Don’t worry — be happy! Or you know what? Do whatever you want, actually. You’re going to die either way, and you may as well do it on your own emotional terms. After years of medical studies linking happiness and longevity, the authors of a big new study politely ask, isn’t it possible that we are getting this backward?
In other words: Maybe unhappiness doesn’t lead to a greater risk of death — it could, in fact, be the other way around. What, the researchers wondered, would happen if they controlled for poor health or other risky behaviors, like smoking? Would the link between happiness and longevity remain?
Nope, not at all, is the short answer. For their new paper, published this week in The Lancet, the researchers examined data on the health, happiness, and death rates of more than 1 million British women, taken from the University of Oxford’s Million Women Study. After their recruitment into the study, the women answered this question: “How often do you feel happy?” The researchers then examined the link between their answers to this question and their likelihood of dying over the following ten years after they began participating in the study.
But to get at this high-stakes version of the chicken-egg question, they excluded women from their study who were already seriously ill; they also controlled for unhealthy behaviors, like smoking or problematic drinking. Their results revealed no link between happiness and mortality, a finding that is inarguably “good news for the grumpy,” as Richard Peto, a professor of epidemiology at the University of Oxford and one of the study’s co-authors, repeated in interviews with both the New York Times and The Atlantic.
Really, this makes intuitive sense: The things that are slowly killing people — smoking, chronic disease, cancer, depression, lack of physical activity — also happen to be the things that tend to make people pretty unhappy. You can infer the researchers’ quiet frustration in one of the standout lines in their paper:
Some previous reports have confused cause and effect. Our findings show that unhappiness is associated with poor health mainly because poor health causes unhappiness and partly because unhappiness is associated with lifestyle factors such as smoking. After adjustment for these factors, no robust evidence remains that unhappiness or stress increase mortality or that being happy, relaxed, or in control reduces mortality.
Or in the (accurate) words of the comment section on virtually every science article ever published online: Correlation does not imply causation.
And this finding has some real importance for people currently being treated for things like cancer — or chronic disease, or alcoholism, or depression, for that matter — in that it serves as a counterpoint to the advice that they’d best adopt a cheerier attitude if they knew what’s good for them. As the Times reported, Peto said one of the major reasons he and his colleagues took on this project is that “there is a widespread belief that stress and unhappiness cause disease,” and that this wrongheaded notion can lead to “a tendency to blame the sick for bringing ailments on themselves by being negative.” Happiness may not prolong your life, but neither will unhappiness alone hasten your death.