Direct and indirect effect of punishment

Human cooperation in a large group of genetically unrelated people is an evolutionary puzzle. Despite its costly nature, cooperative behaviour is commonly found in all human societies, a fact that has interested researchers from a wide range of disciplines including biology, economics, and psychology to name a few. Many behavioural experiments have demonstrated that cooperation within a group can be sustained when free riders are punished. We argue that punishment has both a direct and an indirect effect in promoting cooperation. The direct effect of punishment alters the consequences of cooperation and defection in such a way as to make a rational person prefer cooperation. The indirect effect of punishment promotes cooperation among conditional cooperators by providing the condition necessary for their cooperation -- i.e., the expectation that other members will also cooperate. Here we present data from two one-shot, n-person Prisoner's Dilemma games, demonstrating that the indirect effect of punishment complements the direct effect to increase cooperation in the game. Further, we show that the direct and indirect effects are robust across two forms of punishment technology; either when the punishment is voluntarily provided by game players themselves or when it is exogenously provided by the experimenter

Physical attractiveness and cooperation in a prisoner's dilemma game

The modulating role of age on the relationship between physical attractiveness and cooperativeness in a prisoner's dilemma game (PDG) was investigated. Previous studies have shown that physical attractiveness is negatively related to cooperative choices among young men but not young women. Following the argument that the negative relationship between physical attractiveness and cooperation is a product of short-term mating strategies among attractive men, we predicted that this relationship is unique to young men and absent among women and older men. We tested this hypothesis with 175 participants (aged 22-69 years). The results showed that physical attractiveness was negatively related to cooperative behavior among young men but not among women or older men. We further observed that the negative relationship between physical attractiveness and cooperation among young men was particularly strong when attractiveness was judged by women. © 2014 Elsevier Inc. All rights reserved. Physical attractiveness, particularly facial attractiveness, invites favorable responses from other individuals. People tend to perceive that physically attractive individuals possess desirable personal traits, such as intelligence and benevolence. This perception is referred to as the "what is beautiful is good" stereotype, which is an example of the more general halo effect studied in social psychology Is this belief true? Empirical studies of women have revealed that attractiveness does not correlate with desirable inner traits Physical attractiveness and cooperation Why is physical attractiveness unrelated or negatively related to the behavioral cooperativeness exhibited in the aforementioned experiments? Fitness-related evolutionary theories explain these results from the logic of mate selectio

False friends are worse than bitter enemies: bAltruisticQ punishment of in-group members

Abstract One of the most critical features of human society is the pervasiveness of cooperation in social and economic exchanges. Moreover, social scientists have found overwhelming evidence that such cooperative behavior is likely to be directed toward in-group members. We propose that the groupbased nature of cooperation includes punishment behavior. Punishment behavior is used to maintain cooperation within systems of social exchange and, thus, is directed towards members of an exchange system. Because social exchanges often take place within groups, we predict that punishment behavior is used to maintain cooperation in the punisher's group. Specifically, punishment behavior is directed toward in-group members who are found to be noncooperators. To examine this, we conducted a giftgiving game experiment with third-party punishment. The results of the experiment (N = 90) support the following hypothesis: Participants who are cooperative in a gift-giving game punish noncooperative in-group members more severely than they punish noncooperative out-group members

Running Head: Cultural transmission and human adaptability

It is often taken for granted that social/cultural learning increases human adaptability, because it allows us to acquire useful information without costly individual learning by trial and error. Rogers (1988) challenged this common view by a simple analytic model. Assuming a “cultural ” population composed of individual learners engaging in costly information search and imitators who just copy another member’s behavior, Rogers showed that mean fitness of such a mixed “cultural ” population at the evolutionary equilibrium is exactly identical to the mean fitness of an “acultural ” population consisting only of individual learners. Rogers ’ result implies that no special adaptive advantage accrues from social/cultural learning. We revisited this counter-intuitive argument through use of an experiment with human subjects, and by a series of evolutionary computer simulations that extended Kameda & Nakanishi (2002). The simulation results indicated that, if agents can switch the individual learning and imitation selectively, a "cultural " population indeed outperforms an "acultural " population in mean fitness for a broad range of parameters. An experiment that implemented a non-stationary uncertain environment in a laboratory setting provided empirical support for this thesis. Implications of these findings for cultural capacities and some future directions are discussed. Key Words: social learning, cultural transmission, non-stationary uncertain environment, mean fitness, producer-scrounger dilemm