In a long-term study of the Tsimane, researchers find productivity and social status peak long after physical strength. Photo credit: Paul Hooper

Aging Gracefully In The Rainforest, Eurekalert, May 2017

Excerpts:

The Tsimane of Bolivian Amazonia aren’t so different from the people living around you. Most adults live to 70, a few even to 90. They start aging in their 30s, just like the rest of us. And for the Tsimane, the onset of physical aging isn’t really tantamount to decline. Between the ages of 40 and 60, many individuals reach a social and economic peak when hard work and life experience bear their fruit.

In an article that appears in the current issue of Evolutionary Anthropology, researchers synthesize over 15 years of theoretical and empirical findings from long-term study of the Tsimane forager-farmers. This project — the Tsimane Health and Life History Project — sought to understand the human life course outside the context of industrial civilization. It followed a number of complex variables, from biomarkers related to health and aging, to surveys of social status, to observations of economic productivity.

“This project is really an example of big data outside the narrow industrialized context,” explains co-author Paul Hooper, an anthropologist based at the Santa Fe Institute. “The story the Tsimane bear out, through a mountain of data, is the story of all humanity. It’s the ability of a human to produce resources and support the people that they care about later in life, in the 40s, 50s, and 60s.”

Hooper credits adaptation, experience, and maturation for bringing about these late-life benefits. Although their physical strength peaks in their 20s, Tsimane men in middle and older age adapt by devoting less time to hunting and more to horticulture. Tsimane women divide their time between horticulture, food processing, and childcare. While less physically demanding than hunting, horticulture is productive enough that Tsimane between 40 and 70 wind up producing the majority of calories for their extended families. And, because members of older generations are identified as being the best storytellers and advisors, their social stock also rises with age.

“We were able to see that as adults age and their bodies become weaker, instead of ceasing to be productive, folks adaptively shift their behavior into arenas where their aging bodies perform quite well,” Hooper explains.

From an evolutionary standpoint, the findings suggest that human fitness cannot be measured outside of complex social and intergenerational contexts; that our relatively long human lifespans may have evolved to maximize not only individual survival, but also the survival of children and grandchildren. Aging, then, can be understood as a passing of resources and wisdom to the next generation.

The reality of aging, particularly for humans, is that there’s a potential for really high performance and quality of life remarkably late into the aging process.”

This struck me: “human fitness cannot be measured outside of complex social and intergenerational contexts.” The anti-aging movement, the life-extension movement, these are being pursued with an individual focus. They are asking, “How can a human being, an individual, separate and distinct from the beings around it, live a longer and healthier life?” But this study of the Tsimane show that we are not so separate from our surroundings, from the people around us.

When people are respected and valued and nurtured, they thrive. Their health and longevity reflect that care. Is the reverse true? When people are marginalized, do they suffer poorer health?

The Lancet Public Health: Ageism Linked To Poorer Health In Older People In England, Eurekalert, 3 April 2019

They describe health effects linked to age discrimination and speculate on reasons:

Exposure to age discrimination can provoke stress responses harmful to both mental wellbeing and physical health.
…
People may use unhealthy behaviours, like smoking, drinking, poor diet or physical inactivity [I’ll add here use of prescription or illicit drugs], to cope with experiences of age discrimination.
…
Age discrimination in healthcare could mean that older patients are not receiving the same standard of care as their younger counterparts.

People can internalize discrimination. They come to see themselves, even subconsciously, through a filter of how society sees them. I think this is at the root of people trying to look, think, and act younger. Youth is valued in our society, age not as much.

There’s a lot we can learn from the Tsimane.

Jose, a member of the Tsimane group who is 75 years old, stands in the plantain field he planted in Bolivia’s Amazon rain forest. Photo: Matthieu Paley/National Geographic. Source: NPR: Who Has The Healthiest Hearts In The World?