If you aspire to have a long and fulfilling life, there are numerous strategies you can adopt. Maintain a nutritious diet. Engage in regular physical activity. Steer clear of smoking and excessive alcohol consumption. Additionally, make it a priority to spend quality time with your friends and family.
Based on findings from the Harvard Study of Adult Development, which is the most extended study on human happiness, fostering strong connections is crucial for both your happiness and well-being.
Harvard Study of Adult Development
This significant research project began in 1938 through two independent studies of human development. The initial study was conducted at Student Health Services, involving 268 Harvard sophomores—all male and around 19 years old—who were chosen to observe “normal” young adult growth and the transition from adolescence to adulthood.
“Essentially, it was a study focused on flourishing—what contributes positively to development,” says Robert Waldinger, M.D., the current director of the research and co-author of The Good Life: Lessons from the World’s Longest Scientific Study of Happiness. He notes the early oversight of the research, commenting, “If you aim to study ‘normal’ development by focusing solely on white males from Harvard, you’re missing a broader picture.”
The second study, initiated in 1940 at Harvard Law School, was directed by professor Sheldon Glueck, Ph.D., alongside his wife, Eleanor, Psy.D., a criminologist with a social work background. Their goal was to explore the roots of juvenile delinquency, seeking predictors of success among disadvantaged youths. They studied 456 working-class boys aged 11 to 16.
George Vaillant, M.D., Waldinger’s predecessor, decided to merge the two studies, believing it would be valuable to compare the different trajectories of both groups. “He wanted to examine how their lives unfolded in contrast,” Waldinger recalls.
Researchers also expanded the study by including the spouses of these original participants and later their children. Over 85 years, the study has followed 724 families, making it the longest-running research project in human development.
“No one anticipated that the study would extend for 85 years. The original researchers would likely be amazed to see its continuation,” Waldinger comments with a grin, being the study’s fourth director.
Robust, healthy relationships can extend your life
Among the study’s most unexpected revelations is the significant influence of relationships on physical well-being. Harvard’s research indicates that strong interpersonal connections are more vital for happiness throughout life than wealth, popularity, social status, or intelligence, effectively delaying both mental and physical decline and lessening suffering.
It intuitively makes sense that community and connections are vital for longevity and happiness, yet the team was astonished by the degree of their importance. “When our data was released, we couldn’t believe it ourselves,” Waldinger admits. “It is logical that strong relationships could contribute to happiness—but how could they possibly correlate with lower risks for Type 2 diabetes? Or arthritis? That seemed unimaginable. Then, other studies began to confirm our findings.”
Ongoing research aims to uncover the “why” behind these results, with the leading theory suggesting that interpersonal relationships aid in stress regulation. Consider this scenario: when an upsetting event happens during your day, having someone to share it with—whether by talking at home or calling up a friend to vent—can initiate a feeling of physical relaxation.
“In stressful situations, our body responds with a fight-or-flight reaction, which is natural,” Waldinger explains. This response can lead to increased circulating levels of stress hormones and inflammation, among other physical changes.
Once the source of stress is eliminated, the body should ideally return to a calm state. However, the theory posits that without someone to confide in, regaining balance can be more challenging. Waldinger notes that individuals who frequently feel lonely or socially isolated often experience a persistent state of chronic inflammation, along with elevated levels of stress hormones.
“This appears to be a pathway through which various bodily systems may be influenced,” he states. “Chronic stress.”
Additional strategies for longevity
The Harvard Study of Adult Development concludes that relationships, while crucial, are not the sole factors in achieving a long and happy life. It’s also essential to take care of your health through proper nutrition, regular physical activity, and avoiding excessive drinking and smoking—“All these elements contribute significantly,” Waldinger states.
Although his research centers on happiness, he emphasizes that there is no need to pressure yourself to feel happy all the time; that expectation isn’t realistic. “Through our extensive research on various lives, it’s clear that no one’s life is devoid of challenges,” he remarks. “Every life encounters unhappiness and difficulties.” Nevertheless, he advocates prioritizing strong, nurturing relationships, whether by calling an old friend or joining a local sports team to meet new people.
When the initial cohort of men from Harvard’s study reached their 80s, researchers asked them to reflect on their lives, sharing their greatest achievements and regrets.
“The most predominant regret,” Waldinger reveals, “was, ‘I wish I hadn’t dedicated so much time to work and had instead spent more time with those I care about.’”
