To end the week on a more elevated note:-
It has often been observed that women living in community tend to
synchronise their menstrual cycle.
Also, it is widely believed that the 28-day cycle in humans derives
ultimately from the 28-day cycle of the moon, presumably because of
behavioral patterns during our very long prehistory as hunter-gatherers,
Is there any evidence that where modern communities of women become
synchronised, they have any tendency to converge on a particular phase of
the lunar cycle?