Harton, Helen C.

The catastrophe theory of attitudes (Latane & Nowak, 1994) predicts that extremity will be a function of involvement, with uninvolving attitudes normally distributed about a neutral midpoint and involving attitudes categorical and extreme. Two processes that may lead attitudes to become more involving and extreme were tested in this experiment--thought-induced polarization and information-induced polarization. College students rated social issues before and after thinking and/or reading information about them. Attitudes became more extreme after respondents read mixed information about the attitude object, particularly for issues on which participants were initially uninvolved, but did not extremify after thought alone. There was little evidence for selective encoding or retrieval or for biased assimilation, though increases in attitude extremity were associated with increases in involvement. Thus, as predicted by catastrophe theory, reading mixed information may increase involvement in an issue, which in turn leads to more extreme attitudes.

Dynamic social impact theory (DSIT; Latane, 1996a; 1996b), a macro-level theory of social influence, predicts that discussion will lead to a self-organization of public opinion through decreasing minority sizes, increasing spatial similarity, and emerging correlations. The catastrophe theory of attitudes (CTA; Latane & Nowak, 1994), a micro-level theory, suggests that attitudes are a joint function of issue involvement and information favorability. This paper describes the predictions leading from these theories separately and as integrated and meta-analytically combines analyses of almost 500 students discussing social and political issues over a computer network with twenty previous studies testing aspects of CTA. The results of an original computer simulation are also described. Involving attitudes are extreme and change nonlinearly, and involvement mediates thought-, information-, and discussion-induced attitude polarization. Involvement also relates to persuasion and the self-organization of opinion. These studies show converging support for CTA and DSIT and suggest that combining these theories may increase our ability to track the evolution of attitudes from individual beliefs to cultural norms.