Cognitive Daily

ResearchBlogging.orgIn 2005, E. Ashby Plant and B. Michelle Peruche tested 48 Florida police officers and found that they were initially more likely to shoot unarmed Black “suspects” in a crime-fighting simulation than White people holding similar objects. Interestingly, however, as the test went on, the officers improved, and by the end of the session, any bias had been removed.

But in the real world, officers don’t get a second chance, and accidental shootings do occur. In many communities, racial tensions are already running high, and an interracial shooting by a police officer can bring those tensions to the boiling point — causing even more damage than the shooting itself. It’s critical to understand why these accidents happen and what can be done to prevent them, not only to protect innocent suspects, but also to build community trust in police officers and increase the effectiveness of law enforcement.

Joshua Correll and five other researchers devised a test to assess racial bias shooting that was similar to Plant and Peruche’s, but also more realistic. Twenty-five Black actors and twenty-five White actors were photographed holding either a gun or a benign object like a wallet or can of cola in several different poses. In the new test, random backgrounds (urban scenes, country roads, etc.) were flashed on a computer screen. At random intervals, one of the actors was inserted into the screen. Then the police officer had to decide whether to shoot or not shoot as quickly as possible, and press a button registering his or her response.

This test was given to three groups of people: 124 Denver police officers, 113 police officers from across the U.S., and 135 Denver civilians. Was there any bias in the decision to shoot? This graph shows the results of a statistical measure, c, designed to measure propensity to shoot an unarmed person:


The police from the national sample were no more likely to shoot unarmed Black suspects than unarmed White suspects (I’ve used the inverse of the actual c values to make this graph easier to read). While the Denver police showed a small propensity to shoot unarmed Black suspects, this didn’t rise to the level of significance. Only the civilians were more likely to shoot unarmed Black suspects at a statistically significant level.

However, further analysis of the data revealed something more interesting. Among the national officers, there was a significant correlation (r=.31) between racial bias and the size of the urban area where the officers worked, as well as a correlation (r=22) between the proportion of ethnic minorities in their community and racial bias. So officers who worked in larger cities were more likely to show bias against unarmed black suspects, as were officers in areas with larger minority populations.

So while overall there doesn’t appear to be much bias toward shooting unarmed Black suspects among police, where the bias does occur seems to be the areas where it’s most likely to occur: places where more minorities are living.

The researchers also attempted to measure racist attitudes among the police officers, and they didn’t find any correlation between racist beliefs and racial bias in shooting. But many of the officers either refused to answer this part of the survey or told the researchers (off the record) that they hadn’t answered those questions honestly — the officers knew what was being tested, and knew how to give the “right” answers, even when that wasn’t what they actually believed.

Perhaps most interesting of all is the case of police who’d had a particular type of training involving live actors, some unarmed, and some “armed” with paintball guns or other non-lethal weapons. This training correlated with significantly better ability to detect whether a suspect was armed or unarmed, regardless of race. Police engage in a variety of training, ranging from video simulations to target practice, but only this particular type of training revealed itself to be particularly effective in preventing accidental shootings — at least in the simulated task that was used in this study.

So while some racial bias was found in this study, Correll’s team was able to identify both where it was most likely to occur, and some potential ways to reduce racial bias even further. Let’s hope that police departments begin to put this information to good use.

Joshua Correll, Bernadette Park, Charles M. Judd, Bernd Wittenbrink, Melody S. Sadler, Tracie Keesee (2007). Across the thin blue line: Police officers and racial bias in the decision to shoot. Journal of Personality and Social Psychology, 92 (6), 1006-1023 DOI: 10.1037/0022-3514.92.6.1006


  1. #1 Amir massoud
    July 9, 2008

    And it would be interesting if one can observe the effect of the race of the officers to this racial bias. Is it the case that black officers tend to shoot white suspects more often than shooting black suspects?

  2. #2 Nancy Shanteau
    July 9, 2008

    I definitely think police training around shooting unarmed suspects is an important item and finding – and it’s helpful to know which training is most useful.

    Still, I would hope that an additional result would be the galvanization of readers to address their own internalized racial bias; to put away the notion that we are anything but a racist country, and to begin to address the issue personally and collectively.

    If readers are already doing their own work to reduce their racial bias, bravo.

    Do the authors have any suggestions for civilians as we work through our own bias?

  3. #3 LS
    July 10, 2008

    My follow up to the question posed by Amir is, do we have any knowledge of the ethnic breakdown of the police officers? I think the supposition is that the officers and civilians were white. My theory is that there would be no difference in the responses between black and white officers because of the police culture that supports their stereotypes. Similarly, the general public is bombarded by media that may skew their thinking as well. What this does show conclusively to me is the need for extensive training to overcome the bias of the officer.

  4. #4 Nigel
    July 10, 2008

    Hmm, so police are only inclined to shoot unarmed black people if they work in areas where there are plenty of unarmed black people around to be shot. That’s alright then.

  5. #5 caynazzo
    July 11, 2008

    In one sense the interpretation of the data–familiarity increases bias–is surprising. In this case, an area with a larger concentration of minorities increases the chances that they’ll be racially profiled. One would assume the opposite to be the case.

  6. #6 Eleanor
    July 11, 2008

    Re headline –

    I am sure this is a great comfort to those unusual suspects toward whom the police cannot curb their racial bias.

  7. #7 Katya
    July 12, 2008

    Re comment #5 – the familiarity in this case is likely to contribute to a negative image of minority suspects, because an area with a higher concentration of people (minority, in this case) will have a higher crime rate, so the link between race and crime is more readily established.

  8. #8 S. Wednesday
    July 14, 2008

    In response to Amir and LS – with respect to racial bias of the officers and civilians there appears to have been no difference between whites and non-whites in their “propensity to shoot”. Because the majority of participants were white, all other participant scores were collapsed into a single non-white group to allow for meaningful analyses.

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