In the psychological study of belief updating, the theory of “confirmation bias” has been supreme. The idea that we find evidence to support our pre-existing beliefs while ignoring that which refutes them is well supported by many studies and research. However, it may not even be the predominant factor in whether we update our beliefs.

In a study by Leslie van de Leer et al., participants indicated who they desired and who they believed would win in the 2016 election. Following a confrontation with evidence that was either consistent or inconsistent with their desires or beliefs, they again indicated who they believed would win. The researchers observed a robust desirability bias—individuals updated their beliefs more if the evidence was consistent (versus inconsistent) with their desired outcome. This bias was independent of whether the evidence was consistent or inconsistent with their prior beliefs. In contrast, they found limited evidence that confirmation bias was working independently at all in belief updating.