For at least fifty years, the rational self-interested agent of neoclassical economics, Homo economicus, has been questioned, rebutted, and in some cases disparaged as a model psychopath. A seminal critique appeared in 1968 with the publication of Garrett Hardin’s article, “The Tragedy of the Commons.” Hardin invited the reader to consider a pasture open to all neighboring herdsman. If those herdsmen pursued their own rational self-interest, he reasoned they would continue to add cows to their herds, ultimately leading to the pasture’s destruction. This has the structure of a multi-player Prisoner’s Dilemma wherein the individual pursuit of rational self-interest inevitably leads to social catastrophe.
Contrary to Homo economicus, people appear to care about more than their own material payoffs. They care about fairness and appear to care about the positive welfare of others. They possess what economists refer to as social preferences. In Dictator games, for example, a person is given some monetary endowment that they can share with an anonymous person. People often transfer some money to the other player. This is so despite the fact that the other player is merely a passive participant and cannot punish them for not transferring some money. Such behavior has been interpreted as evidence for strong reciprocity, a form of altruism on which human cooperation may depend. Emotions emerge at the level of psychological mechanism, such as reported links between empathy and sharing in Dictator games, which mark the distinction between real people and Homo economicus.
As much as we may celebrate the fall of Homo economicus, he would never cut off his nose to spite his face. Far less well-known is recent research probing the darker side of departures from rational self-interest. What emerges is a creature fueled by antisocial preferences, who creates a whole variety of social dilemmas. The common feature of antisocial preferences is a willingness to make others worse off even when it comes at a cost to oneself. Such behaviors are distinct from more prosocial ones, such as altruistic punishment, where me may punish someone for violating social norms. It’s more like basic spite, envy, or malice. An emerging class of economic games, such as money burning games and vendetta games, illustrates the difference. In a basic Joy of Destruction game, for example, two players would be given $10 each and then asked if they want to pay $1 to burn $5 of their partner’s income.
Why would someone pay money to inflict harm on another person who has done nothing against them? The expression and intensity of antisocial preferences appears linked to resource scarcity and competition pressures. Among pastoralists of southern Namibia for example, Sebastian Prediger and colleagues found that 40% of pastoralists from low-yield rangelands burned their partner’s money compared to about 23% of pastoralists from high-yield areas.
Antisocial preferences thus follow an evolutionary logic found across nature and rooted in such rudimentary behaviors as bacteria that release toxins to kill closely-related species: harming behaviors reduce competition and should thus covary with competition intensity. In humans, they underlie such real-world behaviors as the rate of “witch” murders in rural Tanzania. As Edward Miguel found there, these murders double during periods of crop failure. The so-called witches are typically elderly women killed by relatives, who are both blamed for causing crop failure and whose death as the most unproductive members of a household helps alleviate economic hardship in times of extremely scarce resources.
Why should the concept of antisocial preferences be more widely-known and used in the general culture? I think there are two main reasons. Although we still tend to blame Homo economicus for many social dilemmas, many are better explained by antisocial preferences. Consider, for example, attitudes toward income redistribution. If these were based on rational self-interest, anyone earning less than mean income should favor redistribution since they stand to benefit from that policy. Since income inequality skews income distribution rightward, with increasing inequality a larger share of the population has income below the mean and so support for redistribution should rise. Yet, empirically this is not the case. One reason is antisocial preferences. As Ilyana Kuziemko and colleagues found, people exhibit “last place aversion” both in the lab and in everyday social contexts. That is, individuals near the bottom of the income distribution oppose redistribution because they fear it might result in people below them either catching up to them or overtaking them, leaving them at the bottom of the status hierarchy.
The second reason why antisocial preferences should be more widely known has to do with long-run trends in resource scarcity and competition pressures. A nearly 40-year trend of broad-based wage stagnation and projections of anemic long-term economic growth mean increasing resource scarcity and competition pressures for the foreseeable future. As a result, we should expect antisocial preferences to increasingly dominate prosocial ones as primary social attitudes. In the United States, for example, the poorest and unhealthiest states are the ones most opposed to Federal programs aimed at helping the poorest and unhealthiest. We can only make sense of such apparent paradoxical human behavior by a broader understanding of the irrational, spiteful and self-destructive behaviors rooted in antisocial preferences and the contexts that trigger them.