The Nature of Party Categories in Two-Party and Multiparty Systems

Categories are one of the primary ways by which people make sense of complex environments. For political environments, parties are especially useful categories. By simplifying political life, party categories enable people to make sense of politics. A fundamental characteristic of party categories is that they minimize perceived differences of members within a party (e.g., two Democrats) and maximize perceived differences between members of different parties (e.g., a Republican and a Democrat). In two-party systems, politicians in leftist parties will often be perceived as highly differentiated from politicians in right-wing parties. Yet, in multiparty systems there is greater complexity and potential for confusion since there are often multiple parties on the left and/or right. Spatial models of political competition predict that ideologically close neighboring parties will be perceived as similar, yet a categorical perspective holds that the public will perceive parties on the same side of the ideological divide to be dissimilar. In the present article, we review a research program investigating how political parties are treated as categories and present new data from seven democracies showing that people perceive parties to be highly differentiated regardless of where parties are located in ideological space.