News Release

Expertise improves shoot/no-shoot decisions in police officers and lessens potential for racial bias

Police outperformed students and community members in tests of speed and decision-making in shoot/no-shoot simulations

Peer-Reviewed Publication

American Psychological Association

WASHINGTON — From three experiments of video simulations of shoot-no shoot decision scenarios with police officers, community members and college students, researchers from the University of Chicago, the University of Colorado at Boulder and the University of Denver determined that training and experience is effective in minimizing decisions based on stereotyped views.

This finding is reported on in the June issue of the Journal of Personality and Social Psychology, published by the American Psychological Association (APA).

The research, which was funded by the Russell Sage Foundation, shows that police officers' decisions about whether to shoot or not to shoot a suspect are less susceptible to racial bias than decisions of community members. The authors say that an officers' training/expertise yields faster responses, greater sensitivity to the presence of a weapon and reduced tendencies to shoot a suspect because of his or her race. At the same time, suspect race did affect the speed with which both police officers and community members could formulate their decisions.

Using a video simulation of a shoot/don't shoot task, the first experiment compared the speed and accuracy of 113 officers from around the United States, 124 Denver police officers and 135 community members from Denver. The simulation involved armed and unarmed White and Black men appearing in a variety of background images. Participants were instructed to respond to armed targets with a shoot response and to unarmed targets with a don't shoot response as quickly as possible.

The officers outperformed the community members on several measures. They were faster in making correct responses and better at detecting the presence of a weapon. Furthermore, whereas community members were more likely to shoot an unarmed target if he was Black rather than White, police showed no such tendency. At the same time, both officers and community members responded more slowly to unarmed Black targets, suggesting that all participants (regardless of training) had difficulty formulating the correct response. Police officers, however, seemed to overcome this difficulty, ultimately making less biased decisions.

In the second experiment, 33 officers were compared with 52 community members in the shoot/don't shoot task but with a more restrictive time frame. Again, compared to the community members, the police officers were better able to discriminate armed from unarmed targets and were less likely to shoot an unarmed target or be influenced by the target's race.

The last experiment involved 58 college students participating in the video simulation shoot/don't shoot task using the first experiment's time frame. This experiment took place over two days and involved repeated play to allow the participants to improve their performance from one day to the next. Practice with the task increased the participants' sensitivity to the presence or absence of a weapon and significantly reduced bias in participants' errors.

The fact that the police officers in both experiments 1 and 2 showed no racial bias in their errors during the video game task may be a testament to their training and expertise, say the authors. But the fact that race affected reaction times suggests that stereotypes still play some role in shoot/no-shoot decisions.

Furthermore, functional magnetic resonance imaging (fMRI) results from other experiments that tested peripheral distractions and accuracy showed how training works in the brain. "Extended practice on difficult tasks may lead to increased activation of brain regions associated with conflict resolution and top-down, rule-based processing. Police training along with on-the-job experience in complex encounters may similarly allow officers to exert control in the shoot/don't shoot simulation, overriding response tendencies that stem from racial stereotypes," said lead author Joshua Correll, PhD.

The research suggests how important training and expertise are in overriding a person's automatic response to perceived dangerous situations/stimuli. "Most of our research suggests that knowledge of cultural stereotypes (which we are aware of, even if we don't believe them) is sufficient to engender bias in this task. Training may be especially important for law enforcement personnel since their jobs require them to make quick decisions in ambiguous situations with potentially life-or-death consequences," said Correll.


A press conference on the study will be held at 11:00 AM (MDT) on FRIDAY, JUNE 1, 2007 at:

Police Headquarters
1331 Cherokee St.
Denver, CO 80204

Contact: Denver Police Media Office
(720) 913-6028

Article: "Across the Thin Blue Line: Police Officers and Racial Bias in the Decision to Shoot," Joshua Correll and Bernd Wittenbrink, PhD, University of Chicago; Bernadette Park, PhD, Charles M. Judd, PhD, and Melody S. Sadler, University of Colorado at Boulder; Tracie Keesee, University of Denver; Journal of Personality and Social Psychology, Vol. 92, No. 6.

Full text of the article is available from the APA Public Affairs Office or at

Joshua Correll, PhD, can be reached by phone at 773-834-3704, cell 720-938-4448; 312-259-7885 or by email:

The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world's largest association of psychologists. APA's membership includes more than 148,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting health, education and human welfare.

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