Sommers, Roseanna and Bohns, Vanessa K., The Voluntariness of Voluntary Consent: Consent Searches and the Psychology of Compliance (April 10, 2019). Yale Law Journal, Vol. 128, No. 7, 2019. Available at SSRN

“Consent-based searches are by far the most ubiquitous form of search undertaken by police. A key legal inquiry in these cases is whether consent was granted voluntarily. This Essay suggests that fact finders’ assessments of voluntariness are likely to be impaired by a systematic bias in social perception. Fact finders are likely to underappreciate the degree to which suspects feel pressure to comply with police officers’ requests to perform searches.

In two preregistered laboratory studies, we approached a total of 209 participants (“Experiencers”) with a highly intrusive request: to unlock their password-protected smartphones and hand them over to an experimenter to search through while they waited in another room. A sepa- rate 194 participants (“Forecasters”) were brought into the lab and asked whether a reasonable person would agree to the same request if hypothetically approached by the same researcher. Both groups then reported how free they felt, or would feel, to refuse the request.Study 1 found that whereas most Forecasters believed a reasonable person would refuse the experimenter’s request, most Experiencers—100 out of 103 people—promptly unlocked their phones and handed them over. Moreover, Experiencers reported feeling significantly less free to refuse than did Forecasters contemplating the same situation hypothetically.Study 2 tested an intervention modeled after a commonly proposed reform of consent searches, in which the experimenter explicitly advises participants that they have the right to with- hold consent. We found that this advisory did not significantly reduce compliance rates or make Experiencers feel more free to say no. At the same time, the gap between Experiencers and Forecasters remained significant. These findings suggest that decision makers judging the voluntariness of consent consistently underestimate the pressure to comply with intrusive requests. This is problematic because it indicates that a key justification for suspicionless consent searches—that they are voluntary—relies on an assessment that is subject to bias. The results thus provide support to critics who would like to see consent searches banned or curtailed, as they have been in several states…”