Cops show is heavily edited; police officers simply aren’t that busy.) Johnson watched 480 old episodes of Cops. He was looking for interactions between a police officer and a citizen in which the citizen was on camera, from the waist up, for at least sixty seconds. He found 452 segments like that. Then he divided the segments into “innocent” and “suspect,” based on the information provided in the show. Was this the mother, child in arms, whose home had just been burglarized? Or was this the teenager who ran the instant he saw the police, and was found with the woman’s jewelry in his backpack? Then he subdivided his collection of clips one more time by race—white, black, and Hispanic.
It should be pointed out that there is a small mountain of research on so-called demeanor cues. But Johnson’s study is special because it was not done in a college psychology lab. It’s real life.
Let’s start with what many police officers believe to be the most important demeanor cue—eye contact. The Reid Technique’s training manual—the most widely used guide for law enforcement—is clear on this: People who are lying look away. Truthful suspects maintain eye contact.
So what does Johnson find when he examines this idea in the light of real-world interactions on Cops? Are the innocent more likely to look an officer in the eye than the guilty?
Johnson calculated the total number of seconds of eye contact per minute of footage.
Black people who are perfectly innocent are actually less likely to look police in the eye than black people who are suspected of a crime. Now let’s look at white people:
The first thing to note here is that Caucasians on Cops, as a group, look police officers in the eye far more than black people do. In fact, whites suspected of a crime spend the most time, of all four groups, looking the police officer in the eye. If you use gaze aversion as a cue to interpret someone’s credibility, you’re going to be a lot more suspicious of black people than white people. Far worse, you’re going to be most suspicious of all of perfectly innocent African Americans.
OK. Let’s look at facial expressions. The Reid Technique teaches police officers that facial expressions can provide meaningful clues to a suspect’s inner state. Have I been found out? Am I about to be found out? As the manual states:
“The mere fact of variation of expressions may be suggestive of untruthfulness, where the lack of such a variation may be suggestive of truthfulness” (Reid et al., Essentials of the Reid Technique, p. 99).
This is a version of the common idea that when someone is guilty or being evasive, they smile a lot. Surveys of police officers show that people in law enforcement are very attuned to “frequent smiling” as a sign that something is awry. To use the language of poker, it’s considered a “tell.” Here is Johnson’s Cops analysis of smiling. This time I’ve included Johnson’s data on Hispanics as well.
Once again, the rule of thumb relied upon by many police officers has it exactly backward. The people who smile the most are innocent African Americans. The people who smile the least are Hispanic suspects. The only reasonable conclusion from that chart is that black people, when they are on Cops, smile a lot, white people smile a little bit less, and Hispanic people don’t smile much at all.
Let’s do one more: halting speech. If someone is trying to explain themselves, and they keep nervously stopping and starting, we take that as a sign of evasion or deception. Right? So what does the Cops data say?
The African American suspects speak fluidly. The innocent Hispanics are hemming and hawing nervously. If you do what the Reid manual says, you’ll lock up innocent Hispanics and be fooled by guilty African Americans.
Does this mean we simply need a better, more specific set of interpretation rules for police officers? Watch out for the smooth-talking black guy. White people who don’t smile are up to no good. No! That doesn’t work either, because of the enormous variability Johnson uncovered.
Take a look, for example, at the range of responses that make up those averages. Eye contact for innocent African Americans ranged from 7 seconds to 49.41 seconds. There are innocent black people who almost never make eye contact, and innocent black people who make lots of eye contact. The range for smiling for innocent black people is 0 to 13.34. There are innocent black people who smile a