Interpreting politically-charged numerical information: The influence of numeracy and problem difficulty on response accuracy

People who possess greater mathematical skills (i.e., numeracy) are generally more accurate in interpreting numerical data than less numerate people. However, recent evidence has suggested that more numerate people may use their numerical skills to interpret data only if their initial interpretation conflicts with their worldview. That is, if an initial, intuitive (but incorrect) interpretation of data appears to disconfirm one’s beliefs, then numerical skills are used to further process the data and reach the correct interpretation, whereas numerical skills are not used in situations where an initial incorrect interpretation of the data appears to confirm one’s beliefs (i.e., motivated numeracy). In the present study, participants were presented with several data problems, some with correct answers confirming their political views and other disconfirming their views. The difficulty of these problems was manipulated to examine how numeracy would influence the rate of correct responses on easier vs. more difficult problems. Results indicated that participants were more likely to answer problems correctly if the correct answer confirmed rather than disconfirmed their political views, and this response pattern did not depend on problem difficulty or numerical skill. Although more numerate participants were more accurate overall, this was true both for problems in which the correct answer confirmed and disconfirmed participants’ political views.