Last Updated on October 12, 2026 by Karl Thompson
The Harvard Study of Adult Development may be the longest continuous longitudinal study in the world.
Since 1938 it has tracked the lives of 724 men, year after year asking them about their health, their home life and their work. When the study’s director, Robert Waldinger, gave the talk above in 2015, the study was 75 years old, about 60 of the original men were still alive and taking part, most of them in their 90s, and the researchers were beginning to study their more than 2,000 children.
The study followed two groups of men: one group of Harvard University students, and another group of boys from the poorest neighbourhoods of Boston, who typically lived in tenements in the 1930s.
One of the key findings is that being in close relationships is the best predictor of leading a long, happy and healthy life.
The findings of the study are many and varied, but the video above outlines some of the most interesting, which are relevant to the families and households module in A-level sociology.
Key Findings from the Harvard Study
The lessons are not about fame, or wealth, or working harder and harder. The clearest message of this 75-year study is that it’s mainly good relationships which keep us happier and healthier.
Firstly, social connections are really good for us and loneliness kills. People who are more socially connected to family, friends and community are happier, physically healthier, and live longer than those who are less well connected. People who are more socially isolated than they want to be are less happy, their health declines earlier in mid-life, as does their brain function, and they die younger.
The sad fact is that at any given time, more than one in five Americans will report that they are lonely (Waldinger’s 2015 figure).
Secondly, it’s the quality of the relationships you have that matters, not the type of relationship or the number of relationships. Healthy longevity is not (surprisingly?) associated with being in a committed relationship, or having lots of friends.
In fact, being in a “toxic relationship” where you’re constantly facing conflict is perhaps worse for your health than getting divorced! And living in the midst of warm relationships is protective of health.
The level of satisfaction with one’s relationships at age 50 is a better predictor than cholesterol levels of being in good physical and mental health at 80: those who were most satisfied in their relationships at age 50 were the ones most likely to go on to become healthy octogenarians.
Good close relationships also seem to buffer us from physical problems related to ageing: those who experienced physical pain in their 80s reported better mood levels if they were in good-quality relationships.
A third lesson is that good relationships don’t just protect our bodies, they protect our brains. People in close relationships they can rely on keep sharper memories for longer, while those who feel they can’t rely on their partner experience memory decline earlier.
A couple of qualifications
Being in a “good relationship” doesn’t mean couples don’t argue and bicker, that’s just part of any relationship!
All of the above only applies to people who want relationships.
Just for emphasis: in the above study, a “good relationship” doesn’t exclusively mean being in a committed long-term relationship with one person. It might mean having close friends.
The Harvard study today
The study is still going. It now includes the original men’s wives and more than 1,300 of their descendants, which makes it a two-generation study, and it has now been running for more than 85 years.
Relevance to A-level sociology
This is great material to evaluate various aspects of the families and households module.
You could also use it to criticise the obsession some of us have with gaining followers on social media… judging by this study, this doesn’t seem like such a good way to achieve health, happiness and longevity.
It is also a good example of a longitudinal study for the research methods part of the course. For the strengths and limitations of this research design, see my post on longitudinal studies.