A study running for 85 years reveals that relationships are the key to happiness

More that individual achievement, money or material goods, the Harvard Study of Adult Development finds that personal connections create the most meaning in life.

By Nolan Shah

Health is determined by a variety of factors: genetics, diet, sleep, environmental and socioeconomic issues, and even levels of satisfaction and happiness. Within the pursuit of health, healthy aging has taken the spotlight. Researchers are interested in influencing “healthspan” — longevity, but also health quality of however many years someone lives. Few studies have gathered enough qualitative health data to answer the question of which factors have the greatest impact. A study from Harvard University seeks to answer the question: What are the major predictors of healthy aging and sustained life satisfaction?

The Harvard Study of Adult Development, sometimes known as the Grant and Glueck study for its lead researchers, is one of the longest-running longitudinal studies of human development in history, yielding numerous academic publications. The project will reach the 85-year mark this year. It began in 1938, enrolling 268 Harvard graduates and 456 men from inner-city Boston neighborhoods. Across the decades, researchers collected medical records and conducted interviews and questionnaires, all focused on psychosocial and biological processes that can help predict late-in-life health and wellbeing.

One metric has urned out to be more important than any other. Forget genetics, or alcohol usage, or fame, or even power and status. The No. 1 indicator for predicting who will have a happy and healthy life is quality of relationships.

Scientists working on what has been nicknamed the “Harvard Happiness Study” have expanded their research to in a second phase dubbed G2, taking in the children of the original study cohort, along with the original participants’ wives and partners. No matter the group, the results are clear: Just as tending to the body is important, ensuring close relationships is necessary to preserve health and satisfaction. 

These results have been achieved at a time where loneliness and mental health crises are at an all time high. The same technology and social media apps that allowed people to foster closer relationships during the pandemic are proving to be barriers for genuine social connectedness. From TikTok, to Instagram Shorts, to Youtube Reels, people are engaging in isolating practices that deplete their overall life satisfaction. 

Maximizing happiness, according to researchers, requires a balance of hedonic and eudaimonic happiness. The former relates to pleasure and experiences while the latter comes from identifying the purpose and meaning of life. Strong relationships can certainly contribute to both types, but mindlessly scrolling through TikTok can only do so much for hedonic happiness before it starts degrading feelings of pleasure.

“We are acting as high tech processing equipment, which we are certainly not,” says Dr. Christine Whelan, a clinical professor of consumer science at the University of Wisconsin-Madison and adjunct professor at Emory University. “The faster the dopamine hits come, the more hedonic adaptation occurs, so you will need bigger hits and become less satisfied with what you already have.”

Whelan offers a course titled “Consuming Happiness,” which explores how humans buy happiness through expenditure of limited resources: time, energy, and even natural resources. In agreement with the Harvard study, Whelan teaches that to maximize happiness, we must invest in pro-social interactions while keeping true to our individual values.

Many cultures and religions have had historically differing viewpoints on happiness. The Aztecs believed in the idea of riding the balance of life’s “good” and “bad” tides, while the Christian church perpetuated the idea of suffering for the sake of salvation. Even Christianity has gone through phases of changing the way happiness is thought about. A contemporary school of thought known as “therapeutic gospel” portrays pursuing happiness as the central goal of life, with a “Jesus-for-Me” mindset,  ultimately contributing to the idea that happiness should be the most important goal for an individual.

Hyper-industrialization and capitalism has certainly contributed to this focus on individual happiness. However, that was not always the case. In fact, happiness in general is a relatively recent social goal. In the US in particular, the singular life purpose was not to be happy. Wartime efforts during World War II offer a great example for how happiness used to be thought about: as creating happiness for the collective by fulfilling social roles.

The end of the Great Depression followed by WWII, sparked the beginning of an individualism era in the US. The 1960s in particular happened on goals of soul-searching and rejecting capitalist culture, creating the widespread impression that it is better to focus on “me” than “we”. This contributed significantly to economic inequality, and led to more social isolation, as people now view themselves as competing with each other for power and wealth. 

Yet, the idea that happiness scales infinitely with income and status is disproven every day. We are bombarded by headlines of famous entertainers, musicians, and multi-millionaires taking their own lives. In academia, this is known as the “Easterlin Paradox,” named after Richard Easterlin, the first economist to study happiness. According to his research, happiness and income vary among and within nations, yet long-term growth rates of happiness and income are not significantly related. In other words, money cannot buy happiness.

If the quality of relationships and pro-social interactions are the absolute most important determination for a happy and healthy life then the Easterlin Paradox makes sense. Whelan, however, offers a more complex take: “If invested into opportunities that lead to greater and more impactful pro-social capital, then money, among other things, can absolutely buy happiness”.

The World Happiness Report, published in 2019 by the nonprofit Sustainable Development Solutions Network, supports Whelan’s claims, showing an increase in mean happiness as income deciles increase. Contrary to Easterlin’s findings, going from the ninth to tenth decile of income still increased mean happiness in the report. Additionally, according to a 2023 edition of the same report, economic measures of nationwide happiness show Finland as the happiest country in the world. This further disproves the Easterlin Paradox, since Finland’s GDP is 40% lower than that of the US.

With so many metrics for measuring individual and nationwide happiness, it is clear that even as thorough a study as Harvard’s cannot boil down happiness and life satisfaction to only quality relationships. It is however important to prioritize relationships, especially as society trends towards a more individualistic and selfish nature.

The mental health crisis in the United States does not seem to be going anywhere. The U.S ranks just 15th worldwide in life satisfaction and general happiness has decreased dramatically since 2011. Therefore, learning how to cultivate and leverage genuine happiness is a skill society as a whole consistently lacks. Dr. Tal Ben-Shahar, a freelance writer and lecturer who formerly taught two of Harvard’s largest psychology courses, has taken matters into his own hands, creating a curriculum for a masters degree in Happiness Studies. His Happiness Studies Academy platform aims to teach people, from corporate leaders to at-risk populations, how to cultivate happy, healthy, and productive work environments.

Ben-Shahar’s academy can certainly benefit workers. Employee burnout is currently at the same level as during the peak of the pandemic, with more than half of American workers experiencing moderate levels of dissatisfaction. Surprisingly, decreasing employee stress may not be the solution. 

“The problem in today’s world is not the stress, but the lack of recovery”, Ben-Shahar says. “When we introduce regular recovery into our life — through play, meditation, exercise, time with friends, etc. — rather than exhaustion, we feel increasingly stronger. Companies must welcome and encourage recovery.”

In his book Wear and Tear, or Hints for the Overworked — first published in 1871, and possibly the first known study of “neurasthenia” or nervous exhaustion — physician and neurologist S. Weir Mitchell predicted the 21st century’s markedly fast pace and high prevalence of mental illness. So how do we get back to leading healthy and satisfied lives? Ben-Shahar has one simple piece of advice that echoes the Grant & Glueck Study

“Prioritize relationships,” he said. “The most important source of happiness may be the person sitting next to you. Appreciate them, savor the time you spend together!”