The following is an excerpt of the intervention methodology. For more information, please see the full text of the article on the publisher's website or through your institution's library.

Method

Subjects. The subjects were 256 [...] introductory psychology students. Mixed-sex groups of 6 to 10 subjects were run in each session. [...]

Procedure. At the beginning of the experiment, subjects gathered in a single room and were given 5-8 minutes to get acquainted with each other. They were then informed that the purpose of the experiment was to examine the effect of different work conditions on task performance. The first part of the experiment would involve competition. The subjects were then randomly divided into two equal-size groups and told that they would work on two tasks. The groups would be competing with each other, and the group whose performance was judged best by the experimenter would receive extra experimental credit at the end of the session.

At this point, the two groups were segregated into different rooms and given the first task; the groups were required to form a 2-4-sentence jingle [...]. After a 5-10- minute work period, the experimenter introduced the second task: an anagram task [...]. Following the work period, the experimenter returned and requested that subjects complete a questionnaire before beginning the second phase of the study. Subjects were asked to indicate how competitive they felt, how satisfied they were with their own group's performance, and how attracted they were to each of the subjects in the experiment.

For the second phase of the study, all subjects were placed together and told that they would now function as one group. The aim of this phase was to examine the performance of larger groups. The experimenter told the subjects that if their performance was better than a predetermined level, each subject would receive additional experimental credit. [...] At this point the room condition manipulation was exercised. In the ideal-room condition, the experimenter told subjects that the room had been specifically designed to facilitate group task performance [...]. In the poor-room condition, [...] subjects were told that the room might inhibit group performance [...]. In actuality, the room was the same for groups in both conditions.

The first task on which subjects worked was [...] was a human relations problem requiring subjects to assign trucks to five drivers. After they worked on this task for 8 minutes, the experimenter introduced the second task. The second task was an anagram task [...]. [...] The experimenter gathered the results and began comparing the group's performance with the predetermined "target levels". The second manipulation occurred at this point. In half the conditions [...], the experimenter informed the groups that their performance on both tasks had been satisfactory and that they would receive the extra credit. In the fail conditions, the experimenter told subjects that their performance had not reached the acceptable level and she could not give them the extra credit. The succeed-fail manipulation was randomly assigned to groups and was not based on their actual performance.

Following this manipulation, subjects were asked to complete another questionnaire, identical to the one completed after the first phase of the study. Again they rated their mood, evaluated their group's performance, and indicated their attraction to the other subjects. [...]