Four experiments investigated the dependence of persuasion on cognitive factors. All experiments employed a court case for which 795 subjects acted as jury members, reading summaries of both the prosecution and defense's testimony. The amount of objective information on both sides of the case was varied. Persuasion was a position function of the number of prosecution arguments and the number of defense arguments. This finding was extended by obtaining measures of the subjects’cognitive reactions to the case as well as their opinions and by following both of these measures over time. Both analysis of variance and multiple regression techniques showed that subjects could have derived their opinions from their cognitions about the case. This relationship also held up over time. These results suggest the general form of an information‐processing theory of persuasion. One prediction of this theory is for an asymptotic function relating objective information to persuasion. This prediction received empirical supp