From a review of the available literature related to persuasive communication, the author proposes a mathematical model of attitude change in human groups satisfying a set of premises concerning the following variables: discrepancy, source credibility, ego involvement, plausibility, distraction, and effort. This model is shown to be consistent with cognitive dissonance theory, the social judgment‐involvement approach, learning theory, and to provide links with perception.
After determining the proper estimating procedure, the model was extensively tested with more than 50 sets of published data. The instrument used was regression analysis. It appears to be well supported by the available data. Nevertheless, more effort is necessary to introduce other variables, including time, to incorporate the boomerang effect and to solve the problem of infinite horizon on the attitude scale. It is suggested that this model has relevance to individual as well as group behavior.