Showing that you care: The evolution of health altruism

Summary 

Human behavior regarding medicine seems strange; assumptions and models that seem workable in other areas seem less so in medicine. Perhaps, we need to rethink the basics. Toward this end, I have collected many puzzling stylized facts about behavior regarding medicine, and have sought a small number of simple assumptions which might together account for as many puzzles as possible.

The puzzles I consider include a willingness to provide more medical than other assistance to associates, a desire to be seen as so providing, support for nation, firm, or family provided medical care, placebo benefits of medicine, a small average health value of additional medical spending relative to other health influences, more interest in public that private signals of medical quality, medical spending as an individual necessity but national luxury, a strong stress-mediated health status correlation, and support for regulating health behaviors of the low status. These phenomena seem widespread across time and cultures.

I can explain these puzzles moderately well by assuming that humans evolved deep medical habits long ago in an environment where people gained higher status by having more allies, honestly cared about those who remained allies, were unsure who would remain allies, wanted to seem reliable allies, inferred such reliability in part based on who helped who with health crises, tended to suffer more crises requiring non-health investments when having fewer allies, and invested more in cementing allies in good times in order to rely more on them in hard times.

These ancient habits would induce modern humans to treat medical care as a way to show that you care. Medical care provided by our allies would reassure us of their concern, and allies would want you and other allies to see that they had pay enough to distinguish themselves from posers who didn’t care as much as they. Private information about medical quality is mostly irrelevant to this signaling process.

If people with fewer allies are less likely to remain our allies, and if we care about them mainly assuming they remain our allies, then we want them to invest more in health than they would choose for themselves. This tempts us to regulate their health behaviors. This analysis suggests that the future will continue to see robust desires for health behavior regulation and for communal medical care and spending increases as a fraction of income, all regardless of the health effects of these choices.