Publication Date


Document Type


First Advisor

Kaplan, Martin F.

Degree Name

M.A. (Master of Arts)

Legacy Department

Department of Psychology


Information theory in psychology


It was hypothesized that breadth of information is an antecedent of both response extremity and requests for further information in social perception. By demonstrating the existence of common factors mediating both behaviors (i.e., breadth of information and consequent subjective certainty), it would be possible to consider these heretofore unrelated behaviors within a common theoretical framework. Predictions followed from a confluence of information integration theory and attribution theory, allowing a test of a theoretical framework combining these complementary theories. One hundred and twenty-eight undergraduates received information about fictitious foreign countries which varied in evaluative level (positive or negative), range of informational categories (1 or 4), and number of expert sources (1 or 4). For each country, subjects judged the attractiveness of the country, then rated their confidence in that judgment, and finally, Indicated how much more information they would need to reach an optimal judgment if asked to re-evaluate the country. It was hypothesized that judgments would be more extreme, subjective certainty would be greater, and amount of information sought would be less when information was negative, or represented a broad range of categories, or was attributed to a greater number of sources. Results fully agreed with predictions regarding stimulus valence, and more importantly, the variety factor. Varied information led to more extreme attractiveness response, greater confidence, and less information requested. Thus, an important linkage is established between social perception and information search, and the role of confidence as a mediator of such responses is suggested. Number of sources was found to be a determinant of information request, in accord with attribution theory. Contrary to predictions, however, number of sources was not found to be important for response extremity. This was attributed, in part, to the fact that sources were identified as exports, so that a high degree of confidence was already accorded even one source. Theoretical considerations suggest the combination of information integration and attribution theories as a conceptual basis for social perception and information search. Information integration theory deals with the combination of information in judgment, and attribution theory suggests the manner in which information is weighted as a function of its informativeness. Finally, a model analysis is proposed regarding the combination of information weights from several weighting sources.


Includes bibliographical references (pages [48]-53)


67 pages




Northern Illinois University

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