While the study didn’t go into why these geographic discrepancies exist—“your guess is as good as mine,” Deaton said—he did offer a few common-sense theories. “In the high-income English-speaking world, the elderly get treated very well indeed,” he said; in places with poor healthcare, no social safety net, or cultural disdain for the old, by contrast, the negatives of aging may outweigh the perks of “emotional wisdom.”

But, he added, the particular distribution of each well-being curve is likely generation-specific, with present-day feelings shaped at least partially by the events a person has witnessed over his or her lifetime. With the former Soviet Union countries, for instance, “The collapse of communism was terrific for younger people, who could come to the United States, go to graduate school, all those sorts of things,” he explained. “But for older people, they lost a lot of their pensions, they lost a lot of their healthcare. So it was very bad for them, and you can see a sharp decline with age.”

A generation from now, in other words, the relationship between age and well-being—across the board—will likely look different still.