When confidence in a choice is independent of which choice is made

For forced-choice two-alternative general-information questions, confidence in the correctness of the answer differed reliably for different questions, regardless of which answer was chosen. Results suggested that this choice-independent confidence is mediated by the domain familiarity of the question and by its tendency to bring to mind either few or many thoughts and considerations. Ratings of the questions on familiarity and accessibility yielded strong correlations with participants’ confidence in whichever of two answers they had chosen, and with estimates of the percentage of participants who were likely to have chosen either of the answers in a previous experiment. The results were interpreted in terms of confirmation bias: Because items differ in the extent to which they bring to mind few or many pertinent thoughts, selective focusing on supportive evidence should yield a positive correlation between mean confidence in one answer and mean confidence in the alternative answer, as if there is no competition between them.