Grandma Doesn't Need a Reason

You've probably heard of the "grandmother hypothesis," which says that women go through menopause so that they can live long enough to help their grandchildren survive. It's been a rather popular argument since the 1980s because it makes so much sense. But it turns out that humans didn't invent menopause, and it happens in other species that don't bother taking care of their grandchildren. So we are back to the question of why women tend to live so much longer than men. Back in the days when women were much more likely to die in childbirth, a long life after menopause just kind of evened things out for the lucky ones. Evolution doesn't care how long you live after you're finished reproducing, but Grandma thinks it's kind of neat.