NUMERICAL DISTANCE AND ANCHORING EFFECTS IN JUDGING CONFIDENCE

On half of the trials in a sensory detection task, participants were required to decide whether they were more or less confident of the correctness of their decision than the confidence denoted by a number N ranging from 55 to 95. Subsequently, participants expressed confidence on a scale ranging from 50 to 100. On the other half of the trials, participants simply rendered confidence. Times to compare the internal confidence estimate to the numerical value N revealed numerical distance effects; as the distance between N and their subsequently rendered levels of confidence increased, response times decreased. Analyses of mean confidence ratings revealed anchoring effects, with mean absolute confidence ratings assimilating toward the value of N. Research over the past decade has demonstrated how confidence processing in human judgement originates during the primary decision-making process and continues post