The Impact of Outcome Knowledge, Role, and Quality of Information on the Perceived Legitimacy of Lethal Force Decisions in Counter-Terrorism Operations

According to the phenomenon of hindsight bias, once people know the outcome of an event, they tend to have biased estimates of the probability that the event would have occurred. In this study, we investigated whether hindsight bias affected judgements about the legitimacy of lethal force decisions in police shooting incidents for counter-terrorism operations. We also assessed to what extent this hindsight bias was mediated by factors such as role and information quality. Four hundred and eighty participants completed a short questionnaire that manipulated role (as senior police officer, Independent Police Complaints Commissioner, or family member, plus a "no role" control group), information quality (detailed/good or vague/ambiguous), and outcome knowledge (knowledge of outcome/hindsight versus no knowledge of outcome/foresight) in a 4 x 2 x 2 design. Results indicated that outcome knowledge affected the perception of threat and decision quality but not the blameworthiness of the senior police officer. Quality of information had a significant effect on all three dependent variables and role had a significant impact on judgements as to whether the decision to shoot was correct and also the perceived threat, though not on perceived blameworthiness. These findings indicate that people who have to judge the liability of lethal force decisions are not able to ignore outcome information, and are strongly influenced by the quality of information and by the role in which they are receiving the information. Copyright (C) 2009 John Wiley & Sons, Ltd.