学术报告

报告题目：Social cycling and conditional responses in the Rock-Paper-Scissorsgame  
报告人： 周海军

               中国科学院理论物理研究所，研究员

报告时间：2014年5月20日（星期二）下午13:00-14:00

地点：北京大学定量生物学中心老化学楼东配楼102会议室（理教路西/光华楼北侧） 

摘要：

 How humans make decisions in non-cooperative strategic interactionsis a challenging question. For the fundamental model system ofRock-Paper-Scissors (RPS) game, classic game theory of infinite rationalitypredicts the Nash equilibrium (NE) state with every player randomizing herchoices to avoid being exploited, while evolutionary game theory of boundedrationality in general predicts persistent cyclic motions, especially for finitepopulations. However, as empirical studies on human subjects have beenrelatively sparse, it is still a controversial issue as to which theoreticalframework is more appropriate to describe decision making of human subjects.Here we observe population-level cyclic motions in a laboratory experiment ofthe discrete-time iterated RPS game under the traditional randompairwise-matching protocol.The cycling direction and frequency are not sensitiveto the payoff parameter a. This collective behavior contradicts with the NEtheory but it is quantitatively explained by a microscopic model of win-lose-tieconditional response without any adjustable parameter. Our theoreticalcalculations reveal that this new strategy may offer higher payoffs toindividual players in comparison with the NEmixed strategy, suggesting that highsocial efficiency is achievable through optimized conditionalresponse.

主持人：汤超教授