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.

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.

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractBaron and Jost (this issue) present three critiques of our meta-analysis demonstrating similar levels of partisan bias in liberals and conservatives: 1) that the studies we examined were biased toward finding symmetrical bias among liberals and conservatives, 2) that the studies we examined do not measure partisan bias but rather rational Bayesian updating, and 3) that social psychology is not biased in favor of liberals but biased instead toward creating false equivalencies. We respond in turn that: 1) 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 opportunity to demonstrate bias, 2) we carefully selected studies that were least vulnerable to Bayesian counterexplanation and most scientists and laypeople consider these studies demonstrations of bias, and 3) there is reason to be vigilant about liberal bias in social psychology, but this does not preclude concern 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.

People believe that effort is valuable, but what kind of value does it confer? We find that displays of effort signal moral character. Eight studies (N = 5,502) demonstrate the nature of these effects in the domains of paid employment, personal fitness, and charitable fundraising. The exertion of effort is deemed morally admirable (Studies 1-6) and is monetarily rewarded (Studies 2-6), even in situations where effort does not directly generate additional product, quality, or economic value. Convergent patterns of results emerged in South Korean and French cross-cultural replications (Studies 2b and 2c). We contend that the seeming irrationality of valuing effort for its own sake, such as in situations where one's efforts do not directly increase economic output (Studies 3-6), reveals a "deeply rational" social heuristic for evaluating potential cooperation partners. Specifically, effort cues engender broad moral trait ascriptions, and this moralization of effort influences donation behaviors (Study 5) and cooperative partner choice decision-making (Studies 4 and 6). In situating our account of effort moralization into past research and theorizing, we also consider the implications of these effects for social welfare policy and the future of work.

Deep partisan conflict in the mass public threatens the stability of American democracy. We conducted a megastudy (n=32,059) testing 25 interventions designed by academics and practitioners to reduce Americans’ partisan animosity and anti-democratic attitudes. We find nearly every intervention reduced partisan animosity, most strongly by highlighting sympathetic and relatable individuals with different political beliefs. We also identify several interventions that reduced support for undemocratic practices and partisan violence, most strongly by correcting misperceptions of outpartisans’ views – showing that anti-democratic attitudes, although difficult to move, are not intractable. Furthermore, both factor analysis and patterns of intervention effect sizes provide convergent evidence for limited overlap between these sets of outcomes, suggesting that, contrary to popular belief, different strategies are most effective for reducing partisan animosity versus anti-democratic attitudes. Taken together, our findings provide a toolkit of promising strategies for practitioners and shed new theoretical light on challenges facing American democracy.