Less is More: Monkeys Show How Fewer Friends May Keep Us Healthier

A groundbreaking study by researchers at the University of Exeter and the University of Edinburgh reveals a fascinating link between aging, social networks, and health in rhesus macaques

Why Do Animals and Humans Limit Friend Circles as They Age?

When I was a kid, nothing was more exciting than visiting friends’ houses. Running over to someone’s place felt like stepping into a whole new world—new toys, different snacks, and endless games. By the time I hit my teenage years, the thrill only grew: sports, video games, and weekend hangouts were practically a way of life. But as the years pass, I’ve noticed something strange. Each year, that drive to go out, see people, and stay socially active seems to ebb away a little. I’ve also noticed this in my parents, who hardly seem interested in meeting new friends or making new connections. They seem content with their familiar circles. Is it a problem?

This journey, from childhood social butterflies to selective adults, isn’t just a personal feeling. In the animal kingdom, social aging is a real, well-documented process that researchers are just beginning to understand. A fascinating study on rhesus macaques might shed light on why both we and our aging family members naturally draw back from big social circles. By examining how aging macaques reduce social connections, scientists have found surprising clues that could explain why less social engagement might actually benefit us as we grow older. Here’s what they discovered.

The research looked at rhesus macaques—our evolutionary cousins—and their shifting social behaviors as they age. Monkeys, like humans, thrive in groups for protection, learning, and survival. However, older macaques tend to reduce the number of social connections. According to the study, the main finding is that fewer social ties can mean fewer illnesses.

Aging animals face increased vulnerability to diseases due to weakened immune systems. For older monkeys, reducing interactions seems to lower exposure to contagious diseases—a benefit researchers termed a “protective effect” of aging. This protective behavior aligns with similar human patterns, where older adults tend to withdraw slightly from social circles, often to avoid illnesses.

Aging and Infection Risk

The research team analyzed social interactions among a group of adult female rhesus macaques. By modeling these interactions with epidemiological tools, they could simulate disease spread in relation to social behavior.

• Lower Infection Rates Among Older Monkeys: Older macaques, who had fewer social ties, were significantly less likely to catch infections compared to their younger, more socially active counterparts.
• Benefit for Highly Contagious Diseases: This protective effect was most significant when the disease was highly contagious, as the reduced contact limited exposure to other infected individuals.
• Social Centrality and Disease Risk: The study used “social centrality” (a measure combining social connections and time spent interacting) to show that older, less socially central monkeys saw the most health benefits.

Why Social Aging Matters

The study proposes that “social aging” may be an evolutionary strategy. By naturally reducing their social circle, aging animals avoid the downsides of weak immune systems and prolonged recovery times. This behavior could be a subtle form of self-protection, driven by evolutionary pressures.

According to co-author Matthew Silk, the findings may explain why “social aging” is a common trend across various animal species, including humans. As a possible defense mechanism, it seems to guard older individuals against severe illness.

Practical Takeaways

1. Healthier Aging Through Selective Socializing: The research highlights how the quality of social interactions over quantity might benefit aging individuals, both animal and human, by lowering risks of illness.
2. Reevaluating Elderly Social Engagement: In humans, social aging doesn’t necessarily mean isolation but may involve a shift towards fewer, more meaningful interactions.
3. Insights for Public Health: Understanding that older adults naturally avoid certain social exposure could inform health practices, especially in care settings where disease spread is a risk.

A New Perspective on Aging Social Networks

By illustrating how aging animals manage their social networks to reduce health risks, this study offers a fresh understanding of how social interactions evolve with age. The findings encourage us to look at aging not just as a decline in social engagement but as a sophisticated, adaptive strategy to protect health.

As we grow older, staying connected can be both a comfort and a challenge. While studies on rhesus macaques suggest that social aging helps limit exposure to disease, it also highlights the delicate balance between the benefits of connection and the risks of physical proximity. Here, the internet offers a powerful alternative. Online platforms allow older adults to maintain social connections without the health risks that can accompany in-person interactions, creating new avenues for interaction that would otherwise be difficult.

However, as helpful as digital connections are, they come with shortcomings. Virtual communication may lack the warmth and immediacy of real-world interaction, leaving some feeling that something essential is missing. Yet, even with these limitations, online platforms can still foster meaningful relationships, bridge physical distances, and counter the isolation that often accompanies aging.

While having a big network increases exposure to germs, close bonds with a few trusted individuals can offer social and emotional stability without exposing us to as many health risks. As we grow older, choosing to engage with close, trusted friends rather than large social groups could be a natural response to protect ourselves from stress and infection.

Curious for more? Dig deeper into the science of our reference:

Siracusa, E.R., Pavez-Fox, M.A., Negron-Del Valle, J.E., Phillips, D., Platt, M.L., Snyder-Mackler, N., Higham, J.P., Brent, L.J. and Silk, M.J., 2024. Social ageing can protect against infectious disease in a group-living primate.