Social Discounting and the Prisoner's Dilemma Game

Abstract

Altruistic behavior has been defined in economic terms as “…costly acts that confer economic benefits on other individuals” (Fehr & Fischbacher, 2003). In a prisoner’s dilemma game, cooperation benefits the group but is costly to the individual (relative to defection), yet a significant number of players choose to cooperate. We propose that people do value rewards to others, albeit at a discounted rate (social discounting), in a manner similar to discounting of delayed rewards (delay discounting). Two experiments opposed the personal benefit from defection to the socially discounted benefit to others from cooperation. The benefit to others was determined from a social discount function relating the individual’s subjective value of a reward to another person and the social distance between that individual and the other person. In Experiment 1, the cost of cooperating was held constant while its social benefit was varied in terms of the number of other players, each gaining a fixed, hypothetical amount of money. In Experiment 2, the cost of cooperating was again held constant while the social benefit of cooperating was varied by the hypothetical amount of money earned by a single other player. In both experiments, significantly more participants cooperated when the social benefit was higher.

Dynamically engaged smiling predicts cooperation above and beyond average smiling levels

“…Indeed, closeness among friends has been linked to the amount of money individuals are willing to give up for another person, and to decisions to cooperate in a prisoner's dilemma (Jones & Rachlin, 2006;Locey, Safin, & Rachlin, 2013). To test whether dynamically engaged smiling was an independent signal of cooperative intent, we include a measure of self-reported liking as a covariate in our model.…”

Reciprocation and altruism in social cooperation

“…In prior experiments, Stony Brook students, playing a one-shot 1-2-9-10 PD game (B in Figure 1) with hypothetical rewards and anonymous OP, indeed cooperated at a higher rate than did those playing the 1-2-3-4 PD game (A in Figure 1) (Locey, Safin, & Rachlin, 2013); a corresponding result was found for Stony Brook students playing a face-to-face IPD game with real rewards (Safin et al, 2013). However, Safin et al (2013) found a significant correlation in cooperation rates between partners in the IPD game, which suggests that reciprocation may have played a role in fostering cooperation or defection.…”

Incentivising the Social Discounting Task: A Laboratory Experiment

“…sets, the SDT in some experiments has been employed in tandem with other experimental tasks, including Probability (PDT) and Delay Discounting Tasks (DDT) (in Economics better known as risk and time preference elicitation) (Boyer et al, 2012;Rachlin & Jones, 2008b;Yi et al, 2012;Ziegler & Tunney, 2012) as well as the Prisoner's Dilemma (PD) (Locey, Safin & Rachlin, 2013) and Public Goods Game (PGG) (Jones & Rachlin, 2009 implemented the SDT in a neuro-economics experiment, while Kaplan, Reed and McKerchar (2014) investigate the link of social discounting with experimental choices on environmental loss.…”