Last December a Senate Intelligence Committee report revealed how two psychologists were involved in shaping the CIA's “enhanced interrogation” methods, using psychologist Martin Seligman's theory of learned helplessness to justify controversial practices such as waterboarding and sleep deprivation—something Seligman himself has repudiated.* The problem is that in addition to being morally reprehensible, interrogation methods based on force and intimidation don't work.

“Coercive, confrontational methods actually lead to the detainee shutting down,” says psychologist Christian Meissner of Iowa State University, who studies interrogation techniques. “More effective tactics rely on cooperation, which can be facilitated using principles of social influence that we know work very well.”

According to the American Psychological Association, if a psychologist meets certain conditions, chief among them “do no harm,” it is permissible for him or her to aid in interrogations. So is there an ethical way to extract a confession from someone?

To find out, in 2009 President Barack Obama convened the High Value Detainee Interrogation Group (HIG), made up of cognitive and social psychologists and other experts. This winter the HIG, led by Meissner, released its findings in a special issue of Applied Cognitive Psychology. Ethical interrogations are not only possible; their effectiveness is also robustly supported by research.

At the right are some of the HIG's most interesting findings. Though developed for law enforcement, there is no reason to think these strategies will not also work on the mendacious teens, spouses and co-workers in your life if you need to get to the bottom of something.

1. Build rapport. Think of it as just “good cop.” Researchers have found that coming across as empathetic causes interrogation targets to open up more than when the interrogator is cold and accusatory. Many of the other techniques described in the journal depend on having a cooperative target, making this step all the more important. “The first thing you have to do is develop cooperation, rapport,” Meissner says. “Once you have a cooperative person, the question is, How do I get all the info from them that I can?”

2. Fill in the blank. To get that info, instead of asking direct questions, tell your target a story about what he or she did, leading the person to believe you already know what happened. As you provide the narrative, the guilty party will then supply details and corrections. This is called the Scharff technique, named for its developer, Hanns Scharff, a German interrogator during World War II. The technique was shown to elicit more information than direct questioning in a 2014 study. People interrogated using this method also tend to underestimate how much they are sharing.

3. Surprise them. People who are interrogated often know they are under suspicion, so they practice their answers ahead of time. In addition, liars are under high cognitive strain as they try to keep their story straight and at the same time act calm and collected. If you ask them something unexpected, they often stumble when put on the spot—enabling you to catch them in a lie.

4. Ask for the story backward. In contrast to what most people believe, truth tellers are more likely to add details and revise their stories over time, whereas liars tend to keep their stories the same. “Inconsistency is really just a fundamental aspect of the way memory works,” Meissner says. A technique that interrogators use to capitalize on that quirk is called reverse telling—asking people to recall events backward rather than forward in time. This strategy has a double effect: For truth tellers, it makes recall easier—in another HIG study, reverse telling produced twice as many details as did recounting chronologically. For liars, the task becomes harder when put in reverse; they become more likely to simplify the story or contradict themselves.

5. Withhold evidence until the crucial moment. In a study last March, when people were confronted with potential evidence of their wrongdoing early in the interview, they either clammed up and adopted an extremely hostile posture or immediately spilled their guts, depending on the individual. Rather than risking the former, the researchers advised truth seekers to take a middle path, alluding to evidence without making any direct accusations—at least not right away.



*Erratum (4/15/15): This sentence was edited after publication to correct Martin Seligman's name.

