To explore this question, a new study re-examines a popular theory that the rate of aging hasn’t changed—it’s just been delayed by about a decade. But one question in decades of research in human aging remains unanswered: Could the rate of human senescence somehow be changing across generations? Related Story Humans Are Rapidly Aging at 44 and 60It’s a question that’s been pondered for quite some time. “One possibility is that what looks like a change in [the rate of aging] is not biological at all, but historical. “Once we filter out non-senescent mortality and account for the accumulation of shared period effects, [the rate of aging] becomes strikingly consistent,” Patricio wrote.