An account read by Lukas describes an experiment at Robber Cave in which divisions between two groups of boys escalated into uncontrollable violence.
The account Lukas reads describes experimenters posing as camp counselors at Robber Cave. Two groups of boys with similar backgrounds and values developed divisions between their own group and the other group.
According to the account, small differences in clothing and speech became reasons for hostility. The experiment ended early because the violence became uncontrollable.
It is an experiment described in Lukas’s historical reading, tracing hostility between groups of otherwise similar boys.