Dopaminergic Genes Predictive of Unmotivated Confirmation Bias are not Predictive of Motivated Confirmation Bias

Abstract

Confirmation bias is persistently devastating to rational judgment and decision-making. Previous research supports cognitive and behavioral distinctions between two types of confirmation bias: motivated confirmation bias and unmotivated confirmation bias. Motivated confirmation bias is a member of the larger class of motivated reasoning biases. These often occur when one’s individual or group identity is tied up in certain beliefs or propositions that command one’s assent. Prior research has shown that even when individuals possess cognitive problem-solving skills such as high numeracy, these skills offer no benefit to rational thinking or judgment in the face of motivated reasoning problem sets. Prior research has also shown that dopaminergic genes DRD2, DARPP-32, and COMT are predictive of susceptibility to unmotivated confirmation bias; however, the role of these genes in motivated confirmation bias had yet to be tested. The present investigation examined the possible connection. Participants were 200 university students who completed questionnaires and tasks assessing motivated confirmation bias, numeracy, political philosophy and party identification. Logistic regression modeled the association of these measures with accuracy on a bias detection task. Numeracy predicted accuracy; however, genotypes and political measures did not. These results suggest that distinct genetic determinants are responsible for motivated and unmotivated confirmation bias. Further, the findings replicated previous research demonstrating that accuracy is much diminished in the motivated scenario compared to an unmotivated control. However, contrary to this earlier work, the current findings suggest that numeracy confers a benefit in both motivated and unmotivated conditions, rather than just in motivated situations. Overall, these findings suggest continued research is needed to uncover the neurobiological determinants of motivated confirmation bias.