Laura Helmuth, Slate’s science and health editor, answers that question in this engaging article, explaining why “It’s the best time in the history of the world to be a child, a parent, or a grandparent.”
It wasn’t until the Paleolithic era that “old people were basically invented,” writes Hellmuth. Until then, as we know from research by anthropologist Rachel Caspari of Central Michigan University, hardly anyone lived past age 30. Then, some 30,000 years ago, people started living longer. It happened across different hominid populations, so the shift was cultural not genetic. Older people are repositories of knowledge, skilled in avoiding danger and storing food and knowing who’s related to whom—and at passing along these complex skills. In a blog post called The invention of old people, Jason Kottke calls them “a shared cultural hard drive for humans.” That’s when modern humans began to flourish, making art, using symbols, and thriving despite the bitter cold of the last Ice Age. Why 30? That’s old enough to be a grandparent, which conveys evolutionary advantages. Populations increased along with lifespans.
The next big shift occurred some 150 years ago, along with the Industrial Revolution, as more children survived to adulthood, women began having fewer of them, and the proportion of older people increased. Lifespan in the developed world has since doubled, and people over 85 now make up the fastest-growing percentage of the population. Helmuth dismisses the handwringing that typically accompanies this scenario, pointing out that a high ratio of older to younger people is not just an indicator of peace and prosperity. “It’s also the foundation of a civilized society,” she writes. “Things go horribly wrong in societies composed largely of young people.” Less aggressive and impulsive, olders are more socially adept and emotionally stable, and want to make the world a better place. “Something to look forward to,” she concludes. I couldn’t agree more.
The article is part of Helmuth’s series on longevity, and I recommend them all.