If you could run one experiment to settle what actually makes a human life go well, it would look like this: take hundreds of people, follow them from youth to death, measure everything, and see what predicts who ends up healthy and happy and who does not. That experiment exists. It has run for more than eight decades. And its answer is clear enough to change how you spend a Tuesday evening.
What is the study?
The Harvard Study of Adult Development began in 1938 and has followed the same people across their entire adult lives, gathering health records, brain scans, interviews, and surveys, generation after generation.1 It is the longest study of human happiness ever conducted, and unlike a one-off survey, it can see what predicts a good life decades in advance rather than merely what correlates with it today.
What did it find?
One finding towers over the rest. The strongest predictor of long-term health and happiness is not wealth, not professional success, not intelligence, not even genes. It is the quality of your relationships.2 The people who stayed most connected, to partners, friends, family, community, were healthier and happier in old age, and they lived longer.
The specifics are startling. Relationship satisfaction at age fifty predicted physical health at age eighty better than cholesterol levels did.3 Loneliness, the study’s directors note, can be as damaging to health as smoking. And this is not a soft, feel-good correlation: it holds up across more than eighty years of hard longitudinal data, which is about as strong as evidence about human lives ever gets.
Why is this so easy to ignore?
Because relationships are exactly the thing that overwork quietly starves. They rarely shout. A missed dinner, a friendship that goes untended, a call you keep meaning to make, none of these produces an urgent alert or a looming deadline. So they lose, every single day, to the work that does. The tragedy the study exposes is that we sacrifice the one thing that reliably predicts a good life for things, status, output, an extra hour at the desk, that predict it weakly or not at all.
The regrets of the dying tell the same story from the other end. The most common are working too hard and losing touch with friends.4 Nobody, at the close, wishes they had cleared more email.
What should you do with this?
Treat it as the answer to the question the whole method is building toward: what is reclaimed time for? You audit your week, kill the pointless work, delegate the shallow tasks, and defend the hours you free, and the Harvard study tells you, with more evidence behind it than almost any claim in this book, where those hours should go first. Toward people. Not as a reward once the real work is done, but as the real work of a life.
This reframes the entire project of working less. It is not about laziness or doing the bare minimum. It is about refusing to let the urgent-but-shallow crowd out the important-but-quiet, and then spending the difference on the relationships that, on eight decades of evidence, are what a good life is actually made of. The study spent eighty-five years discovering what a wiser culture might have simply known. The least you can do is act on it before you need eighty-five years to learn it yourself.
Frequently asked questions
What did the Harvard Study of Adult Development find?
Across more than 85 years following the same people, it found that the quality of your relationships is the strongest predictor of long-term health and happiness, outperforming wealth, social class, IQ, and genes.
Are relationships more important than money for happiness?
On the evidence of the Harvard study, yes, beyond a point. Relationship satisfaction in midlife predicted physical health in old age better than cholesterol did, while wealth and fame were far weaker predictors of a good life.
What should the Harvard study change about how you spend time?
It makes a strong case for treating time with people as a top priority rather than a leftover, and for reclaiming hours from low-value work specifically to invest them in relationships.
About the author
Tom Goodwin is the author of Don’t Work Harder, a book about taking the time AI gives back as time rather than more work. He is a co-founder of GAMEPLAN and writes on productivity, technology, and the economics of the working week.
Footnotes
Footnotes
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Harvard Study of Adult Development; Robert Waldinger and Marc Schulz, The Good Life (2023). ↩
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Waldinger and Schulz (2023): across more than eighty years, relationship quality is the strongest predictor of long-term health and happiness, outperforming wealth, class, IQ, and genes. ↩
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Waldinger and Schulz (2023): relationship satisfaction at fifty predicted physical health at eighty better than cholesterol; loneliness is described as comparably damaging to smoking. ↩
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Bronnie Ware, The Top Five Regrets of the Dying (2011): common regrets include working too hard and losing touch with friends. ↩