Tindale, R. S., Davis, J. H., Vollrath, D. A., Nagao, D. H., & Hinsz, V. B. (1990). Asymmetrical social influence in freely interacting groups: A test of three models. Journal of Personality and Social Psychology, 58, 438-449.
Using freely interacting mock juries, this study tested the predictions of 3 different models of social influence: social impact theory, the other–total ratio, and the social influence model. All 3 models use faction size as the basis for their predictions. On the basis of the predeliberation verdict preferences of 879 female students, groups were composed using all possible nonunanimous verdict compositions (e.g., 5 members for “guilty,” 1 for “not guilty,” etc.) for 3-, 4-, 5-, and 6-person groups. Each group deliberated and reached a group verdict for an attempted murder case, and postdeliberation verdict and probability-of-guilt judgments were obtained from the individual group members. The results showed that faction size affected the relative amount of both majority and minority influence. However, faction size effects differed substantially depending on the verdict supported by the particular faction. Thus, the predictions of even the most accurate model could presumably be improved by modifications allowing for additional interpersonal factors.
Tested 3 formal prediction models for final verdicts. Best model was proportion of initial supporters, but no model did particularly well. Majority influence asymptoted at 3 supporters; 2-person minorities favoring not guilty much more successful than lone dissenters.