The SPOT effect: People spontaneously prefer their own theories.

People often exhibit confirmation bias: They process information bearing on the truth of their theories in a way that facilitates their continuing to regard those theories as true. Here, we tested whether confirmation bias would emerge even under the most minimal of conditions. Specifically, we tested whether drawing a nominal link between the self and a theory would suffice to bias people towards regarding that theory as true. If, all else equal, people regard the self as good (i.e., engage in self-enhancement), and good theories are true (in accord with their intended function), then people should regard their own theories as true; otherwise put, they should manifest a spontaneous preference for their own theories (i.e., a SPOT effect). In three experiments, participants were introduced to a theory about which of two imaginary alien species preyed upon the other. Participants then considered in turn several items of evidence bearing on the theory and each time evaluated the likelihood that the theory was true versus false. As hypothesized, participants regarded the theory as more likely to be true when it was arbitrarily ascribed to them as opposed to an "Alex" (Experiment 1) or to no one (Experiment 2). We also found that the SPOT effect failed to converge with four different indices of self-enhancement (Experiment 3), suggesting that it may be distinctive in character.