Deliberation enhances the confirmation bias. An examination of politics and religion

This paper present new evidence on the confirmation bias in two polarizing topic areas: politics and religion. While a reasonable amount of evidence has documented this bias in the domain of politics, relatively little existing research has examined the confirmation bias in religion. I developed a novel task in the religious domain to examine the presence of the confirmation bias and its comparative strength compared to that observed in the political domain. Using a preregistered data collection and analysis plan, I examine data from n=402 participants who were prescreened to be distinct in terms of political and religious beliefs. Each was administered a two-pronged confirmation bias online that examined selective information exposure and perceived strength of arguments incongruent to one’s own beliefs regarding “gun control” and the “existence of God”. Results showed strong support for the existence of a confirmation bias along both dimensions and in terms of both information exposure and perceived argument strength. I also examined the hypothesis that the confirmation bias is actually stronger in situations where more thought or deliberation is brought to bear on the task. The evidence here depends on the measure of deliberation used, but generally is in the direction hypothesized. More strongly, we find that individuals who have thought a lot about the topic at hand (gun control and the existence of God displayed more of a confirmation bias in perceived argument strength than those having thought less about the issue. A main contribution of this paper is to offer new evidence documenting the confirmation bias in a more direct task comparison across domains. And, the findings regarding how deliberation may worsen the bias are in line with previous research suggesting the confirmation bias may be unlike other decision biases—this bias may thrive when the decision maker is more is more deliberative or thoughtful. Key Words: Confirmation bias, decision bias, politics, religion, behavioral economics