In 1989, a team of anthropologists studying Hadza hunter-gatherers in northern Tanzania noticed how hard one particular group was working: the grandmothers.

“They were well into their sixties and their productivity was just as great as the women who are still in the childbearing years,” Kristen Hawkes, one of the anthropologists involved, tells Emily.

Historically, women’s primary contribution to society was to give birth– implying post-menopausal women offered no value. We now have scientific evidence to prove that wrong.