Today's post, The Robbers Cave Experiment was originally published on 10 December 2007. A summary (taken from the LW wiki):

The Robbers Cave Experiment, by Sherif, Harvey, White, Hood, and Sherif (1954/1961), was designed to investigate the causes and remedies of problems between groups. Twenty-two middle school aged boys were divided into two groups and placed in a summer camp. From the first time the groups learned of each other's existence, a brutal rivalry was started. The only way the counselors managed to bring the groups together was by giving the two groups a common enemy. Any resemblance to modern politics is just your imagination.

Discuss the post here (rather than in the comments to the original post).

This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was When None Dare Urge Restraint, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.

Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.