Historically human beings are very bad at spotting deception failing on average 50% or more the time to identify lies. Unfortunately, investigative interviewers and  professionals in many other disciplines also have the same poor performance based on numerous research studies.  One of the major contributing factors is that most of us make our assessments about whether a person is being truthful or deceptive based on our �gut feelings� and other undefined symptoms.  Such intuitive assessments have always proven themselves to be inconsistent and unreliable.  When an investigative interviewer focuses their analysis on more reliable documented verbal and nonverbal cues, their accuracy dramatically improves.

An �intuitive� analysis of a subject frequently is characterized by comments such as �I think he�s lying� or �I know he�s hiding something.�   When you ask the observer what specific behaviors make them believe the person is deceptive you often get answers such as �I can tell,� �You just know� and they fail to identify any reliable cues.  When they do cite verbal or nonverbal cues those that are mentioned as deception markers are more often than not are just signs of stress or incriminating stress cues and fail
to isolate lies.

A reliable analytical diagnosis of behavior focuses on specific questions or issues and clearly defined behavior responses by the subject.  These analyses are characterized by comments including terms such as �clusters�, �timing�, �consistent�, �change� and �constant.�  In these cases the interviewer � observer can be very specific about a subject�s deception and can name the particular behaviors.
The behaviors mentioned will be cues identified as �denial�, �aversion�, �negation�, �contradiction�, �unclear thought line� or �performance.�

The danger of making an �intuitive� diagnosis is that they are subject to �pre-conceptions� by the interviewer that more often than not results in gross misdiagnosis.  As we�ve discussed in the past the existence of pre-conception on behalf of the interviewer is also most often results in contamination of the interview further compounding the error of the credibility assessment.   The end result of such a
flawed analysis can be wasted time, investigative effort and resources and at worst a case subject to crushing attacks that can be made in defense of the subject in trial and disciplinary proceedings.  An analytical diagnosis requires a lot more effort by the interviewer.  The observer will force themselves to resist making blanket statements about their subject�s lack of honesty without specific behaviors
they have identified to support their conclusions.  Case made with such extensive micro-analysis typical contain better quality information and often other forensic sources that provide confirmation of the subject�s remarks.  These cases are also more likely to survive any challenge of prejudice, flawed analysis, contamination and some cases even false confession.  On what basis are you deciding the
subject is being deceptive � your �gut feelings� or reliable behavioral cues that you can cite on a point-to-point basis? Don�t just tell me your subject is lying � tell me what he or she is lying about and the specific behaviors that have led you to that conclusion.

� 2003 by Stan B. Walters  All Rights Reserved