A meta‐analytic review of experimental tests of the interrogation technique of Hanns Joachim Scharff

Abstract

Summary Hanns Scharff, an interrogator during the Second World War, was known for his remarkable effectiveness at collecting intelligence from prisoners of war using a friendly, conversational approach in which he led the prisoners to unknowingly reveal the information he wanted. In the last decade, psychologists have produced a body of experimental studies testing the effectiveness of Scharff's interrogation technique. Here, I provide a meta‐analytic review of that experimental research. The existing data supports the conclusions that the present conceptualization of Scharff's technique is effective at eliciting more new information, leading people to perceive the interviewer as more knowledgeable, and inducing people to underestimate how much information they have revealed. However, numerous unanswered questions and challenges for this program of research remain. For example, future research may benefit from examining unaddressed elements of the methods Scharff used in the field. Research would also benefit from the development of measures that more clearly correspond to practical outcomes.

“What works?” Systematic reviews and meta‐analyses of the investigative interviewing research literature

“…Several suspect interviewing techniques that can facilitate credibility assessments are then evaluated, including the timing of evidence disclosure (Oleszkiewicz & Watson, 2021) and the Scharff interrogation technique (Luke, 2021). Recent research has examined both strategic and tactical approaches to the disclosure of evidence – tactics that are believed to facilitate statement‐evidence inconsistencies from guilty versus innocent suspects and to potentially facilitate the disclosure of novel information.…”

How Intelligence Interviewees Mentally Identify Relevant Information

“…These instructions allow research studies to mimic the typical dilemma interviewees face in actual intelligence interviews (see, e.g., Soufan, 2011). A recent review indicates that when responding to direct questions, the mock interviewee role leads participants to disclose some but not all the information they possess (Luke, 2020). We can infer from this finding that interviewees implement a honing process, at least intuitively, to determine the relevant information at their disposal.…”

Milestones and signposts in the science of investigative interviewing

“…Anecdotes, however, are insufficient in identifying causal relationships than can inform practice. A body of research has now demonstrated the effectiveness of what has been labeled “the Scharff technique.” As reported in this issue, the full conceptualization of the technique requires further research to address research questions that remain unanswered (see Luke, 2021).…”