Abstract
Six five-person and 12 ten-person groups of high school girls were asked to engage in a simple and repetitive task. After a coacting work session (5min. ×5 trials) half of the 10-person groups elected their group leader. Then, all the groups (including other leaderless groups) proceeded to another session with the same task, but this time, in a belt production style. Group norms concerning the production level were measured in terms of Jackson's return potential model before the fist session, between the two sessions and after the second session. Comparison and analysis of these data (together with other data on other variables) revealed: (1) small sized groups maintained their production level relatively constant despite of the technical change, hence stable group norms; (2) of the larger groups, whose production levels proved more liable to the technical impact, leaderless groups showed greater difficulty to reform their group norms, whereas those groups with the elected leader changed the norms in accord with the change in their actual production level.
