The evolutionary psychology of healing: A human success story

Humans are far from being the healthiest of animals. Whether in a modern city or primeval forest, their life-styles expose them to too many risks from infection and accident (a recent study of a group of Paraguayan hunter-gatherers revealed that men are too unwell to hunt 20% of the time [1]). Yet we argue in this essay that humans are by nature exceptionally good — perhaps even the best of all animals — at managing their own recovery when they do fall ill. And this superiority in what we call ‘natural health care’ rests on two special features of human psychology. First, humans are remarkably good at using environmental information to forecast the costs and benefits of deploying their biologicallybased health defenses. Second, they are remarkably susceptible — benignly susceptible as it turns out — to culturally-based ‘medical disinformation’ in the guise of placebo treatments.