Are There Ideological Differences in Intergroup Bias? Examining Liberal-Conservative (A)symmetries in Minimal Group Cognition and Behavior

The liberal-conservative divide is one of the most contentious divisions in modern society. Several influential theoretical perspectives contend that this divide hinges primarily on orientations towards social groups, such that conservatives (versus liberals) generally tend to be more oriented towards protecting and benefitting their social “ingroups” (i.e., social groups to which they themselves belong), and exhibiting greater discrimination and aggression towards social “outgroups. ” However, empirical support for this theoretical perspective has been mixed. We argue that the empirical stalemate that characterizes this area of research stems from inherent limitations of the research paradigm used by both sides of the debate: examining attitudes towards real-world social groups. Drawing on research and theory from the social identity literature, we propose a novel approach—using “minimal groups” (i.e., experimentally constructed groups)—to answer whether, when, and why ideological differences in intergroup bias may exist. In this Registered Report proposal, we describe pilot data that we have collected that provide new insights into this longstanding debate, documenting both ideological symmetries and asymmetries in intergroup cognition, and suggesting that ideological extremity may also independently play a role in driving intergroup bias. We then propose additional research to more decisively answer these questions. We believe that this research will help reconcile this longstanding debate and provide a deeper understanding of the psychological underpinnings of political ideology. Introduction Tensions between the political right and left have grown in recent years, with greater polarization, increased animosity, and less willingness to engage with those of the opposing ideology (McCoy, Rahman, & Somer, 2018; Pew Research Center, 2014, 2016, 2017a; Reiljan, 2019). Indeed, the political divide is now one of the most contentious divisions in modern society (Iyengar & Westwood, 2015; Pew Research Center, 2016, 2017a, b). But what underlies these conflicting worldviews, and what factors influence whether a person adopts a more liberal versus conservative ideology? Several leading theories suggest that the left-right divide hinges on orientations towards social groups (e.g., Graham, Haidt, & Nosek, 2009; Terrizzi, Shook, & McDaniel, 2013; Thornhill & Fincher, 2007). More politically conservative people are argued to possess a suite of basic psychological traits and motivations that lead them to exhibit a relatively stronger preference for their social “ingroups” (i.e., the groups to which they belong) and relatively stronger prejudice/animosity towards social “outgroups” (i.e., groups to which they do not belong). However, the empirical evidence for this highly influential theoretical perspective has been mixed. While some research has found that conservatives generally exhibit greater intergroup bias (e.g., Altemeyer, 1981, 1988; Duckitt, 2001; Hodson & Busseri, 2012), other research has suggested there are no ideological differences in bias (e.g., Brandt, Reyna, Chambers, Crawford, & Wetherell, 2014; Chambers, Schlenker, & Collisson, 2013; Crawford, Brandt, Inbar, Chambers, & Motyl, 2017). Despite decades of research, this debate appears little closer to being resolved. We argue that the conflicting findings of past research are due to methodological limitations, and therefore a new methodological approach is needed to resolve this debate. Specifically, past research on both sides of the debate has focused almost exclusively on attitudes towards real-world social groups. Critically, such groups are confounded with complex histories and social information that makes it difficult—if not impossible—to measure a person’s “general” degree of intergroup bias. Further, both sides of this debate examine attitudes toward only a small subset of existing social groups—an approach especially vulnerable to biased stimuli selection, and one which captures only a fraction of the intergroup domain. In the present work, we draw on theory and methodology from social cognition to propose a novel test of whether conservatives are more predisposed than liberals to favor their own social groups over others. This approach is centered on the “minimal groups” paradigm (Brewer, 1979; Tajfel, 1970), which was designed to strip away the complex social information associated with real-world social groups in order to examine the most basic forms of intergroup bias (Spears & Otten, 2012; Tajfel, Billig, Bundy, & Flament, 1971). We present preliminary pilot data illustrating the insights this approach has yielded, then propose a programmatic series of studies that will provide a more decisive test of ideological differences in intergroup bias. In this work, we utilize several distinct indices of intergroup favoritism and a range of participant samples, and we systematically