Seven Decades: How We Evolved to Live Longer

The evolution of human longevity still remains a curious puzzle. Here I provide some new perspectives on the why and how of longevity over the course of human evolution, using longitudinal study of subsistence societies as an imperfect lens for gaining insight. I argue that our evolved human lifespan is about seven decades, and that the multifaceted contributions of middle-to-older aged adults is part of the reason why. I will combine ethnographic, demographic and biomedical studies to shed light on the timing and significance of the transition from "asset" to "burden" in late adulthood, with implications on the global Gray Wave of population aging.