Showing papers by "Michael W. Macy published in 1996"

The weakness of strong ties: Collective action failure in a highly cohesive group*

Abstract: Following Homans, exchange theorists have modeled informal social control as an exchange of peer approval for compliance with group obligations. The exchange model predicts higher compliance in cohesive networks with strong social ties. However, previous specifications failed to incorporate bilateral exchange of approval. Computer simulations using a Bush‐Mosteller stochastic learning model show that bilateral exchanges evolve more readily than multilateral, causing social control to flow into the maintenance of interpersonal relationships at the expense of compliance with group obligations, a structural form of the “second‐order free‐rider problem.”

Natural Selection and Social Learning in Prisoner's Dilemma: Coadaptation with Genetic Algorithms and Artificial Neural Networks

Abstract: Evolutionary game theory has been used to study the viability of cooperation in a predatory world. While previous studies have helped to identify robust strategies, little is known about how success translates into the reproduction of cultural rules. Analogs of genetic replication may be deceptive if social learning and natural selection engender different population dynamics. I distinguished selection and learning based on whether rules are hardwired or softwired in the organisms that carry them. I then used genetic algorithms and artificial neural networks to operationalize the distinction. Applied for the first time to iterated Prisoner’s Dilemma, neural network experiments showed that researchers may need to be much more cautious in using Darwinian analogs as templates for modeling the evolution of cultural rules.