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Why We See Guns That Aren't There.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


When George Zimmerman saw Trayvon Martin walking down the street in Sanford, Florida, he quickly assumed that the Black, hoodie-clad teenager was carrying a weapon. In Zimmerman's own words, "He's got his hand in his waistband. And he's a black male. ... Something's wrong with him. Yup, he's coming to check me out. He's got something in his hands. I don't know what his deal is. ... These assholes, they always get away."1

Although many still debate the subsequent sequence of events and whether or not Zimmerman was acting in self-defense, the incident ended with Zimmerman pulling out his own gun and fatally shooting Martin. Who, ultimately, was unarmed.2

The fact that George Zimmerman assumed so quickly that Trayvon Martin was reaching for a weapon smacks of obvious racial prejudice. It ended up being a tragic assumption that led to the death of an innocent young student, who had simply been in the wrong place at the wrong time. But was this mistake unique to Zimmerman in particular? Unfortunately, a 2002 study by psychologist Joshua Correll suggests that your average, run-of-the-mill college student might have made a similar snap judgment.


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If you had a split second to decide whether or not to shoot someone in front of you, do you think you would shoot? Do you think the other person’s skin color would matter? To test the idea that people might respond differently to Black and White targets, Correll and colleagues designed a first-person shooting game to test how ordinary people might make the split-second decision to either shoot or not shoot a potentially armed target, otherwise known as the Police Officer’s Dilemma.

Groups of college students were told that a series of people would come on the screen in front of them and would either be holding a gun or a neutral object, like a wallet, aluminum can, or cell phone. If the participants correctly shot an armed target, they would receive 10 points; if they correctly refrained from shooting an unarmed target, they would receive 5 points. Shooting an unarmed target deducted 20 points, and not shooting an armed target – the most potentially dangerous outcome for a real police officer on the streets – would result in the harshest penalty of all, a 40-point deduction.

As each target appeared on screen, participants had to decide as quickly as possible if the target was holding a gun or a harmless object by pushing buttons labeled either “Shoot” or “Don’t Shoot." Unbeknownst to participants, the researchers had manipulated one critical feature of the targets – some of the targets were White, and some of the targets were Black.

The researchers ultimately found a clear case of what they termed shooter bias. Over a series of four studies, participants were faster to (correctly) shoot an armed target when he was Black, and faster to (correctly) decide not to shoot an unarmed target when he was White. But the truly interesting (and tragic) finding emerges when studying the cases where people accidentally chose to shoot targets who were holding wallets or cell phones. As it turns out, the participants were consistently more likely to accidentally shoot an unarmed target when he was Black.

Surely this must be influenced by racism, thought the researchers. After all, it would certainly make sense that racist people would be more likely to jump to the conclusion that Black people are armed. Wouldn’t non-racist people be more likely to disregard the color of the target’s skin when making judgments? Wouldn’t non-racist people – especially those who are well aware of the negative stereotypes towards Black people in American culture, and those who consciously try to fight against prejudice in their everyday lives – be more forgiving on the trigger?

Unfortunately, that hypothesis could not be further from the truth. First of all, no matter how explicitly racist the participants were (or were not), they were equally likely to shoot unarmed Black targets; self-reported and implicitly measured racism did not have any relation to shooter bias. However, one thing did predict performance on the task – the participants’ level of awareness that there is prejudice towards Black people in American society, even if the participant adamantly did not support those stereotypes. Simply being highly aware of prejudice in the world, even if you don’t agree with, support, or like that prejudice, makes it more likely that you might make the fateful mistake of shooting an unarmed target when making split-second decisions in uncertain conditions. The more aware you are of cultural stereotypes, the more likely you are to make a biased mistake.

Dismissing what happened to Trayvon Martin by pinning the entire tragedy on Zimmerman’s racism and failing to acknowledge the cultural forces that may have been at work on his behavior is a dismissal of years of social psychological research that has tried over and over again to hammer in the importance of situational forces. Correll’s research demonstrated that everyone – even an upstanding college undergraduate lacking any explicit or implicit racial prejudice – is vulnerable to making racially biased decisions, particularly under the split-second pressures of the Police Officer’s Dilemma. Did racism motivate George Zimmerman’s actions against Trayvon Martin? Probably. But does a person have to be racist to make the same split-second judgment? No.

