A WWII-era piece on interrogation (despite the use of the term "interpreter" in the title) by a Marine Major in the Pacific theater:
Suggestions for Japanese Interpreters Based on Work in the Field
, 17 Jul 43
First of all I wish to say that every interpreter (I like the word "interviewer" better, for any really efficient interpreter is first and last an interviewer) must be himself. He should not and cannot try to copy or imitate somebody else, or, in the words of the Japanese proverb, he will be like the crow trying to imitate the cormorant catching fish and drowning in the attempt ("U no mane suru karasu mizu ni oboreru"). But of course it goes without saying that the interpreter should be open to suggestions and should be a student of best methods. But his work will be based primarily upon his own character, his own experience, and his own temperament. These three things are of prime importance; strange as it may seem to say so, I think the first and the last are the most important of the three. Based on these three things, he will gradually work out a technique of his own, - his very own, just as a man does in making love to a woman! The comparison is not merely a flip bon mot; the interviewer should be a real wooer!
What I have to say concretely is divided into two sections: (1) The attitude of the interpreter towards his prisoner; (2) His knowledge and use of the language......
Major Moran's 1943 memo, despite its age and brevity (just eight pages), remains an insightful and useful read for those interested in interrogation methodology and techniques. As seen in the quote above, Moran focuses on two aspects of interrogation (although he never uses that term in the memo): the attitude of the interrogator towards the source, and the interrogator's knowledge and use of language.
As he states, the attitude of the interrogator is of primary importance and is critical to success or failure in the interrogation. The discussion of attitude in this memorandum is specifically focused on Japanese prisoners of war, but this is worth the time no matter what area of interrogation the reader may work or have an interest in. Considerations of environment, culture, physical condition of the source and the nature of the interrogator's character as perceived by the source are critically important to any interrogation.
Dividing and defining language used in the conduct of interrogation into "knowledge" and "use" is an important point for interrogators to consider, even when working in their native language, but obviously more so when working in a second language. Regarding "knowledge" of language, Moran stresses the importance of idiomatic language, as opposed to technical vocabulary, for rapidly developing rapport and initiating conversation with the source. (Oreste Pinto is another WWII interrogator who has written useful material on the understanding of language in interrogation)
As for "use" of language, Moran discusses in a simple and general manner concepts of rapport, cognition, questioning methodology and leveraging aspects of culture in questioning. He also describes the difference between empathy and sympathy, and the dangers of the latter, although not in such precise terms.