Peer influence on conformity and confidence in a perceptual judgment task

Undergraduate college students were presented with two arrays of dots varying in numerosity on a computer screen and asked to indicate if the arrays differed in number. They also rated their level of confidence in their responses. Trials varied in difficulty based on the size of the arrays. On half of the trials, participants were shown the ostensible responses of confederates to test the effect of peer influence on numerosity judgments and participant confidence. On the other half of the trials, participants received no information about the responses of the confederates to provide a measure of baseline performance. Higher levels of conformity were observed for the difficult trials, on which participants were both less accurate and less confident. However, confidence ratings were influenced by peer judgments for easy trials but not for difficult trials. These data suggest that task difficulty influences conformity when making perceptual judgments.