When you grow up in a culture that endorses certain stereotypes, they become ingrained in your cultural knowledge. Even if you don’t actually endorse those stereotypes, they can still impact your behavior in horrifying ways. A study from the 1940s demonstrated that young Black girls often preferred to play with White-skinned dolls over Black-skinned dolls, presumably because they were growing up in a culture endorsing the idea that White = Beautiful. And importantly, when the “shooting game” task was given to Black participants, they were just as likely to accidentally shoot unarmed Black targets as the White participants were.

At the end of the day, it’s not always about whether or not you are racist, or whether or not you think that Black people are violent. Cultural stereotypes can become automatically activated and applied to our behaviors even when we don’t actually endorse them. The sheer knowledge that these stereotypes exist can be enough to influence our judgments, especially when it comes to split-second decisions that often rely on heuristics and automatic mental associations. Because of cultural stereotypes, the shooters in Correll’s games had a lower threshold for when they would decide it was OK to shoot at Black targets, even though most of them probably could not have told you that this was happening, and most of them would have been appalled to discover that they had unknowingly acted on these implicit biases.

Personalities and racial attitudes are important, yes. But cultural and situational forces are important too.

This is certainly not meant to excuse Zimmerman's actions, nor is it meant to say that anyone else in that situation would have shot Trayvon Martin. After all, we now know that Zimmerman had called 911 an alarming number of times in the past, simply to report the presence of Black people that he felt looked “suspicious.” We also know that Zimmerman followed Martin even when the police had explicitly instructed him not to do so. There are a lot of complicating factors in this case. I was not there, and I can only write about this incident with the knowledge that I have gleaned as an outside observer who has read the police reports and watched media coverage of the incident and subsequent trial.

However, writing off this tragedy to the uniquely prejudiced actions of Zimmerman himself ignores a much deeper problem that merits all of our consideration:

What are the consequences of growing up in a world that is planting the seeds of racism deep within our minds every day?


1. These quotes are taken from the transcript of George Zimmerman's call to 911, which can be found here. Ellipses indicate where content was omitted, mostly about how old Martin looked and what he was wearing.

2. As an astute commenter notes, this is not a perfect example of the Police Officer's Dilemma as Zimmerman did not shoot Martin because he thought that Martin was reaching for a gun. In fact, the infamous case of Amadou Diallo would probably be a more appropriate example of this particular scenario, as the shooting in this case actually did involve Diallo reaching for a wallet and the police officers mistakenly assuming that he was reaching for a gun. However, I do believe it is clear that snap judgments contributed to why Zimmerman chose to follow Martin & why there was ultimately a confrontation that ended in Martin's death; without these snap judgments, Zimmerman likely would not have noticed Martin reaching for his waistband or thought that his presence was "suspicious" in the first place. Even if Zimmerman was ultimately acting in self-defense, the confrontation and altercation did unambiguously occur because of an initial suspicion on Zimmerman's part -- a suspicion likely due (at least in part) to the implicit cultural associations discussed in this post. I have slightly edited this post from its original form to make this distinction clearer.

Note #1: Psychological aspects of the Trayvon Martin case have been covered very well elsewhere in the blogosphere as well. Some particularly good examples are here and here.

Note #2: Due to the sensitive nature of this topic, the comment section will be more heavily moderated than usual. Please be aware that comments will not be allowed if they contain anything that can be construed as hate speech, or if they defame the author of this post, Trayvon Martin, George Zimmerman, Martin's family, Zimmerman's family, the jurors in this case, or anyone else involved. Threats and/or personal insults will not be tolerated.


Correll, J., Park, B., Judd, C.M., & Wittenbrink, B. (2002). The police officer’s dilemma: Using ethnicity to disambiguate potentially threatening individuals. Journal of Personality and Social Psychology, 83 (6), 1314-29 PMID: 12500813

Correll, J., Wittenbrink, B., Park, B., Judd, C., & Goyle, A. (2011). Dangerous enough: Moderating racial bias with contextual threat cues. Journal of Experimental Social Psychology, 47 (1), 184-189 DOI: 10.1016/j.jesp.2010.08.017

Image Credits:

Photograph of Trayvon Martin released by his family via Wikipedia; available under free use.

A slightly different version of this piece was posted on the Scientific American Guest Blog in March 2012. You can read the original post by clicking the From The Archives icon on the left.

Melanie Tannenbaum is a freelance writer and science communications consultant currently living in the Bay Area. She received her Ph.D. in social psychology from the University of Illinois at Urbana-Champaign in 2015, where her research focused on the science of persuasion and motivation regarding political, environmental, and health-related behavior. For more info, see her personal website.

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