odor and humans

Colin Cracknell colinc at cix.compulink.co.uk
Sun Dec 25 13:46:32 EST 1994

I just can't believe in this external cue (I'm not counting the influence 
of one woman on another, but looking for something non-human).

Let's suppose that the free-wheeling frequency is 31 days +/- 3, and the 
external influence is the full moon. That implies that there will be some 
women who will have a natural period of 28 days and lock exactly with the 
moon. There will be others with a strong natural period of 31 days who 
are completely unaffected by the moon. What about those with a weaker 
natural 31-day cycle? They should start off locked to the moon, but 
eventually their natural clock will take over and flip them to 31 days 
(or maybe 29 or 30, with residual lunar influence). Their cycle will then 
drift relative to the phase of the moon, until they start to approach 
synch again, and the moon drags them back into synch, probably with a 
single cycle of about 33 days. AFter this they revert to 28 days, until 
they start to freewheel again. AFAIK this just doesn't happen.

Rather more devastating for your theory: If there's *any* external cue 
that synchs women's periods to (say) 28 days, and it's strong enough to 
disrupt the internal clock, then there should be an enormous peak of 
menstruation whenever that cue reaches its peak. Again AFAIK, taking 
women in general there's no day on which they're more likely to 
menstruate than any other.

colinc at cix.compulink.co.uk | "Specialisation is for insects" [RAH]
                           | "I specialise in insects" [ColinC]
All opinions are my own, but Darter Systems agrees with me.

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