The Norm Knockout Method (IMAGE) Rissho University Caption The norm knockout method reveals that cooperative behavior does not arise in a society where the norm indicated by the red line [SH] and the norm indicated by the light blue line [IS] do not exist. Credit Hitoshi Yamamoto, Ph.D. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.