tunnel vision

Tunnel vision metaphorically denotes a collection of common heuristics and logical fallacies that lead individuals to focus on cues that are consistent with their opinion and filter out cues that are inconsistent with their viewpoint. It is a phenomenon mostly widely observed and researched in the field of criminology due to its prevalence and dangerous potential to create incorrect convictions. Tunnel vision is also related to confirmation bias. Confirmation bias is over-reliance on external sources that may be inaccurate yet supports an individual’s opinion, whereas tunnel vision is over-reliance on internal information whilst ignoring correct external information. The common way to solve this problem is a second opinion, that is, getting somebody unrelated to the original investigation to look at it from the beginning, without the same biases and preconceptions. This is generally due to bias from preceding incidents. Tunnel vision within the criminal justice system Within the criminal justice system tunnel vision refers to the tendency of investigators and prosecutors to use heuristics to filter evidence in order to build a case for a suspect’s conviction in a discriminatory manner. Importance is given to information that supports their original conclusion and inconsistent information is overlooked. This has been associated with the tendency of police investigators to presume guilt which has been shown to increase with experience and training. Elaad conducted a study in order to examine the effects of tunnel vision on Israeli police investigators and laypeople in hypothetical criminal investigation situations. Two scenarios of criminal incidents were combined with intelligence information that was either incriminating (supporting the suspect’s guilt) or exonerating (supporting the suspect’s innocence). Participants were asked to indicate their confidence in the suspect’s innocence or guilt on an 11-point scale. Results showed that police investigators assigned higher confidence scores in the suspect’s guiltiness than laypeople when both incriminating and exonerating evidence was presented. Investigators were more strongly influenced by tunnel vision than laypersons.