The Harvard Study of Adult Development, often called the Harvard happiness study, found that close relationships predicted long, happy lives better than social class, IQ or genes, and that the people most satisfied with their relationships at 50 were the healthiest at 80. [mineo-2017-harvard-gazette] That is an observational finding from one long-running study, and a large review of 148 studies points the same way. [holt-lunstad-2010-relationships-mortality] This guide covers who was studied, what the study found, what it cannot prove, and what to do with it. Our overview of relationships covers the wider field.
What is the Harvard Study of Adult Development?
It is one of the longest studies of adult life ever run. It began in 1938, when researchers started tracking 268 Harvard sophomores in what became known as the Grant Study, and it later added 456 Boston inner-city residents through the Glueck Study. [mineo-2017-harvard-gazette] That makes 724 people in the two original groups.
Researchers have since followed them with medical records, hundreds of interviews and questionnaires, added the men’s wives, and extended the work to their children. A 2017 report from Harvard put the second generation at about 1,300 people. [mineo-2017-harvard-gazette] The study has had four directors. The current one, the psychiatrist Robert Waldinger, set out its lessons with Marc Schulz in a 2023 book, The Good Life. [waldinger-schulz-2023-good-life]
What did the study find about relationships and health?
It found that the quality of close relationships was one of the strongest predictors of health and happiness in later life. The researchers found a strong correlation between the men’s flourishing lives and their relationships with family, friends and community, and several analyses found that satisfaction with relationships at 50 predicted physical health better than cholesterol levels did. [mineo-2017-harvard-gazette] In the director’s words, the people most satisfied in their relationships at 50 were the healthiest at 80. [mineo-2017-harvard-gazette]
Two details add to that. First, marriage quality seemed to protect mood: in a daily-diary study of 47 married couples in their 80s, people in more satisfying marriages saw less of a dip in daily happiness on days when they felt less healthy. [waldinger-schulz-2010-married-octogenarians] Second, relationships were not the only factor. An earlier director, George Vaillant, reported six factors that predicted healthy ageing for the Harvard men: physical activity, no alcohol abuse, not smoking, mature ways of coping, a healthy weight and a stable marriage. [mineo-2017-harvard-gazette]
Do good relationships help you live longer?
They are linked with longer survival across many studies, not only this one. A review of 148 studies with 308,849 people, followed for 7.5 years on average, found an odds ratio of 1.50 for survival in people with stronger social relationships, which the authors described as a 50% higher likelihood of survival. [holt-lunstad-2010-relationships-mortality] The review’s editors gave a plain reading: by the time half of a group of 100 people has died, about five more people with stronger relationships are still alive than among people with weaker ones. [holt-lunstad-2010-relationships-mortality]
The link was strongest for complex measures of social integration, at 1.91, and weakest for a simple question about living alone or with others, at 1.19. [holt-lunstad-2010-relationships-mortality] The authors concluded that the influence of social relationships on the risk of death is comparable with well-established risk factors for mortality. [holt-lunstad-2010-relationships-mortality]
Holt-Lunstad and colleagues (2010): odds ratios of 1.19, 1.50 and 1.91, shown as the percentage by which the odds of survival were higher (the odds ratio minus 1, multiplied by 100). A taller bar means a stronger link with survival.
What can the Harvard study not prove?
It cannot prove that good relationships cause better health. Both the Harvard study and the review are observational, so they show an association. People who are healthy may find relationships easier to keep, and a third factor could shape both. Relationship quality is also hard to measure precisely.
The samples have limits too. The Harvard group was all male at the start, because the college was then all male, and wives were added later. [mineo-2017-harvard-gazette] In the review, 51% of participants were from North America and 37% from Europe, with an average age of 63.9 at the start. [holt-lunstad-2010-relationships-mortality] So the findings may not apply equally to everyone, and the evidence is strongest for older adults in those regions.
What should you do with it?
Treat relationships as something to tend, as you would sleep or exercise. The director put it as taking care of your body being important, with tending to your relationships being a form of self-care too. [mineo-2017-harvard-gazette] The study does not say which actions work, so the steps below are our suggestions and not findings.
- Pick one person. Choose someone whose relationship you would like to be warmer, and make the first move this week with a message or a call.
- Keep contact small and regular. A short, repeated check-in is easier to keep going than a large occasional effort.
- Listen properly. Our guide to active listening covers what makes people feel heard.
- Ask for help. Our guide to asking for help covers why people say yes more often than expected.
- Build new ties. Our guide to making friends as an adult covers how adult friendships form.
How well tended are your close relationships?
Tick anything that is true for you right now. This is a prompt for reflection, not a test, and it produces no diagnosis.
0 of 5 ticked
Most of these are in place. The research is about relationships over decades, so the aim is to keep them going when life gets busy.
A few of these are in place. Pick the unticked item that feels most doable this week and take one small step on it.
Few of these are in place right now, which is common and can change. Start with one message to one person. If loneliness is weighing on you, the loneliness self-assessment can help you see where you stand.
When to seek help
Speak to a doctor or therapist if loneliness, low mood or difficulty with close relationships has lasted most days for two weeks or more, or if it is affecting your work, sleep or health. No screener on this site measures relationship satisfaction. Our loneliness self-assessment measures loneliness, which is related to it but not the same, and it is a screener and not a diagnosis. It can help you decide whether to have that conversation.
If you feel unable to keep yourself safe, contact your local emergency services or a crisis helpline.
How MyFreud can help
Whether time with people is changing how your days feel is hard to judge from memory. Daily mood tracking in MyFreud shows the pattern across weeks, so you can compare the days after you saw someone you care about with the days you did not. It does not replace the people in your life, or a doctor.
Download MyFreud and start today: App Store or Google Play.