Realism of confidence in sensory discrimination

Is there a common and general basis for confidence in human judgment? Recently, we found that the properties of confidence judgments in the sensory domain mirror those previously established in the cognitive domain; notably, we found underconfidence on easy sensory judgments and overconfidence on hard sensory judgments. In contrast, data from the Uppsala laboratory in Sweden suggest that sensory judgments are unique; they found a pervasive underconfidence bias, with overconfidence being evident only on very hard sensory judgments. Olsson and Winman (1996) attempted to resolve the debate on the basis of methodological issues related to features of the stimulus display in a visual discrimination task. A reanalysis of the data reported in Baranski and Petrusic (1994), together with the findings of a new experiment that controlled stimulus display characteristics, supports the position that the difference between the Canadian and the Swedish data is real and, thus, may reflect cross-national differences in confidence in sensory discrimination.