Thanks in part to the work of Hanns Scharff and a slew of studies on interrogation techniques, we know it's best to be genuinely friendly no matter who you're trying to get information out of.

Tracer fire on the Finnish-Soviet border during the Winter War. (Photo: Public Domain)

The downed World War II fighter pilot had little reason to be wary. Thus far, his German interrogator had seemed uninterested in extracting military intelligence, and had acted with genuine kindness. He made friendly conversation, shared some of his wife’s delicious baked goods, and took the pilot out for a lovely stroll in the German countryside. So when the interrogator erroneously suggested that a chemical shortage was responsible for American tracer bullets leaving white rather than red smoke, the pilot quickly corrected him with the information German commanders sought. No, there was no chemical shortage; the white smoke was supposed to signal to pilots that they would soon be out of ammunition.

The man prying the information loose was Hanns Scharff, and as Raymond Tolliver chronicles in The Interrogator: The Story of Hanns Joachim Scharff, Master Interrogator of the Luftwaffe, Scharff’s unparalleled success did not come from confrontation or threats, but from simply being nice. With the morality and efficacy of interrogation practices coming under increasing scrutiny, Scharff’s techniques—and questions about the extent to which they work—are taking on greater significance.

The fact that Scharff is even mentioned in criminal justice circles is a historical anomaly. Not only was he never meant be an interrogator, he was never meant to be in the German military at all. In the decade leading up to the war Scharff worked as a businessman in Johannesburg, where he lived with his British wife and two kids. Not exactly a portrait of the threatening Axis enemy Captain America was created to battle.

War broke out while Scharff was vacationing in his native Germany. Unable to leave the country, he was eventually drafted into the army. He was destined for the front lines in Russia when his wife talked her way into a general’s office and managed to get Scharff transferred to a unit of interpreters. After a string of additional transfers and coincidences, the last of which was a plane crash that killed his two superiors, Scharff found himself as the lead interrogator for Allied fighter pilots who went down over France and Germany. As a lowly assistant Scharff once saw a prisoner being mistreated, and he vowed to do things differently if he were ever in charge. That core principle was the basis for a strategy so effective a prisoner once quipped that Scharff “could get a confession of infidelity from a Nun.”

There is strong anecdotal evidence of Scharff’s kindness and ability to get what he wanted—in one instance he may have saved the lives of a group of American pilots by persuading the SS to exonerate them from war crime accusations—but researchers have only recently begun systematically testing his techniques to determine if they are actually more effective.

The bulk of the research on Scharff’s strategies comes from the lab of Pär Anders Granhag, a psychology professor at the University of Gothenburg in Sweden. In a new study led by Simon Oleszkiewicz, a former student in Granhag’s lab, the “Scharff Technique” was compared with a method know as the “Direct Approach.”

Participants in the experiment were given a story that contained 35 specific pieces of information about a terrorist attack they helped plan—their interrogators knew only a dozen of them—and instructed to say as little as possible while also revealing enough to earn their freedom; they were told that their compensation for participating would reflect their ability to strike this balance. The interrogations were done by phone, and participants had all of the information in front of them during the call. Researchers measured the quantity and accuracy of information that was revealed, and participants were surveyed about the interrogation after the experiment.

The Scharff Technique was defined by four key components: 1) a friendly approach, 2) not pressing for information, 3) the illusion of knowing it all, and 4) the confirmation/disconfirmation tactic. (The latter strategy is when an interrogator presents a claim in the hope that the prisoner will confirm or disconfirm it—it’s what Scharff used to learn about the tracer bullets.) In contrast, the Direct Approach featured direct questions posed in a more businesslike manner. Relative to the Direct Approach, the Scharff Technique interrogators professed a greater understanding of the prisoner’s situation, spent more time describing what they already knew, and probed for five specific pieces of information by making five claims rather than by asking five questions.

The results, which will be published in Law and Human Behavior, revealed that, relative to the Direct Approach, the Scharff Technique elicited more new information and information that was more precise. But given that the Scharff Technique seems better than simple direct questioning, the findings above may not be all that interesting.