manipulate features of the intergroup context in order to understand the conditions under which ideological differences in intergroup bias are most likely to emerge. We believe that this research will help to adjudicate conflicting theoretical perspectives on the nature of the left-right political divide and, in doing so, may help us better understand how to resolve some of the real-world animosity between those of opposing ideologies. Conflicting Perspectives on Ideological Differences in Ingroup Favoritism Support for the ideological asymmetry hypothesis: The “ideological asymmetry hypothesis”—that more conservative belief systems are associated with greater intergroup bias— was first proposed in the early 1950s (Adorno, Frenkel-Brunswik, Levinson, & Sanford, 1950). Adorno and colleagues argued that individuals with a more “authoritarian” (i.e., conservative; Altemeyer, 1981) worldview were predisposed to hold greater prejudice against all types of social outgroups. Support for this argument rested on two central observations: 1) prejudices are positively correlated, such that individuals who are more prejudiced against one minority group tend to be more prejudiced against other minority groups, and 2) an authoritarian belief system strongly predicts this form of “generalized intergroup bias. ” This perspective has proven remarkably influential in political psychology in the intervening decades, and the idea that conservatives are fundamentally more prejudiced against social outgroups is central to many theories of political ideology and related belief systems (e.g., Altemeyer, 1981, 1988; Pratto, Sidanius, Stallworth, & Malle, 1994; Sidanius & Pratto, 1993; Wilson, 1973). Additional empirical support for this perspective comes from decades of research documenting that conservative belief systems tend to correlate with prejudice towards a wide range of minority groups (for a review, see Duckitt, 2001)—in line with Adorno and colleagues’ original findings. Other independent programs of research have converged on the conclusion that intergroup attitudes are central to the liberal-conservative ideological divide. For example, research from the moral foundations literature provides evidence of ideological differences in the relative weight assigned to ingroup-protective moral values (Graham, Haidt, & Nosek, 2009), reliably showing that political conservatives more strongly endorse moral values theorized to maintain ingroup cohesion and cooperation (e.g., ingroup loyalty and respect for authority; Haidt, 2007, 2012). In contrast, liberals tend to hold a more individualistic view of morality that does not privilege ingroups over outgroups (ibid.). Other recent theoretical perspectives have gone beyond positing a simple association between conservatism and ingroup favoritism in order to explicitly reconceptualize conservatism itself as a set of ideological beliefs or psychological motivations that are oriented towards protecting the ingroup—often at the expense of outgroups. From this perspective, conservative beliefs (particularly socially conservative beliefs) are defined as “ideological systems that promote ingroup homogeneity and outgroup avoidance” (Terrizi et al., 2013, p. 99). Similarly, evolutionary psychologists have argued that conservatism is a constellation of evolved psychological mechanisms designed to facilitate coalition building, to maintain ingroup cohesion, and ward off threats posed by outgroups. According to these accounts, conservatives are “in-group specialists” (Thornhill & Fincher, 2007, p. 215) who have a set of psychological traits that predispose them to form tighter-knit social groups, to exhibit greater favoritism toward their own social ingroups, and to be more likely to derogate and aggress against outgroups (e.g., Brown, Fincher, & Walasek, 2016; Haidt, 2012; Kessler & Cohrs, 2008; Sinn & Hayes, 2017; Tuschman, 2013). Conversely, liberals are argued to be “outgroup specialists” (Thornhill & Fincher, 2007, p. 215) who tend to make less of a psychological distinction between “us” and “them” and display relatively less favoritism towards their own groups. Together, these theoretical perspectives and lines of research appear to provide strong support for the hypothesis that political conservatives may tend to express greater intergroup bias than liberals. Although empirical support for the ideological asymmetry hypothesis has come exclusively from studies examining attitudes towards real-world social groups (particularly racial/ethnic, religious, and cultural groups), these theoretical perspectives further predict that conservatives’ greater ingroup favoritism should extend beyond particular social groups. That is, they contend that conservatives have particular psychological traits and motivations that lead them to exhibit greater intergroup bias in general, showing a greater preference for their own (vs. other) social groups – regardless of the origin or nature of that group. Support for the ideological symmetry hypothesis: In recent years, a rapi