A bit of new research suggests that the rise of human civilization may have been predicated on increasing lifespans. This allowed older adults to be, well, grandparents. And that allowed them to pass on their knowledge and skill well after their own reproductive lives were over. Kin selection strikes again.
Modern humans began to live long and prosper only about 30,000 years ago, researchers report. Results published online this week by the Proceedings of the National Academy of Sciences reveal a striking increase in human longevity during the Upper Paleolithic Period when the number of people surviving to old age increased four-fold. […]
The findings support the so-called grandmother hypothesis, which posits that older women no longer responsible for their own children help support the group by strengthening social bonds and providing greater opportunities to pass on specialized knowledge. “There has been a lot of speculation about what gave modern humans their evolutionary advantage,” Caspari remarks. “This research provides a simple explanation for which there is now concrete evidence: modern humans were older and wiser.”
Although some might say that H.L. Mencken disproved this hypothesis long ago when he remarked, “The older I grow the more I distrust the familiar doctrine that age brings wisdom.”