women so you menstruated at the same time, not had the same length cycle. I lived in a all girls dorm for 4 years, which would seem to be the perfect place for such a phenomena if it really happens, and I can’t tell you how happy I am that there weren’t 150 girls with PMS all at the same time. ---
**Author:** ![Sister\_Vigilante](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@Sister\_Vigilante](https://boards.straightdope.com/u/Sister_Vigilante)\ **Post date:** [April 16, 2012, 4:55pm UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/4 "2012-04-16T16:55:41Z")
It’s confirmation bias. Their periods don’t synch, they just forget what day they started and when prompted, will give the same answer the girl before her did. ---
**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\ **Post date:** [April 16, 2012, 6:39pm UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/5 "2012-04-16T18:39:07Z")
> [@Musicat](#): > > Perhaps [this is the one?](http://www.straightdope.com/columns/read/532/do-the-menstrual-cycles-of-women-living-together-tend-to-synchronize) > > Column-wise, I can only assume you are agreeing with Cecil. Right? I was assuming the OP was _dis_agreeing and referring to the [follow up piece](http://www.straightdope.com/columns/read/2429/does-menstrual-synchrony-really-exist).\ It’s nice to know (or at least imagine) that not only do men not understand how women’s bodies work, women don’t understand how women’s bodies work! ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [April 16, 2012, 7:07pm UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/6 "2012-04-16T19:07:53Z")
> [@SiXSwordS](#): > > I was assuming the OP was _dis_agreeing and referring to the [follow up piece](http://www.straightdope.com/columns/read/2429/does-menstrual-synchrony-really-exist).\ Which shows how important it is to specify, but it doesn’t look like **sejuti** is coming back to tell us. ---
**Author:** ![purplehorseshoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/purplehorseshoe/32/2996_2.png) [@purplehorseshoe](https://boards.straightdope.com/u/purplehorseshoe)\ **Post date:** [April 16, 2012, 7:13pm UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/7 "2012-04-16T19:13:32Z")
> [@elfkin477](#): > > It’s not at all unusual for a girl’s cycle to be very long the first year or two…or to change length as you age. I don’t live with any other fertile women and mine abruptly shortened from 29 to 26 days when I was 29 or so. > > Besides, I thought “menstrual synchronization” was supposed to be that one’s cycles matched up with other women so you menstruated at the same time, not had the same length cycle. I lived in a all girls dorm for 4 years, which would seem to be the perfect place for such a phenomena if it really happens, and I can’t tell you how happy I am that there weren’t 150 girls with PMS all at the same time. As I understand it, it’s not that ALL the girls would synch up, but the ones in closest contact. In other words, roommates (especially BFF roomies) would synch with each other, but not with the girl down the hall. ---
**Author:** ![FrancisCastle](https://avatars.discourse-cdn.com/v4/letter/f/b4bc9f/32.png) [@FrancisCastle](https://boards.straightdope.com/u/FrancisCastle)\ **Post date:** [April 16, 2012, 7:19pm UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/8 "2012-04-16T19:19:04Z")
I work in a small clinic with all women. I’d guess that it took about 6 months to a year, but now I cycle with all the other ladies here. It makes for a fun few days every month! ---
**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\ **Post date:** [April 16, 2012, 7:24pm UTC](https://boards.straightdope.com/t/menstrual-synchronization-is-not-a-myth/618739/9 "2012-04-16T19:24:50Z")
> [@Musicat](#): > > Which shows how important it is to specify, but it doesn’t look like **sejuti** is coming back to tell us. I think our posts are starting to synchronize! Wanna braid each other’s hair? 😉