Menopause
The menopause transition typically begins between 40 and 50 years of age (average 47.5). The duration of perimenopause may be for up to eight years. Women will often, but not always, start these transitions (perimenopause and menopause) about the same time as their mother did.
Menarche
Menstruation is a cultural as well as scientific phenomenon as many societies have specific rituals and cultural norms associated with it. These rituals typically begin at menarche and some are enacted during each menstruation cycle. The rituals are important in determining a status change for girls. Upon menarche and completion of the ritual, they have become a woman as defined by their culture.