Brendan Nyhan, Jason Reifler, and a group of undergraduates have released the findings of an experimental study that compares different strategies to correct the popular misconception that Obama is a Muslim:
In this paper, we address the question of how to counter political misperceptions, which are often difficult or impossible to eradicate. One explanation for this difficulty is that corrections frequently take the form of a negation (i.e. “Tom is not sick”), a construction that may fail to reduce the association between the subject and the concept being negated (Mayo et al. 2004). We apply this approach to the persistent rumor from the 2008 presidential campaign that Barack Obama is a Muslim, comparing the effectiveness of what we call a misperception negation (“I am not and never have been of the Muslim faith”) with what we call a corrective affirmation (“I am a Christian”), which should be more effective. As expected, we find that the misperception negation was ineffective. However, our hypothesis that the corrective affirmation would successfully reduce misperceptions was only supported when a non-white experimental administrator was present, suggesting a strong social desirability effect on the acceptance of corrective information. In addition, three-way interactions between the corrective affirmation, race of administrator, and party identification suggest that social desirability effects were more prevalent among Republicans. When nonwhite administrators were absent, the corrective affirmation not only failed to reduce Republican misperceptions but caused a backfire effect in which GOP identifiers became more likely to believe Obama is Muslim and less likely to believe he was being honest about his religion. We interpret this reaction as being driven by Obama’s embrace of Christianity, which may provoke cognitive dissonance among Republicans.
Read Nyhan’s blog post about the paper, access the full paper and read responses from Think Progress’s Matthew Yglesias and Politico’s Ben Smith.