The #1 Predictor of Longevity

Smoking status? Your weight? High blood pressure? Diet? Exercise?All of these matter—but let’s explore what might actually be the most important predictor of longevity.

In recent years, you may have seen headlines about the loneliness epidemic. It’s not just media hype—loneliness is real, and it comes with serious health consequences. In fact, chronic loneliness has been linked to increased risks of heart disease, depression, cognitive decline, and even early death. A lack of sense of community and loneliness are the No. 1 predictors of longevity.

What is a sense of community?

A sense of community arises from regular, meaningful social interactions that foster feelings of belonging and mutual support. As inherently social beings, humans rely on interpersonal relationships for emotional and physical well-being (Baumeister & Leary, 1995). Social connection is not just beneficial—it is essential for maintaining good mental and physical health.

Community can manifest in various forms: participation in religious groups, exercise or hobby clubs, neighborhood associations, friendships, extended family networks, and even marriage status. These relationships provide support, identity, and a shared sense of purpose.

Family relationships, in particular, play a foundational role in shaping our sense of community. A long-term study initiated by Harvard in 1938—the Harvard Study of Adult Development—has followed several hundred individuals over decades to explore what factors contribute most to a fulfilling life. Among its findings: the quality of relationships, especially with parents during early life, has profound impacts on long-term health outcomes (Vaillant, 2002).

One phase of the study examined 126 participants and found that:

• Those with strained relationships with both parents had a 100% risk of developing significant health issues in midlife.

• A strained or merely tolerant relationship with the mother was associated with a 91% risk, while a close and warm maternal relationship reduced that risk to 45%.

• Similarly, a strained or tolerant paternal relationship correlated with an 82% risk, whereas a close and warm relationship lowered it to 50%.

• When both parental relationships were warm and close, the risk dropped to 47%.

While this subgroup represents a limited sample, the results indicate statistically significant links between early familial bonds and adult health outcomes. The study reinforces the notion that emotionally supportive environments are protective against disease and promote long-term well-being.

Marital status has a significant impact on health and longevity, particularly for men. Research consistently shows that married men tend to live longer and enjoy better overall health compared to their unmarried counterparts. Interestingly, even men in unhappy marriages often have better health outcomes than single men (Robles & Kiecolt-Glaser, 2003).

For women, however, the picture is more complex. Studies suggest that marriage does not have the same protective effect on women's health and longevity. In some cases, women may experience increased stress in strained marriages, which can actually harm their health (Umberson et al., 2006). Overall, the quality of the relationship appears to matter more for women than simply being married.

Loneliness Compared to Smoking & Alcohol Use

In a 2023 advisory, U.S. Surgeon General Dr. Vivek Murthy and his team highlighted that lacking social connection can increase the risk for premature death as much as smoking up to 15 cigarettes a day.  This comparison underscores the significant impact of loneliness on physical health.​ The team published a guide, "Our Epidemic of Loneliness and Isolation: The U.S. Surgeon General’s Advisory on the Healing Effects of Social Connection and Community." The 82-page guide is good reading (link below).

Notice that there is a significant decrease in both Social Engagement with Friends and Social Engagement with Others around 2007, which is the year the iPhone came out.

One of the earliest studies to highlight the impact of a sense of community began in the 1960s, focusing on the town of Roseto, Pennsylvania. Researchers compared the health of Roseto’s male residents to that of those in the nearby town of Bangor. Interestingly, both groups had similar lifestyles in terms of smoking and alcohol use, yet the men of Roseto had less than half the rate of heart attacks. The question was: Why? The answer seemed to lie not in their physical health habits but in their social structure. In the 1960s, Roseto residents lived in tight-knit, multigenerational households, maintaining strong family bonds and community traditions brought with them from Italy. High levels of social cohesion characterized the town—neighbors looked out for one another, and there was a strong sense of community.

However, by the 1970s and worsening into the 1990s, that protective effect had disappeared. The heart attack rates in Roseto had risen to match those in Bangor. What changed? Over time, Roseto's close-knit, communal lifestyle had faded. Families became more nuclear, and the strong social ties that once defined the town began to unravel, along with the health benefits that came with them.

This study, often referred to as the "Roseto Effect," became a landmark in showing how community and social connection can directly influence physical health, even beyond traditional risk factors.

Loners who aren't lonely

Some individuals are naturally introverted and prefer limited social interaction. For introverts who genuinely enjoy solitude and do not experience feelings of loneliness, there is no evidence that this lifestyle inherently increases health risks. It’s important to distinguish between being alone and feeling lonely—they are not the same.

Research shows that subjective feelings of loneliness, not simply being alone, are what contribute to adverse health outcomes like depression, cardiovascular issues, and early mortality (Hawkley & Cacioppo, 2010). In contrast, introverts who are content with solitude and maintain a few meaningful connections may experience no negative health effects and may even benefit from the reduced stress of fewer social obligations.

References:

https://www.hhs.gov/sites/default/files/surgeon-general-social-connection-advisory.pdf

• Baumeister, R. F., & Leary, M. R. (1995). The need to belong: Desire for interpersonal attachments as a fundamental human motivation. Psychological Bulletin, 117(3), 497–529.

• Vaillant, G. E. (2002). Aging Well: Surprising Guideposts to a Happier Life from the Landmark Harvard Study of Adult Development. Little, Brown Spark.

• Waldinger, R., & Schulz, M. (2010). The Harvard Study of Adult Development: A 75-Year Longitudinal Study. Harvard Gazette overview of the study.

• Robles, T. F., & Kiecolt-Glaser, J. K. (2003). The physiology of marriage: Pathways to health. Physiology & Behavior, 79(3), 409–416.

• Umberson, D., Williams, K., Powers, D. A., Liu, H., & Needham, B. (2006). You make me sick: Marital quality and health over the life course. Journal of Health and Social Behavior, 47(1), 1–16.

• Hawkley, L. C., & Cacioppo, J. T. (2010). Loneliness matters: A theoretical and empirical review of consequences and mechanisms. Annals of Behavioral Medicine, 40(2), 218–227.

• Cacioppo, J. T., & Patrick, W. (2008). Loneliness: Human nature and the need for social connection. W. W. Norton & Company.