Self-questioning games and ping-pong effect in the BA network

In this paper, we study the evolutionary Prisoner’s Dilemma Game (PDG) and the Snowdrift Game (SG) with a selfquestioning updating mechanism in the Barabási–Albert (BA) network. Although this self-questioning mechanism does not show much advantages in sustaining the cooperative behavior comparing to the existing models, it can produce interesting non-monotonic phenomena in numerical simulations. Furthermore, this new model has avoided the system from being enmeshed in a globally defective trap, which is a shortcoming of the existing models based on the learning mechanisms. It is found that in certain cases, the so called ‘‘Cooperative Ping-pong Effect’’ occurs in both the two games and plays an important role in the behaviors of the whole system. This new model shows non-trivial characters comparing to the previous work and is worthy of further studies. r 2007 Elsevier B.V. All rights reserved.