Would You Let the Police Search Your Phone?

We are much more likely to give consent than we think.

Roseanna Sommers and

Dr. Sommers is a lecturer at the University of Chicago Law School. Dr. Bohns is an associate professor of organizational behavior at the School of Industrial and Labor Relations at Cornell.

Credit...Mark Pernice

Law enforcement officers on the doorstep threatening to “come back with a warrant” is a cliché of police procedural dramas. Things are much less dramatic in real life: The officers ask if they can take a look around, and the civilians say yes without putting up a fight.

A key question in so-called consent -search cases is why people so readily agree to allow intrusions into their privacy. The answer, as we argue in a forthcoming article in The Yale Law Journal, is that psychologically, it’s much harder to refuse consent than it seems. The degree of pressure needed to get people to comply is shockingly minimal — and our ability to recognize this fact is limited.

The legal standard for whether a consent search is voluntary — and thus whether any contraband police discover is admissible in court — is whether a reasonable person would have felt free to refuse the officers’ request. Courts tend to judge the voluntariness of consent by looking for clear markers of coercion. Did the officer phrase the request as a demand, instead of a question? Were weapons drawn? If not, the search is likely to be deemed voluntary.

But this approach misunderstands the psychology of compliance. It takes much less pressure than it seems to secure people’s acquiescence. Police don’t need to use weapons to get people to accede to their requests; they just need to ask. Our research shows that a simple, polite face-to-face request is harder to refuse than we think.

To test how the psychology of compliance operates, we recruited hundreds of participants to the lab. We approached half of them with a polite but audacious request: “Before we begin the study, can you please unlock your phone and hand it to me? I’ll just need to take your phone outside of the room for a moment to check for some things.”

For the other half, we asked what a reasonable person would do if hypothetically approached by the same experimenter with the same request.

Our control group, who merely imagined the interaction, said that most people would refuse to hand over the phone: Only 14 percent thought a reasonable person would let us search the phone, and only 28 percent said they would yield their phone to a stranger. But when we actually approached people, 97 percent handed over their phone.

In addition, these participants reported feeling significantly more pressured to comply than the control group imagined feeling. The fact is, saying no is more difficult, and rarer, than we realize. We believe this same dynamic plays out the in the law surrounding consent searches.

To be sure, saying no to a police officer is different from a saying no to an experimenter in a laboratory study. So we also tested whether people underestimate the pressure to comply with the police as well.

We recruited a separate group of survey respondents and offered them a monetary bonus if they could predict how often drivers grant consent when stopped by the police. According to traffic data, upward of 90 percent of drivers say yes when the police ask to search their car. But our survey respondents’ average guess was far lower: They thought that only about 65 percent of drivers say yes. Again, people vastly understated compliance.

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This tendency to underappreciate the power of social influence is one of the most enduring and important findings in all of social psychology. In Stanley Milgram’s famous studies on obedience, for instance, research participants were willing to heed an experimenter’s instructions to administer dangerous electric shocks to an innocent, protesting victim.

Mr. Milgram showed that normal people would commit violent acts — not because they were sadists, but because they were loath to disobey an authority figure’s directives. This was a result that no one, including expert psychologists, expected.

Critics of consent searches have also been approaching the issue in the wrong way. Groups like the American Civil Liberties Union have focused on advocating that the police be required to notify citizens of their right to refuse consent, much as the police are required to read custodial suspects their Miranda rights. But this is unlikely to address the psychological factors at play.

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In another study, we tested what happens when we tell people they “have the right to refuse”the request to search their phone. We found that this notification altered people’s beliefs about the consequences of refusal, but it did not change how free they felt to refuse. Nor did it reduce the rates at which they handed over their phone to us — a result consistent with previous studies that have found negligible effects of Miranda warnings on the rates at which suspects confess to crimes.

The failure of “know your rights” interventions makes sense if you think about the psychology behind police-citizen interactions. Telling people about their rights addresses information deficits, but the real reason people comply is social, not informational. The social imperatives to comply with a police officer’s request persist even when people are properly informed of their rights or given a consent form to sign — or just asked politely.

Roseanna Sommers is a lecturer at the University of Chicago Law School. Vanessa K. Bohns in an associate professor of organizational behavior at the School of Industrial and Labor Relations at Cornell.

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