Participants in our interviewing courses have lots of questions. Here are some of the most frequently asked.
What is the difference between a deception clue and a mistake? Deception clues are symptoms of the possibility of deception. They can be verbal involving words, vocal involving sounds (or silence), and non-verbal involving body language. Deception clues occur as a function of behavioral change and can manifest themselves during the interviewee's narrative presentation in response to open or closed questions. (Open questions ask what, how, why, could, or would. Closed questions utilize do, is, are, and did.) They're not limited to these two question forms but certainly these are the most common.
While no one deception clue is definitive, when they occur in clusters they can be most telling. A cluster of deception clues involves two or more verbal, vocal, or non-verbal behavioral changes occurring simultaneously. An example of a cluster of deception clues would be: (1) adaptor: bringing a hand to the mouth (2) false supportive: "to tell you the truth" (3) direct reference: "you know" and (4) an equivocating answer. (An example of an equivocating answer would be: Q: Did you go into the vault? A: I am not authorized to go into the vault.)
There could be any number of emotive or environmental factors that bring about an individual change in behavior but the clustering diminishes the probability that deception wasn't the precursor. (For example, if the interviewee became cold during the interview that could cause him to cross his arms but wouldn't affect the use of direct references, the increase in the latency of response, etc.) Nevertheless, the astute interviewer, after identifying the behavioral change cluster will ask an amplifying question - an additional topic-related question to further explore a specific area - after a cluster of deception clues and observe the interviewee as he responds.
Conversely, a mistake will reveal the truth. A deceptive interviewee will only make mistakes when the interviewer has maneuvered him through his question strategy into utilizing falsification (lying) as a means of continuing the deception. As long as the interviewee can deceive by concealment he won't make any mistakes. The complexity of deception via falsification requires that the interviewee remember the asserted lie that he's drawn from his imagination. As the interviewer begins to explore the details about the lie, the deceiver now has to remember his exact lies and when he had lied. The complexity increases diametrically because of the interviewee's need to remember continually fabricated information and provides the possibility that the deceiver inadvertently will say something that reveals the truth. An example of a mistake: a loan officer who had approved some questionable business loans to an individual asserted during the interview that their relationship was strictly of a business nature. However, later in the interview he revealed inadvertently by his response to the interviewer's question that the relationship was more personal.