Partisan Bias and Its Discontents.

Baron and Jost (this issue, p. 292) present three critiques of our meta-analysis demonstrating similar levels of partisan bias in liberals and conservatives: (a) that the studies we examined were biased toward finding symmetrical bias among liberals and conservatives, (b) that the studies we examined do not measure partisan bias but rather rational Bayesian updating, and (c) that social psychology is not biased in favor of liberals but rather toward creating false equivalencies. We respond in turn that (a) the included studies covered a wide variety of issues at the core of contemporary political conflict and fairly compared bias by establishing conditions under which both liberals and conservatives would have similar motivations and opportunities to demonstrate bias; (b) we carefully selected studies that were least vulnerable to Bayesian counterexplanation, and most scientists and laypeople consider these studies demonstrations of bias; and (c) there is reason to be vigilant about liberal bias in social psychology, but this does not preclude concerns about other possible biases, all of which threaten good science. We close with recommendations for future research and urge researchers to move beyond broad generalizations of political differences that are insensitive to time and context.

At Least Bias Is Bipartisan: A Meta-Analytic Comparison of Partisan Bias in Liberals and Conservatives.

Both liberals and conservatives accuse their political opponents of partisan bias, but is there empirical evidence that one side of the political aisle is indeed more biased than the other? To address this question, we meta-analyzed the results of 51 experimental studies, involving over 18,000 participants, that examined one form of partisan bias-the tendency to evaluate otherwise identical information more favorably when it supports one's political beliefs or allegiances than when it challenges those beliefs or allegiances. Two hypotheses based on previous literature were tested: an asymmetry hypothesis (predicting greater partisan bias in conservatives than in liberals) and a symmetry hypothesis (predicting equal levels of partisan bias in liberals and conservatives). Mean overall partisan bias was robust ( r = .245), and there was strong support for the symmetry hypothesis: Liberals ( r = .235) and conservatives ( r = .255) showed no difference in mean levels of bias across studies. Moderator analyses reveal this pattern to be consistent across a number of different methodological variations and political topics. Implications of the current findings for the ongoing ideological symmetry debate and the role of partisan bias in scientific discourse and political conflict are discussed.