Over the course of competition, the groups became increasingly hostile to each other. What started as good sportsmanship escalated to quickly to name calling, cheating, raiding of cabins, and fistfights. Some of the boys carried around rocks in their socks as protection in case they were ambushed by the other team. As Sherif noted in his 1966 book Group Conflict and Co-operation, competition generally led to “us versus them” group identities. Through this experiment, boys with no behavioural issues were turned into hostile, narrow-minded opponents.60
