Cultural stereotypes can influence perceptions, judgments, and behavior, even if these stereotypes do not necessarily reflect personal beliefs.

In February 1999, Amadou Diallo, a 22-year-old West African immigrant, was shot in the doorway of his apartment building by four plain clothes police officers searching a Bronx, New York neighborhood for a rape suspect. When the officers ordered him not to move, Diallo reached into his pants pocket. Believing he was reaching for a gun, the officers fired a total of 41 shots, 19 of which hit and killed Diallo, who turned out to be unarmed. All four officers were later acquitted of wrongdoing in the case.

Would the police officers have responded differently if Diallo had been white? Perhaps the order to freeze would have been repeated. A slight delay in the decision to fire would have given the officers time to recognize that Diallo was not reaching for a gun.

The questions raised by the Diallo shooting were a catalyst for the study, "The Police Officer's Dilemma: Using Ethnicity to Disambiguate Potentially Threatening Individuals," by University of Chicago Professor Bernd Wittenbrink, and Joshua Correll, Bernadette Park, and Charles M. Judd of the University of Colorado at Boulder.

The authors analyzed the shoot/don't shoot decision facing police officers using a simplified videogame. The videogame roughly simulates the situation of a police officer who is confronted with an ambiguous, but potentially hostile, target.

In the videogame experiment, images of men who are armed with a gun or carrying an innocuous object (such as a cell phone), and who are either African-American or white, appear unexpectedly in a variety of contexts. Participants were told to "shoot" armed targets and to "not shoot" unarmed targets. The experiment recorded participants' responses and the speed with which they made their decisions.

The goal was to investigate the effect of a target's ethnicity on participants' decisions to shoot that target.

In the speed of the participants' responses and the errors they made, the authors find that the target's ethnicity does indeed affect the decision to shoot.

Participants more often incorrectly decided to shoot an unarmed target when he was African-American than when he was white. At the same time, they more often failed to respond with a "shoot" decision when the armed target was white than when he was African-American. Likewise, participants' response speed also showed the influence of ethnicity on the ease with which these decisions can be made. Participants made the correct decision to shoot an armed target faster if the target was African-American than if he was white, but decided not to shoot an unarmed target more quickly if he was white, than if he was African-American.

Although the differences due to the target's ethnicity are not large, they are stable, and the authors have found these results repeatedly across several experiments with participants from varying backgrounds. For example, the authors find the same pattern of results in experiments conducted with both African-American and white participants, as well as with a group of active-duty police officers who took part in one of the experiments.

In addition, the effects of target ethnicity occur even though participants in the experiments are motivated to make accurate decisions. That is, the videogame awarded points based on participants' performance. For each correct decision, participants received points, and for each mistake they were penalized with a point deduction. At the end of the experiment, participants were paid according to their total score in the game.

Can social psychology explain this pattern of results? The authors argue that the answer can be found in the accessibility of cultural stereotypes linking African-Americans and violence.

Unconscious Influences

Stereotypic descriptions of what various groups of people are presumably like are a common part of social life. They may be perpetuated by the news media, in advertising, or through other cultural influences.

Prior research by Wittenbrink and his colleagues has shown that such culturally dominant stereotypes can be activated in the brain automatically. This activation is part of the early stages of information processing by which people make sense of the things they encounter in their environment.

In the same way that people use certain features of an object to classify it instantaneously as, for example, a chair, they also quickly classify their social environment based on available cues. The processing is habitual, occurring without any intention or awareness, and it operates very rapidly. For example, in the case of the chair, unless it is a very unusual looking chair, people do not consciously have to search for information in order to classify it accordingly. Instead, this classification, and the inferences of the object's characteristics implied by the classification, are made effortlessly, without deliberation, and are readily available. They are activated automatically. The classification of people and the activation of related associations occur in the same fashion.

Wittenbrink notes that in principle, people's ability to quickly activate relevant information and to readily understand what a particular thing is and how to respond to it can be quite useful. In fact, people would not be able to function otherwise. However, there are times when this automatic activation can be dysfunctional because the activated information is deceptive.

The automatic activation of cultural stereotypes can be misleading in this way, because it can influence behavior even when people reject the stereotype as inaccurate or irrelevant to a particular decision. Such influences are particularly likely to occur in situations where a person cannot correct an automatic response with the input from objective information-either because they do not have enough time to consider this information, or because objective information is not readily available.

"What we are studying is a basic feature of how the brain automatically interprets information that we encounter in our social environment, and how these mechanisms impact decision making," says Wittenbrink.

In the videogame, anyone can potentially determine whether the target is actually holding a gun if given enough time, but when given less than a second to respond, the cultural stereotype which associates African-Americans with violence automatically impacts the participant's response.

Not Limited to Race

As suggested by this research, cultural stereotypes can have effects that are truly unintended. Participants in the videogame experiments were motivated to make accurate decisions, and theoretically the ethnicity of the target should have been irrelevant. Nevertheless, the participants, even those who are African-American, could not prevent the cultural stereotype from influencing their decisions.

Although the experiments document these unintended influences in a very specific context where life and death decisions are involved, they demonstrate a much more general effect of cultural stereotypes on judgment and behavior. Cultural stereotypes about African-Americans are not limited to issues of violence, but include other attributes. Moreover, pervasive cultural stereotypes also extend to other ethnic groups, and exist for other social categories such as gender, or nationality. To the extent that any of these stereotypes are well learned, they can have similar unintended influences.

"The basic effect that cultural stereotypes can inadvertently, and without our knowledge, influence behaviors and appraisals is relevant to many everyday situations, including job interviews, meetings with clients, or interactions with colleagues," says Wittenbrink.

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