Haid: Perbezaan antara semakan

Dikalangan wanita yang tinggal berdekatan, permulaan haid cenderung untuk berlaku serentak. [[Kesan McClintock]] mula digambarkan pada 1971, dan kemungkinannya dijelaskan melalui tindakan [[pheromone]] pada 1998.<!--

--><ref name="Mclintock">{{cite journal | author=Stern K, McClintock MK | title=Regulation of ovulation by human pheromones | journal=Nature | year=1998 | pages=177-9 | volume=392 | issue=6672 | id=PMID 9515961}}</ref>

--><ref>{{cite web | last = Adams | first = Cecil | authorlink = Cecil Adams | title = Does menstrual synchrony really exist? | work = The Straight Dope | publisher = The Chicao Reader | date = [[2002-12-20]] | url = http://www.straightdope.com/columns/021220.html | accessdate = 2007-01-10 }}</ref>

 

==Pautan luar==