Studies lend support to 'grandmother hypothesis,' but there are limits

Humans are unusual in that women go through menopause and stop reproducing long before reaching the end of their life expectancy. One theory holds that this aspect of human life history may be explained by the evolutionary benefits associated with the role of grandmothers in helping their grandchildren. Now, two studies add to evidence for this so-called 'grandmother hypothesis.' However, they also show that there are limits.

https://www.sciencedaily.com/releases/2019/02/190207142230.htm