As a foreigner living in San Francisco for the last ten years, I never cease to be baffled by US voters’ tendency to vote for candidates who are clearly class warriors on the side of the rich and other influential special interests. Political scientists have long wondered why people vote against their own best interests, e.g. Americans voting for candidates beholden to health “care” provider lobbies and who hew to the status quo, saddling the US with grotesquely overpriced yet substandard health care. Another example would be the repulsive coddling of an increasingly brazen Wall Street kleptocracy.

Ideology cannot explain it all. Certainly, some people will put principle ahead of their pocketbook and vote for candidates that uphold their idea of moral values even if they simultaneously vote for economic measures that hurt their electorate. That said, there is nothing preventing a political candidate from adopting simultaneously socially conservative positions and economic policies that favor a safety net, what in Europe would be called Christian Democrats.

Media propaganda and brainwashing cannot explain it either, to believe so, as do conspiracy theorists on both right and left of the US political spectrum, is to seriously underestimate the intelligence (and cynicism) of the electorate. In a mostly democratic country like the United States, special interests can only prevail when the general population is apathetic, or at least consents to the status quo.

I believe the answer lies in loss aversion, the mental bias that causes people to fear a loss far more than they desire a gain. Our brains did not evolve in a way that favors strict rationality. Most people’s intuition about probability and statistics is unreliable and misleading—we tend to overestimate the frequency of rare events. The middle class, which holds a majority of votes, will tend to oppose measures that expose it to the risk of being pulled down by lower classes even if the same measures would allow them upward mobility into the upper classes. The upper class exploits this asymmetry to maintain its privileges, be they obscene taxpayer-funded bonuses for bankers who bankrupted their banks, or oligopoly rent-seeking by the medical profession.