Morteza Katouzian – “The Grandmother” (1986) Oil on canvas, 80×60 cm
Grandmothers play a crucial role in the human life cycle by helping their offspring to raise families. The importance of grandmothering may have led to the evolution of the long human lifespan and early menopause.
Humans live longer than other apes. Our life expectancy is about 80 years, compared to 40-50 years in chimps. Human females lose their fertility at around age of 50 years, yet survive for another 3 decades or so – much longer than any other mammals survive after the end of the fertile period. The menopause seems to play an important role in our species life course and family structure. By looking after their grown-up daughters and their grandchildren , older women may contribute more to their families success than would be the case if they continued to bear children . Some scientists think that it was the evolution of this system of “grandmothering, that extended our life expectancy and slowed the entire human life course as a side effect, delaying puberty well into teens.