One hardly needs a list of blue zones to think of commonsense ways to improve life span. We can invest in biomedical research and enact laws and regulations to reduce pollution, design walkable neighborhoods, establish safe public spaces, create affordable housing, and curb smoking. Such strategies might not trend on TikTok, but they would be more effective than the latest juice cleanse. Unfortunately, the pursuit of longevity—like so much else in American life—is increasingly an individualistic endeavor. We adopt new health fads as though they are forms of personal expression, experimenting with cold plunges and red-light therapy, wearable devices and peptide injections. Though it’s nice to think that striving to be healthy is cool or popular—it wasn’t always—the quest for extending life can become monomaniacal, and we easily forget that one’s life span is not, by and large, a life-style choice. Instead, longevity has always been a communal affair.

In the early eighteen-hundreds, a Belgian astronomer named Adolphe Quetelet coined the term “social physics” to describe a method for modelling human development. Stargazers often made small errors when recording the position of planets; the individual errors were unpredictable, but, in the aggregate, they followed a pattern. We now call this pattern a Gaussian distribution, for the astronomer Carl Friedrich Gauss, or, more commonly, a bell curve. Quetelet showed that similar patterns could be found in social phenomena, including births, deaths, marriage, and crime. There was some variation—and, of course, each year there were different people being born, dying, marrying, and committing crimes—but over-all rates were remarkably stable. These occurrences could not be chalked up to individual choices. They were products of measurable—and modifiable—social conditions. A historian later summarized Quetelet’s thesis: “Society prepares the crime, the criminal commits it.”

Not all of Quetelet’s ideas were good ones; he also contended that a person’s physical traits determined social outcomes. Still, it is unfortunate that today’s longevity discourse has become so fully untethered from his sociological point of view. Influencers who peddle supplements and squats are ignoring the enormous role of societal conditions. During my medical residency, in Boston, I spent some of my time seeing patients from Roxbury, Dorchester, and other low-income neighborhoods, where they were more likely to be exposed to crime, drugs, stress, and toxins such as lead. Other weeks, I’d work at a hospital in Newton, a wealthy suburb a few miles away, where kids grew up in large homes on tree-lined streets. In both places, I could offer patients the same basic advice on healthy habits. But it would be absurd to think that my advice helped some Newton residents live into their nineties while many of my less affluent patients might barely make it to seventy. Society prepares the life span; the individual lives it.

Of course, we still have to make decisions about our health. We can’t wait around for governments and institutions—especially this government and these institutions—to bring about the conditions for a wholesome and prosperous society. So what, exactly, should we do? The longevity-industrial complex tends to frame this question in oddly specific ways. Should you eat or avoid eggs? Seek out or shun coffee? Exercise in the morning or the evening? Walk seven thousand steps a day or ten thousand? Nowadays, influencers often invoke scientific research, but it tends to be stripped of context and caveats; they might cite small-animal studies to justify bold recommendations for humans, or argue that everyone can benefit from treatments that are approved for narrow applications. We keep hearing about the new drug that will change our lives. In the two-thousands, David A. Sinclair, a Harvard biologist and a co-author of “Lifespan: Why We Age—and Why We Don’t Have To,” declared that resveratrol, a compound found in grape skins and red wine, was “as close to a miraculous molecule as you can find.” He sold a resveratrol-focussed startup to GlaxoSmithKline. But a researcher at the National Institute on Aging later told the Times that the molecule’s “actual use for humans still needs to be discovered,” and G.S.K. eventually abandoned work on the compound. More recently, in “Outlive: The Science and Art of Longevity,” Peter Attia promoted rapamycin, a molecule that was first sampled on the South Pacific island of Rapa Nui and developed into an immunosuppressant for organ-transplant patients. Laboratory studies have shown that rapamycin could extend the life spans of yeast and mice—but, in a recent randomized human trial, older adults on the medication didn’t seem to experience any physical gains. If anything, they benefitted less from exercise and had more side effects than those who didn’t take the drug; one participant developed a serious infection. Attia and other influencers have said that they have stopped taking the drug, owing to mouth sores, infections, and other complications.