Skilled Observation and Change Blindness: A Comparison of Law Enforcement and Student Samples

Abstract

Some evidence suggests that expertise and observational skills training can reduce attentional errors, such as change blindness. Laypeople typically assume that law enforcement officers possess acute observational skills, but no research to date has compared law enforcement and lay samples on their susceptibility to change blindness. In the present study, student and law enforcement samples completed a change blindness task and attempted to identify the target(s) from four line-ups. Law enforcement officers and students were equally susceptible to change blindness regarding the switch in the target's identity, but students were more likely than officers to detect changes in the target's clothing. Students also performed better on the line-up task, overall, than officers. Additionally, whereas students' confidence was positively correlated with identification accuracy under some circumstances, officers' confidence was either uncorrelated or negatively correlated with accuracy. We discuss the implications of these findings and suggest some factors accounting for law enforcement officers' relatively poor performance on these tasks.

Observing offenders: Incident reports by surveillance detectives, uniformed police, and civilians

“…In the present study, we eliminated the confounding effect of information by providing all participants with instructions regarding what aspects of the incident to focus on (i.e., a priority list of crime‐relevant aspects). Nevertheless, we found that detectives and uniformed police officers reported significantly more information than civilians, particularly about the top priorities from an investigative perspective: Vehicles, times, and phones (see Kalteis, ; Lindholm et al ., ; Smart et al ., ; for similar findings). This suggests that ‘experienced police officers, because of their professional knowledge and experience of violent crime situations, are more able to isolate and analyse information from crime‐relevant incidences than the general public’ (Yarmey, , p. 239).…”

“…Studies of police officers’ and civilians’ memory for observed incidents have yielded somewhat mixed findings. Some researchers found no overall difference between police and civilians in memory reporting about witnessed incidents (Smart et al ., ; Stanny & Johnson, ; Verinis & Walker, ), whereas other researchers found that police officers remembered significantly more correct information than civilians (Christianson et al ., ; Clifford & Richards, ; Thomassin & Alain, ; Yuille, ). An explanation for these mixed findings may be that police officers remember some types of details better than civilians, but not other types of details.…”

“…To date, this belief is not supported by the empirical evidence. Most studies reveal no differences between police officers and civilians in overall identification accuracy (Christianson et al ., ; Lindholm et al ., ; Smart et al ., ). The only difference between groups is that police officers are more likely than civilians to incorrectly identify someone from a lineup in which the target is absent (i.e., a false alarm; Kalteis, ; Smart et al ., ; Thomassin & Alain, ; see also Yuille, ).…”

“…Finally, Smart et al . () showed participants a video of a traffic stop in which the driver walks out of the frame and is replaced by a different person wearing a different shirt (i.e., a change‐blindness experiment; cf. Rensink, O'Regan, & Clark, ; Simons & Levin, ).…”

“…An explanation for these mixed findings may be that police officers remember some types of details better than civilians, but not other types of details. Specifically, police officers have been found to report more crime‐relevant information, such as descriptions of perpetrators, weapons, or vehicles, but not more peripheral information, such as descriptions of non‐perpetrators and contextual information (Kalteis, ; Lindholm et al ., ; Smart et al ., ). In sum, police officers outperform civilians in reporting crime‐relevant information, but not in reporting other types of information.…”