More evidence isn't better evidence

Psychologists Matthew Fisher and Frank Keil similarly uncovered black-and-white thinking in the way we interpret marbled information. 14 They gave a group of 150 students several pieces of eyewitness testimony. Some were unambiguous, such as ‘One witness is 100% confident that the defendant did not commit crime X,’ but others were mixed, such as ‘One witness is 50% confident that the defendant did not commit crime X.’ After seeing all the evidence, each subject was asked how likely it was that the defendant was guilty. Matthew and Frank found that this assessment was driven by the number of proversus anti-statements, not their strength.