David L. Hamilton

Illusory Correlation in Interpersonal Perception: A Cognitive Basis of Stereotypic Judgments.

Illusory correlation refers to an erronous inference about the relationship between categories of events. One postulated basis for illusory correlation is the co-occurrence of events which are statistically infrequent; i.e., obserbers overestimate the frequency of co-occurence of distinctive events. If one group of persons “occurs” less frequently than another and one type of behavior occurs infrequently, then the above hypothesis predicts that observers would overestimate the frequency that that type of behavior was performed by members of that group. This suggested that the differential perception of majority and minority groups could result solely from the cognitive mechanisms involved in processing information about stimulus events that differ in their frequencies of co-occurrences. Results of two experiments testing this line of reasoning provided strong supprt for the hypothesis. Implications of the experiments for the acquisition of stereotypes are discussed.

Attribute dimensions and patterns of trait inferences

Rosenberg, Nelson, & Vivekananthan (1968) have suggested that Asch’s (1946) “warm-cold” effect can be meaningfully interpreted within the framework of two dimensions (social and intellectual desirability) which underlie personality impressions. Their analysis suggested that the manipulation of unique information on one dimension would affect trait inferences on that dimension alone. This hypothesis was tested by replicating and extending Asch’s experiment in terms of these two dimensions. The results strongly supported the hypothesis.

Attitudes and Nonattitudes in the Belief Systems of Mass Publics

Summary In opinion polls and experiments on attitude change the assumption is usually made that the respondents and Ss possess relatively stable and meaningful attitudes. Recently, however, this assumption has been the source of considerable controversy. Some theorists, notably Converse, have argued that large portions of the mass public do not have stable and coherent attitudes but, rather, can best be characterized as having “nonattitudes.” To test these contentions, measures of attitudes toward seven current political issues were obtained from two groups of middle-aged men and women respondents who differed in college attendance. Two measures of the attitudes were obtained at a nine- to 11-month interval. Both college (N = 56) and noncollege (N = 59) respondents showed high stability over time in their attitude responses. However, while the college group showed a significant degree of constraint (intercorrelation) among their responses, the noncollege group did not. These results are discussed in terms...