Oleg Smirnov

On the Evolutionary Origin of Prospect Theory Preferences

Prospect theory scholars have identified important human decision-making biases, but they have been conspicuously silent on the question of the origin of these biases. Here we create a model that shows preferences consistent with prospect theory may have an origin in evolutionary psychology. Specifically, we derive a model from risk-sensitive optimal foraging theory to generate an explanation for the origin and function of context-dependent risk aversion and risk-seeking behavior. Although this model suggests that human cognitive architecture evolved to solve particular adaptive problems related to finding sufficient food resources to survive, we argue that this same architecture persists and is utilized in other survival-related decisions that are critical to understanding political outcomes. In particular, we identify important departures from standard results when we incorporate prospect theory into theories of spatial voting and legislator behavior, international bargaining and conflict, and economic development and reform.

Egalitarian motive and altruistic punishment

Arising from: E. Fehr & S. Gächter 415, 137–140 (2002); E. Fehr & S. Gächter replyAltruistic punishment is a behaviour in which individuals punish others at a cost to themselves in order to provide a public good. Fehr and Gächter present experimental evidence in humans indicating that negative emotions towards non-cooperators motivate punishment, which, in turn, provokes a high degree of cooperation. Using Fehr and Gächters original data, we provide an alternative analysis of their experiment that suggests that egalitarian motives are more important than motives for punishing non-cooperative behaviour. This finding is consistent with evidence that humans may have an evolutionary incentive to punish the highest earners in order to promote equality, rather than cooperation.

Human behaviour: Egalitarian motive and altruistic punishment

Fehr and Gächter reply - Fowler et al. raise an important question. They correctly argue that the desire to reduce inequality may motivate cooperators who altruistically punish free riders in our experiments. Also, the evolutionary history of humans suggests that egalitarianism shaped many human cultures and that egalitarian motives may, therefore, be a powerful force behind the punishment of free riders. In addition, recently developed proximate theories, which formalize the notion of inequality aversion, also suggest that egalitarian desires may be important. Fowler et al. contrast their egalitarianism hypothesis with our view that negative emotions against free riders drive punishment.

Ancestral War and the Evolutionary Origins of Heroism

Primatological and archeological evidence along with anthropological accounts of hunter-gatherer societies indicate that lethal between-group violence may have been sufficiently frequent during our ancestral past to have shaped our evolved behavioral repertoire. Two simulations explore the possibility that heroism (risking ones life fighting for the group) evolved as a specialized form of altruism in response to war. We show that war selects strongly for heroism but only weakly for a domain-general altruistic propensity that promotes both heroism and other privately costly, group-benefiting behaviors. A complementary analytical model shows that domain-specific heroism should evolve more readily when groups are small and mortality in defeated groups is high, features that are plausibly characteristic of our collective ancestral past.

Policy-Motivated Parties in Dynamic Political Competition

We analyze a model of a dynamic political competition between two policy-motivated parties under uncertainty. The model suggests that electoral mandates matter: increasing the margin of victory in the previous election causes both parties to shift towards policies preferred by the winner, and the loser typically shifts more than the winner. The model also provides potential answers to a number of empirical puzzles in the field of electoral politics. In particular, we provide possible explanations for why close elections may lead to extreme platforms by both parties, why increased extremism in the platform of one party may lead to greater moderation in the platform of the other party, and why increasing polarization of the electorate causes winning candidates to become more sensitive to mandates. We also show that, contrary to previous findings, increasing uncertainty sometimes decreases platform divergence. Finally, we pay special attention to the proper methodology for doing numerical comparative statics analysis in computational models.

Dynamic Parties and Social Turnout: An Agent-Based Model

The authors develop an agent‐based model of dynamic parties with social turnout built upon developments in different fields within social science. This model yields significant turnout, divergent platforms, and numerous results consistent with the rational calculus of voting model and the empirical literature on social turnout. In a simplified version of the model, the authors show how a local imitation structure inherently yields dynamics that encourage positive turnout. The model also generates new hypotheses about the importance of social networks and citizen‐party interactions.

