Kerr, N. L. (1981). Social transition schemes: Charting the group’s road to agreement. Journal of Personality and Social Psychology, 41, 684-702.
Outlines a stochastic model of the group decision-making process: the social transition scheme model. Two key assumptions are identified: (1) The path-independence assumption holds that where the group goes next depends on its current state but not on how it reached that state, and (2) the stationarity assumption holds that the likelihood of any particular movement toward consensus does not depend on how long the group has been deliberating. The deliberations of mock juries were analyzed to see whether the process was path independent and stationary; 126 female and 156 male undergraduates were Ss. In addition, the effects of group experience, member sex, and deliberation time limits in the decision-making process were examined. Results show that the process was path dependent and nonstationary. The path dependence reflected a momentum effect: Groups tended to continue in the direction in which they had just moved. However, incorrectly assuming path independence and stationarity had little effect on the predictive accuracy of the model. Group experience speeded up movement when the group was sharply divided. Member sex and time limitations had no effect on the decision process. The relevance of the latter result for simulation research on juries is discussed.
No impact of jury sex or experience on preference shifts. Shifts in preference distribution a function of majority, leniency, and momentum effects. Juries tended to move toward verdict favored by majority (especially in second half), toward acquittal, and in the same direction as the previous shift. Shifts occurred faster as juries neared consensus. First shift better predictor than predeliberation preference distribution.