Lisa Gillespie/Side Effects Public Media

Getting to Anne Polston’s house is a journey: first, you have to get to Liberty, a town about two hours southeast of Louisville. Then, there’s a winding eight-mile road that’s largely one-lane, and sometimes just gravel.

Grandkids Could Be One Reason Humans Live Long Lives

Dec 3, 2015

For humans, life isn't nearly as short as it is for other primates, whose minds and bodies start to deteriorate around the time they reach the end of their reproductive years. Once an animal has created offspring, it has done the heavy lifting of evolution.

We, on the other hand, can continue on well past the time when the kids have flown the coop and sometimes celebrate birthdays measured in triple digits. So why do our bodies bother holding themselves together when we're no longer passing on our genes?

In a recent piece for Time magazine, Susanna Schrobsdorff presents an unexpected challenge for people starting families later in life. She tells NPR's Arun Rath about the variable she calls the grandparent deficit.