I remember reading something where they explained that cultures where they kept the grandmothers around tended to have better outcome for both the mother and th

I remember reading something where they explained that cultures where they kept the grandmothers around tended to have better outcome for both the mother and the baby when their daughters gave birth. It isn't really surprising, when you think of it, and it's probably just one of many examples where aging better, past child bearing age, improves the chances of a lineage.