^^ Hey there are many who believe that is a cause still now. The whole thing is odd though because there are studies that show girls without their biological father in the house usually begin their cycle at a younger age. They believe there is some hormonal process that delays puberty when the daughter is near the bio father. Heck look at how women who live together end up on the same cycle yet scientists are split and say there is no proof that pheremones cause a shift.