Altruistic Punishment in Politics and Life Sciences: Climbing the Same Mountain in Theory and Practice

As reflected in theory, laboratory evidence, and field studies, altruistic punishment of defectors promotes cooperation. Costly self enforcement of socially optimal behavior has a number of independent links in political science, economics, psychology, sociology, computer science, and biology. This paper integrates the study of sanctions-based provision of public goods in the social sciences with the research on evolutionary adaptedness of altruistic punishment in the life sciences. Altruistic punishment appears to be (1) economically rational, (2) evolutionarily robust as an individual propensity and as a cultural norm, (3) normatively more appealing than tit-for-tat, which is a reciprocal punishment by defection, and (4) socially common. The theoretical and empirical importance of altruistic punishment has immediate policy implications. Examination of commons around the world suggests that privatization and centralized coercion are not the only solutions to the tragedy of the commons. A viable policy alternative is to facilitate the evolution of the commons as a common-property regime with its own norms and a certain degree of independence.

An alternative mechanism through which economic inequality facilitates collective action: Wealth disparities as a sign of cooperativeness

Past models treat economic inequality as an exogenous condition that can provide individuals a dominant incentive to produce collective goods unilaterally. Here we part with that tradition so as to treat economic inequality and collective action as endogenous, and to examine whether economic inequality can foster collective action even when all individuals can gain from free-riding. Using evolutionary game theory and computer simulations, we study whether cooperation can evolve when agents play multiple, one-shot prisoner’s dilemma (PD) games per generation and employ strategies that condition cooperative play on their game partners’ wealth holdings. In this game environment, we find that collective action succeeds via a strategy in which players choose to cooperate when joining a PD with an economic equal and defect when partnered with a player possessing wealth holdings unequal to their own. These results signal an alternative avenue through which economic inequality can influence the viability of collective action.

Passive non-participation versus strategic defection in a collective risk social dilemma

Empirical evidence suggests that non-participation underlies a variety of social dilemmas. In collective risk social dilemmas (CRSD), non-participation is viewed as strategic defection—a selfish behavior that increases individual utility at the cost of the group. We conducted a hybrid laboratory-then-online experiment to examine if non-participation in a CRSD may be fundamentally different from the act of strategic defection. We confirmed that non-participation is a problem in a social dilemma. When participation is required, a randomly formed group of subjects was virtually certain to reach the loss prevention threshold (0.999 probability). On the other hand, when an empirically realistic non-participation option was introduced, the probability of reaching the goal by a randomly formed group decreased to 0.599. We also found evidence that the profile of a typical non-participant does not fit the profile of a strategic defector. Non-participants in the experiment were highly cooperative when they had to make a contribution decision. Non-participants in the experiment did not try to increase their payoffs, including in the treatment condition when non-participation led to a default contribution of 100% of the subject’s endowment.

Inequality as information: Wealth homophily facilitates the evolution of cooperation

Free-riding produces inequality in the prisoners’ dilemma: cooperators suffer costs that defectors avoid, thus putting them at a material disadvantage to their anti-social peers. This inequality, accordingly, conveys information about a social partner’s choices in past game play and raises the possibility that agents can use the aggregation of past payoffs—i.e. wealth—to identify a social partner who uses their same strategy. Building on these insights, we study a computational model in which agents can employ a strategy—when playing multiple one-shot prisoners’ dilemma games per generation—in which they view other agents’ summed payoffs from previous games, choose to enter a PD game with the agent whose summed payoffs most-closely approximate their own, and then always cooperate. Here we show that this strategy of wealth homophily—labelled COEQUALS (“CO-operate with EQUALS”)—can both invade an incumbent population of defectors and resist invasion. The strategy succeeds because wealth homophily leads agents to direct cooperation disproportionately toward others of their own type—a phenomenon known as “positive assortment”. These findings illuminate empirical evidence indicating that viewable inequality degrades cooperation and they show how a standard feature of evolutionary game models—viz. the aggregation of payoffs during a generation—can double as an information mechanism that facilitates positive assortment.