Social Desirability Bias in Measures of Partisanship

Scholars have long suggested that as a particular view or perspective becomes the social norm, we run the risk of overestimating the prevalence of this perspective due to social desirability bias. In this manuscript we address this possibility of this effect in one of the most fundamental measures in American politics: the measure of partisanship. In particular, we argue that social desirability pressures may lead individuals to misrepresent their partisan affiliations, and instead report that they are independent. Further, we suggest that this tendency to eschew partisanship is most likely to happen when individuals are reminded of elite partisan disagreement and can be further exacerbated by question-wording in measures of partisanship. We make our case through two survey experiments. The first study traces the presence of social desirability in measures of partisanship and shows that individuals believe that identifying as an independent makes a better impression. This effect is particularly likely when individuals are reminded of partisan disagreement. The second study relies on a national sample and considers this social desirability effect under different lead-ins to the partisanship question. At a time when surveys show record rates of individuals identifying as independent, our results have critical implications for the way scholars measure partisanship, particularly during points when elite partisan disagreement is highly prevalent. As a particular perspective becomes the social norm, we run a risk of overestimating public opinion due to social desirability bias (Berinsky 2002). Psychological (Schlenker and Weingold 1989) and sociological (Goffman 1959) theories of self-construction suggest that individuals aim to portray themselves in such a manner that will be pleasing to others (Holbrook and Krosnick 2010). When asked matters of opinion, we are thus susceptible to answering in a manner that will be most pleasing – and least controversial – for the sake of optimal selfpresentation (Presser 1990). Indeed, social desirability repeatedly proves itself as a persistent obstacle for measuring opinions and behaviors (Belli et al. 2001; Karp and Brockington 2005; Streb et al 2008; Tourangeau and Yan 2007). In this study, we consider the potential for social desirability bias in the measurement of one of the most fundamental questions in American politics: partisanship. The origins of partisanship are subject to considerable debate, with some arguing that it is the sum of a running tally of political evaluations (Bartels 2002), others demonstrating that it is a social identity group (Green et al. 2002), and still others pointing to ideological roots (Abramowitz and Saunders 1998). All agree, however, that partisanship is influential, persistent, and resistant to change (Campbell et al. 1960, p. 146). It is not our goal to cast doubt on the stability of partisanship, but rather we examine the potential for social desirability bias in measurement of partisan affiliation. We argue that certain categories of partisanship may be viewed as particularly socially desirable, thus introducing social desirability bias into this measurement. Specifically, we argue and show that political independence is viewed as an aspirational ideal. With an experimental study, we demonstrate that this effect is exacerbated by exposure to partisan disagreement. Furthermore, we find that certain forms of survey question wording play a key role in stimulating social desirability bias. The Social Desirability of Independence Why might political independence be viewed as socially desirable? The effect lies in political context. In recent decades, negative political news coverage has nearly tripled (Patterson 2010) and evidence suggests that we have reached a point of unprecedented vitriol in politics (Wagner et al. 2011). In particular, American media casts partisan politics with a disproportionately negative light (e.g. Patterson 1994; Lichter and Noyes 1997; Hallin and Mancini 2004). Even if people avoid news coverage all-together, they are often exposed to disagreement incidentally via Internet discussion (Wojcieszak and Mutz 2009). In turn, media coverage often has significant influence over people’s political priorities and impressions (Zaller 1992; Bartels 1993). McQuail (1979) explains: “We can expect the mass media to tell us about different kinds of social roles and the accompanying expectations ..." (p. 14). Taken together, negative coverage of politics, and in particular partisan politics, can lead individuals to view partisan identification as socially undesirable, motivating them to shy away from reporting an allegiance to a party and instead opting toward a politically “independent” category (self-categorizing as either a “pure” or “leaning” independent). We do not suggest exposure to partisan disagreement will necessarily weaken actual party identification – though it may do that for certain individuals –rather we suggest that exposure to partisan disagreement sullies the perceived desirability of partisanship.