Nature’s secret to longevity? It’s all about who you hang out with

OXFORD, United Kingdom — From meerkats to macaques, social animals tend to live longer, take more time to reach maturity, and have more extended reproductive periods than their more solitary counterparts, according to research from the University of Oxford.

Living in social groups comes with clear tradeoffs. On one hand, social animals can share resources, protect each other from predators, and help raise offspring together. On the other hand, they face increased risks of disease transmission, competition for resources, and social conflicts. Yet despite these challenges, scientists say the benefits of social living appear to outweigh the costs across the animal kingdom.

The study, published in Philosophical Transactions of the Royal Society B, examined 152 animal species across 13 taxonomic classes, from jellyfish to humans, providing the first broad evidence that sociality shapes animal life patterns across diverse species.

Previous research on the relationship between social behavior and animal demographics has typically focused on single species or specific groups like birds or mammals. This new study takes a wider view, examining how social behavior influences life patterns across the entire animal kingdom.

Rather than simply categorizing animals as either social or non-social, the researchers developed a novel spectrum of sociality with five distinct levels. At one end are solitary animals like tigers and cheetahs, which spend most of their time alone except for breeding. In the middle are “gregarious” animals like wildebeest and zebras that form loose groups, and “communal” species like purple martins that share nesting areas. “Colonial” species like some wasps and coral polyps always share living spaces. At the far end of the spectrum are highly social species like elephants, most primates, and honeybees, which form stable, organized groups with complex social structures and cooperative breeding.

This nuanced approach to classifying sociality helped reveal patterns that might otherwise have remained hidden. The study found that more social species not only tend to live longer but also have extended “reproductive windows” – the period during which they can successfully produce offspring. They’re also more likely to reproduce successfully before dying compared to less social species.

Consider the difference between social meerkats and solitary tigers. Meerkats live in cooperative groups where multiple individuals help raise young, take turns watching for predators, and maintain complex social hierarchies. Tigers, in contrast, are largely solitary except when mating or raising cubs. The research suggests that the meerkat’s social structure may contribute to their relatively long lifespan and extended reproductive period compared to similar-sized solitary animals.

However, the study also revealed some surprising findings about population resilience. While more social species showed greater resistance to environmental disturbances, they demonstrated lower ability to take advantage of favorable conditions compared to less social species. This suggests that while social living might provide individual advantages, it doesn’t necessarily help populations adapt quickly to environmental changes.

Interestingly, the research found no clear connection between sociality and senescence – the rate at which animals age or experience reproductive decline. Whether an animal lives in complex social groups or leads a solitary life doesn’t seem to affect how quickly it ages or loses reproductive capability over time.

The findings have particular relevance in our post-COVID era, where humans have experienced firsthand the impacts of social isolation.

“Sociality is a fundamental aspect of many animals. However, we still lack cross-taxonomic evidence of the fitness costs and benefits of being social. Here, by using an unprecedented number of animal species this work has demonstrated that species that are more social (most monkeys, humans, elephants, flamingos, and parrots) display longer life spans and reproductive windows than more solitary species (some fish, reptiles, and some insects),” says lead author Rob Salguero-Gómez, an associate professor with Oxford’s Department of Biology, in a statement.

“In a post-COVID era, where the impacts of isolation have been quite tangible to humans (a highly social species), the research demonstrates that, across a comparative lens, being more social is associated with some tangible benefits.”