Dual Decision Threshold Model. Classic, expected utility threshold probability as a function of benefit/harms ratio as derived by system II, EUT (expected utility threshold) (solid line). The treatment should be given if the probability of disease is above the threshold, otherwise should be withheld. Note that if system I perceives that harms are higher than system I benefits (BI < HI), the threshold probability is always higher than classic EUT (dotted line). However, if BI > HI, the threshold probability is always lower than the EUT threshold (dashed line) (see text for details).