Confirmation Bias in Criminal Investigations

Abstract:     
Confirmation bias is the tendency to bolster a hypothesis by seeking consistent evidence while disregarding inconsistent evidence. In criminal investigations, preference for hypothesis-consistent information could contribute to false convictions by leading investigators to disregard evidence that challenges their theory of a case. Two studies examine factors that influence confirmation bias in criminal investigations. In study 1, participants (N = 108) who stated hypotheses early in their review of a mock police file showed bias in seeking and interpreting evidence. In study 2 (N = 109), asking participants to consider why a hypothesis might be wrong remedied bias, but asking them to generate additional hypotheses did not. Implications for improving accuracy of investigations and suggestions for future research are discussed.

Number of Pages in PDF File: 34

Keywords: confirmation bias, false convictions

working papers series