If you need to extract useful information from someone, the best approach may be kindness, according to new research out of Sweden. Specifically, researchers compared a common, "direct" interrogation—where the questions are direct and specific—to the Scharff Technique, named after the highly successful German interrogator Hanns Scharff. He once shared his wife's baked goods and a long stroll with a World War II fighter pilot, reports Pacific Standard magazine; when he claimed that American tracer bullets left a white instead of red smoke due to a chemical shortage, the pilot jumped in to correct him, saying the white smoke was a signal to pilots that they were low on ammo. Thus Scharff was armed with the information he sought. And as the magazine notes, researchers are only now beginning to put his techniques to the test.
In the study, where participants were given a story with 35 details and interrogated by phone, Scharff's approach not only resulted in more (and more precise) information, but those being interrogated thought they gave up less information than they actually had, while those being interrogated directly felt they gave up more than they actually had. Kindness is not the only key ingredient to the Scharff Technique; having a "know-it-all" attitude compels information-disclosing corrections, as in the case of the pilot correcting his "friend." Pacific Standard has more on Scharff, who ended up as a chief interrogator of Allied fighter pilots after an odd series of events.