Group Cohesion,Task Performance,and the Experimenter Expectancy Effect

Abstract

Three laboratory experiments were done to study the effects of cohesion on task fulfillment and to explore the influence of task fulfillment on the initial level of cohesion. Within four-person groups of freshmen psychology students, cohesion was manipulated successfully by a triple procedure. The level of cohesion was ascertained directly after the induction treatment and again after task fulfillment. Group and individual ability tasks were used in the first and second experiment, while individual learning tasks were used in the third experiment. The hypothesis that cohesion facilitates task performance was partly supported for both individual and group tasks. All eight comparisons of the means favoured the high-cohesion condition; only four of the differences, however, were statistically significant. Performing a group task tended to raise cohesion, whereas individual task performance lowered liking for the group. There were no indications that the findings were a function of a pretest effect of the cohesion questionnaire or the experimenter's awareness of the research hypotheses. The facilitating influence of cohesion on task fulfillment was considered a consequence of heightened drive level of group members.