What is interesting about Oleszkiewicz’s study is that participants interrogated using the Scharff Technique tended to underestimate how much they divulged, while participants interrogated using the Direct Approach overestimated how much they divulged. This finding mirrored the results of a similar 2013 study led by Granhag and a 2014 study led by Lennart May, a former researcher in Granhag’s lab. The Scharff Technique resulted in more information, and it did so without alerting participants that they were being too chatty.

The research by Granhag’s lab meshes with the findings from a 2013 study (PDF) of 413 interviews involving 58 United Kingdom interrogators and 29 different terror suspects. The study, which was led by the University of Liverpool’s Laurence Alison, found that adaptive interpersonal behavior—being respectful, warm, non-judgmental, etc.—lead to more disclosure, while maladaptive interpersonal behavior—being distrustful, punitive, patronizing, etc.—led to less disclosure.

If Scharff’s techniques are more effective, do modern interrogations reflect their insight? The answer may be closer to yes than Law and Order reruns would have you believe. (That is, if we momentarily ignore the how-dare-you-reduce-it-to-a-parenthetical exception of last decade’s U.S. government sanctioned torture.)

In a new study led by the University of Albany’s Allison Redlich, 152 interrogators, largely drawn from the FBI, U.S. military, state or local police, and the Department of Homeland Security, reported on the techniques they most frequently used as well as they techniques they believed were most effective. Redlich divided 67 different techniques into six domains: rapport and relationship building, context manipulation, emotion provocation, confrontation/competition, collaboration, and presentation of evidence. She found that, compared to confrontational techniques, rapport and relationship building were used more frequently and believed to be more effective. Overall, Redlich’s findings highlight the success of interrogators who understand the importance of friendliness.

The section on intelligence gathering operations in the official U.S. Army Field Manual (PDF), which was last updated in 2006, also stresses the importance of building a friendly rapport with prisoners. While seemingly outdated practices like “Mutt and Jeff”—more commonly known as “good cop, bad cop”—may still be used with special permission, the manual states that “in most cases, either initially or after the interrogation source has begun answering questions, the HUMINT [Human Intelligence] collector will adopt a more relaxed or even sympathetic posture.... The HUMINT collector must control his temper at all times.”

There is some evidence that more confrontational tactics remain popular, however. In a 2010 whitepaper on police-induced confessions (PDF), Saul Kassin of Williams College reported that the most influential approach is the Reid Technique, which is a set of tactics that may include isolating the suspect, confronting him or her with allegations that may or may not be true, and refusing to accept alibis or denials. Similarly, in a 2007 study (PDF), Kassin found that isolating prisoners from friends and family—a tactic Redlich considered confrontational—was the most popular strategy among a sample of 631 police investigators.

Nevertheless, from 30,000 feet, recent history suggests that interrogators are moving closer to the friendly tactics pioneered by Scharff. Perhaps the deeper question is whether this reflects a broader societal shift toward niceness, not just on the scale of global moral progress, but in terms of the types of quotidian interactions somebody might have with a barista or a cab driver.

In the late 1970s, University of Michigan political scientist Robert Axelrod invited people to write computer programs that would compete against each other in a prisoner’s dilemma tournament. Programs that chose to cooperate would benefit only if the program they were partnered with also chose to cooperate. Axelrod hoped that the winners who emerged from these repeated interactions would reveal something about the evolution of cooperation. In the end, a simple tit-for-tat program won the tournament. When encountering an unfamiliar opponent, the program initially chose to cooperate. On the second meeting, the program mirrored the behavior of its opponent in the first meeting. The effectiveness of a tit-for-tat strategy whose default was cooperation showed the power of an initial decision to act friendly.

If we include virtual interactions, the range of people a person interacts with each day continues to grow. This essentially means that the number of opportunities to “simulate” strategies for interacting with others continues to grow. If being nice is the winning strategy in modern society, then the increasing number of interactions will increase the speed at which people “learn” to adopt this strategy.

If you’re looking to get information—whether it’s from a co-worker, a partner, or your investor friend who works for the Senate Finance Committee—it’s best to be genuinely friendly. That strategy paid off for Scharff both during and after the war. Though his wife left him, he eventually immigrated to the United States, married an American, and had a successful career as a mosaic artist. One of Scharff’s works fittingly rests in a place known for spreading the gospel of camaraderie between those with stark differences: the Magic Kingdom Castle at Disney World.