Abstract: Under small world network structure, this research constructed a contagion model of cooperative behavior based on behavioral characteristics such as homogeneity gathering, two degrees of separation, influence paradox, attenuation nature, etc. and used Netlogo platform to run the simulation. The results indicate the contagion of cooperative behavior has hysteresis, emergent and progressive properties; the average path length constrains the contagion completion; the strong ties are prone to spread cooperative behavior; the distribution level of node degree of network significantly impacts the contagion time. The discoveries afford guidance for enhancing cooperation performance in small groups, by adjusting relationship links among members, shortening average path, strengthening critical relationship ties, and fostering the cooperative behavior emergence and the systematic cooperative characteristics.

Key words: behavior contagion, small world network, cooperative behavior, simulation model