About 30,000 years ago, humans started living past the age of 30 at a rate never before seen. Laura Helmeth, writing at Slate about the findings of a study by Rachel Caspari, recently reported that cultural shifts at this point in human history allowed humans to live long enough to become grandparents and that right around this time, human population and culture began to expand and flourish in unprecedented ways, growing larger than ever before, moving into new environments and incorporating art. Having an extra generation around to help raise children and to share a longer-term perspective seems to have given humanity a huge boost:
A lot of skills that allowed humans to take over the world take a lot of time and training to master, and they wouldn’t have been perfected or passed along without old people. “They can be great teachers,” Caspari says, “and they allow for more complex societies.” Old people made humans human.
Longer life is often cited as a benefit of human evolutionary and cultural adaptation, but this work makes the case that it also provided benefits, contributing to a positive feedback loop.
