Why do menstrual cycles synchronize in women living together?

[misskitty]

I was going to ask you what that stood for. Stupid questions for 100: is that something all men get of just a few? It seems like my boyfriend (who is 1200 miles away) still seems to get something like that when I have PMS.

 

[selfAdjoint]

Your boyfriend may have "in your face" response, many males do. If someone comes on to them aggressively, they respond aggressively. So your PMS could result in a situation where he snaps back at you.

 

[misskitty]

Oh. So what about the other male PMS symptoms? That's not caused by me because he's reaction to my other PMS moods and such, right?