Showing papers by "Michael W. Macy published in 1999"

Structural Learning: Attraction and Conformity in Task-Oriented Groups

Abstract: This study extends previous research that showed how informal social sanctions can backfire when members prefer friendship over enforcement of group norms. We use a type of neural network to model the coordination of informal social control in a small group of adaptive agents confronted with a social dilemma. This model incorporates two mechanisms of social influence, informal sanctions and imitation. Both mechanisms vary with the strength of the social tie between source and target. Previous research focused on the effects of social sanctions. Here, we demonstrate a curvilinear effect of imitation on compliance with prosocial norms. Moderate doses of imitation reduce the coordination complexity of self-organized collective action and help the network achieve satisfactory levels of cooperation. High doses, however, undermine the agent-based learning required to find cooperative solutions. Increasing group size also diminishes compliance due to increased complexity, with larger groups requiring more imitation to overcome the coordination problem.

Unlocking the doors of the Prisoner's dilemma : Dependence, selectivity, and cooperation

Abstract: desired partner. This suggests that an exit option increases cooperation. We tested both hypotheses in laboratory experiments with human subjects, using "Trump," a new cardgame representation of a Prisoner's Dilemma. In the first experiment, the exit option reduced dependence and increased selectivity, relative to a no-exit condition. We found that selectivity and dependence both increased cooperation, but for different reasons and with different players, leaving overall cooperation rates unchanged by an option to exit. In a second experiment, the exit option increased selectivity but not dependence, relative to a forced-exit condition. Here we observed higher cooperation with an option to exit, but only for subjects playing defensive strategies.

"in search of excellence": fads, success stories, and communication bias.

Abstract: The faddishness of the business community is often noted and lamented, but not well comprehended by standard models of innovation and diffusion. We develop a model of innovation adoption and abando...