[sci.bio] Women's periods in synch

samdavis@maelstrom.Berkeley.EDU (Benjamin Davis) (04/16/91)

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samdavis@maelstrom.Berkeley.EDU (Benjamin Davis) (04/16/91)

Sorry about article 4997 - I've never posted an article before, so I
screwed up.  I'll try not to waste your time anymore.

In _The_Straight_Dope_, Cecil Adams explains that the reason women's periods
fall into sync is because of chemicals from their sweat: it seems that some
women are "dominant" in that their sweat causes other women's cycles to fall
in with theirs, and other women are more susceptible to suggestion from the
chemicals around them (I think these chemicals are pheromones?).  So if
women live together or work together for extended periods (no pun intended)
of time, their menstrual cycles will go in sync.
The Straight Dope is a highly interesting collection of trivia - I
recommend it even if you're not (like me) someone who generally likes trivia.

Hopefully this will be my first -successful- posting to the net.  Apologies
again about my mistake (I'm very inept with vi).

fzcapit@MIZAR.UCDAVIS.EDU (John Capitanio) (04/16/91)

In article <1991Apr16.014518.11307@agate.berkeley.edu>, samdavis@maelstrom.Berkeley.EDU (Benjamin Davis) writes:
[stuff deleted]              
>In _The_Straight_Dope_, Cecil Adams explains that the reason women's periods
>fall into sync is because of chemicals from their sweat: it seems that some
>women are "dominant" in that their sweat causes other women's cycles to fall
>in with theirs, and other women are more susceptible to suggestion from the
>chemicals around them (I think these chemicals are pheromones?).  So if
>women live together or work together for extended periods (no pun intended)
>of time, their menstrual cycles will go in sync.
>The Straight Dope is a highly interesting collection of trivia - I
>recommend it even if you're not (like me) someone who generally likes trivia.

I meant to respond to the original post, but...
There has been considerable work, since the 1960s on olfactory signals
(pheromones) and their influence on as pects of reproduction.  Much
of the work has been done on rodents.  The original article demonstrating
(or at least suggesting) pheromonal mediation of menstrual synchrony and
suppression in humans is from M.K. McClintock, Menstrual synchrony and
suppression, *Nature*, 1971, vol. 229, 244-245.  Any good (and actually most
bad) textbooks on animal behavior can provide lots of references on the
rodent (and some primate) work.  I think McClintock has also been involved
with other research demonstrating the role of olfaction in social
identification.  These studies have included having people wear t-shirts
for a couple of days, putting them in jars, then asking people to smell
each one and select their own.  Another study I remember involved
babies discriminating between the breast pads of their own mother and those
of other lactating females.  A much underappreciated sensory system, olfaction.

I forget the references to the above studies.  If anyone has any interest,
let me know.

John
 

mnl@ukc.ac.uk (M.N.Leonard) (04/17/91)

In article <1991Apr16.014518.11307@agate.berkeley.edu> samdavis@maelstrom.Berkeley.EDU (Benjamin Davis) writes:
>In _The_Straight_Dope_, Cecil Adams explains that the reason women's periods
>fall into sync is because of chemicals from their sweat: it seems that some
>women are "dominant" in that their sweat causes other women's cycles to fall
>in with theirs, and other women are more susceptible to suggestion from the
>chemicals around them (I think these chemicals are pheromones?).  So if
>women live together or work together for extended periods (no pun intended)
>of time, their menstrual cycles will go in sync.

I agree with the idea that pheromones secreted within a group of women
living or working together can induce menstrual synchronism but it
gets rather more complex if one or more of the women are taking oral
contraceptives, in this case no amount of exposure to other peoples
pheromones will alter the menstrual cycle. I recall reading a paper
in the dim distant past recording menstrual synchronicity however, the
authors took great care to measure the results from women who were in
an enclosed environment such as prison inmates. I think that if a
group of normal women living together (presumably some of which were
taking "the pill"), there would almost certainly be no synchronisation
of menstruation as each of these women would be secreting the
pheremone's appropiate to the stage of their cycle so no "pheromonal
pull" would exist to alter any womans given cycle.
  
Any Comments

Mike Leonard