Subjects 

Forty-eight female introductory psychology students were randomly selected from a pool of voluntary Ss.

Six Ss were scheduled for each of eight experimental sessions, during which they were divided into two three-person groups.

Procedure and Design 

In every session Ss were informed about the aim of the project [...]

The information was worded neutrally without mentioning bias or fairness.

[...] Ss were divided into Groups A and B by drawing lots and were identified by code numbers to ensure anonymity. They then worked individually on a word-generating task [...]

When announcing the amount of reward available for allocation, the E stressed that both groups had contributed more or less equally to it.

Prediscussion phase 

Each S received an allocation pamphlet on which she would indicate her division of the reward between two other Ss. The pamphlet contained information about the relative word scores of the two recipients: One recipient either had a “higher” or “lower” word score than the other. No mention was made of the S’s own score. The recipients’ group membership was varied to produce one intragroup and two intergroup conditions.

Each S indicated privately on the pamphlet her allocation decision.

Ss were told that their decisions would remain anonymous and were unrelated to how much they would receive themselves.

[...] each S indicated on a five-point scale how confident she was about making the decision.

Discussion phase 

Members of the two groups, A and B, were seated separately in two rooms. Each group was then assigned a hypothetical case of dividing the reward between an (unidentified) ingroup recipient and an outgroup recipient.

Discussion began, as directed, with each S stating publicly her preferred allocation. This was followed by a free-discussion period of up to 15 minutes.

The E and his assistant observed but did not participate in the discussion [...]

Postdiscussion phase 

Each S was asked to reexamine her prediscussion private allocation decision with the instruction

After the group discussion, you may or may not wish to change the way you previously divided the papers.

She then completed the allocation and confidence questions again in the same manner as before.