Ideologists, Non-Ideologists and the Construct Validity of One-Dimensional Measures of Political Ideology

Abstract Previous research has shown that a large part of the population lacks a coherent system of political beliefs (Converse, 1964). Yet, studies in social and political psychology often examine the relationship between ideology and political attitudes/behavior on the basis of a one-dimensional self-placement liberal-conservative or left-right ideology scale that assumes that all of the participants have a coherent ideology. In the current paper we suggest a simple method by which ‘non-ideologists’ could be identified in studies that are based on a one-dimensional ideology scales, and demonstrate that excluding them from the analysis. improves the validity of our conclusions regarding the role of ideology in political psychology. We conclude with a discussion of the pros and the cons of such exclusion.