Wednesday, July 9, 2008, 8:18pm
In 2003, a team led by J. Correll flashed random photos of white and black faces, some superimposed with guns, others with harmless items such as cell phones and wallets. They asked college students to press one key indicating "shoot" the suspect, and another indicating "don't shoot." The students were more likely to mistakenly fire at black faces that were unarmed compared to unarmed white faces.
But what about police officers? With their special training and rules about when to fire, perhaps they will do better. A study by E. Ashby Plant and B. Michelle Peruche tested police officers on a similar task.
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48 mostly white police officers who volunteered to participate in the project were told only that the study was about "decisions to shoot." They had 630 milliseconds after each face was displayed to press the "shoot" or "don't shoot" button on the computer running the test. As the test began, results were the same as with college students: Police officers were more likely to mistakenly shoot black suspects holding harmless items than white suspects holding the same items. They made an average of 3.63 errors over 20 trials when the suspect was black, but only 2.65 errors when the suspect was white.
But an interesting result occurred as the test continued. After another 80 trials, about 40 of which included the key situation of a person holding a harmless object, the disparity between reactions to white and black suspects disappeared. During the second half of the experiment, the average number of errors for black suspects diminished to 2.60, statistically indistinguishable from the rate for white suspects.