Bill Clinton is reported to have complained that getting Democrats to agree on a course of action was like herding cats, while the Republicans didn’t seem to have this problem. Stern et al. do a fascinating nugget of work that shows that conservatives and moderates overestimate the degree to which others conservative and moderates are like them, while those on the left end of the spectrum assume they are more unique among party peers than they actually are. (Recall the inability of the Occupy Wall Street movement in 2011 to achieve consensus on vital issues.)
The authors used well-validated methodology for examining truly false consensus and truly false uniqueness effects by developing a procedure in which participants were asked to indicate their beliefs and their preferences for a series of items and then estimate the beliefs and preferences of political in-group members. To test for truly false uniqueness and truly false consensus effects, They compared the extent to which participants perceived that political in-group members shared their beliefs and preferences with the extent to which political in-group members actually shared participants’ beliefs and preferences. From their methods section:
We conducted two studies in which participants reported their beliefs and preferences and estimated the beliefs and preferences of political in-group members who were either fellow participants in the study (Study 1) or members of the general American population (Study 2). This procedure allowed us to examine whether similar patterns of effects would emerge even when participants thought about political in-group members in different contexts. In Study 2, we replicated and extended Study 1 by examining whether the desire to feel unique explains in part ideological differences in estimating similarity to political in-group members. Finally, previous research has shown that individuals perceive more similarity between their own beliefs and those of other individuals (i.e., perceive greater consensus) when the beliefs are socially desirable or personally important. To rule out the possibility that these factors explain ideological differences in perceiving similarity to political in-group members, we measured the perceived social desirability of the items to which participants responded in both studies. In addition, in Study 2, we measured the personal importance of the items to rule out the possibility that this factor would explain ideological differences in perceiving similarity.Here is their brief abstract.
In two studies, we demonstrated that liberals underestimate their similarity to other liberals (i.e., display truly false uniqueness), whereas moderates and conservatives overestimate their similarity to other moderates and conservatives (i.e., display truly false consensus; Studies 1 and 2). We further demonstrated that a fundamental difference between liberals and conservatives in the motivation to feel unique explains this ideological distinction in the accuracy of estimating similarity (Study 2). Implications of the accuracy of consensus estimates for mobilizing liberal and conservative political movements are discussed.