Cooperation in a three-person Prisoner's Dilemma.

Abstract

Subjects played either a standard two-person Prisoner's Dilemma game or an equivalent three-person version. Despite the fact that an economic model would predict equal rates of cooperation, triads were substantially less cooperative. The transition matrices indicated that it was more difficult in the threeperson setting to establish a pattern of cooperation that could be subsequently maintained.

The effect of social motives, communication and group size on behaviour in an N‐person multi‐stage mixed‐motive game

“…Hence, in larger groups persons should feel less constraint against behaving in a self-interested way for the short term. Prior studies assessing the effect of group size indeed do report somewhat less cooperation in larger groups (Bixenstine et al, 1966;Bonacich, Shure, Kahan and Meeker, 1976;Hamburger, Guyer and Fox, 1975;Komorita and Lapworth, 1982;Marwell and Schmidt, 1972). However, in these studies the range of group size is relatively small (up to nine persons).…”

Cooperation in small groups: the effect of group size

“…One is based on the idea that a number of factors conducive to cooperation, such as social pressure and social incentives, may be more effective in small than larger groups (Olson 1965). Other authors (Marwell and Schmitt 1972) have suggested the 'bad apple' hypothesis. Many individuals are willing to cooperate, but only as long as others do so as well.…”

“…See Ledyard (1995) and Chaudhuri (2011) for reviews of experiments using this framework. 2 Marwell and Schmitt (1972) compare two-and three-person prisoner's dilemma games, while Bonacich et al (1976) study three-, six-and nine-person games. In both studies payoff matrices are chosen so that cooperating rather than defecting decreases own payoff, and increases total payoff, by the same amount across games.…”

“…For example, Marwell and Schmitt (1972) and Bonacich et al (1976) study n-person iterated prisoner's dilemmas where they vary n while keeping constant the private and social costs and benefits of cooperating. 2 They find that cooperation rates are lower in larger groups.…”

Explaining international voluntary cooperation under anarchy: an analysis of emergent norm governed behavior as substitute for a global sovereign

“…On the positive side, it was noted that the &ee rider hypothesis tends to be supported as group size increases (Dawes et al, 1977;Marwell and Schmidt, 1972).…”