Intuitive versus Analytical Diagnosis of Credibility

Abstract
Historically, human beings have been poor at detecting deception, often performing at or near chance levels. Unfortunately, investigative interviewers and professionals in many other disciplines have shown the same weakness. One major contributing factor is that many credibility assessments are made on the basis of “gut feelings” and other loosely defined impressions. Such intuitive judgments have repeatedly proven inconsistent and unreliable.

The Problem with Intuitive Judgments
An intuitive analysis of a subject is often reflected in comments such as, “I think he’s lying,” or, “I know he’s hiding something.” When asked what specific behaviors support that conclusion, the observer often responds with statements such as, “I can tell,” or, “You just know,” without identifying any clearly defined basis for the judgment. Even when verbal or behavioral observations are cited, they are often poorly distinguished from stress, discomfort, defensiveness, or other reactions that do not, by themselves, establish deception.

What Analytical Diagnosis
Looks Like A more analytical diagnosis focuses on specific issues, specific statements, and clearly defined response patterns. These assessments are characterized by terms such as timing, consistency, change, contradiction, clarification, and comparison. In these cases, the interviewer-observer is expected to move beyond broad impressions and identify what changed, where it changed, and why that change matters.

The Risk of Preconception and Contamination
The danger of an intuitive diagnosis is that it is highly vulnerable to interviewer preconception. More often than not, preconception leads to misdiagnosis. As discussed previously, preconception can also contaminate the interview itself, compounding the error in credibility assessment. The result may be wasted time, misdirected investigative effort, lost resources, and, at worst, a case vulnerable to serious attack in court or disciplinary proceedings.

From Assumption to Diagnosis
Analytical diagnosis requires more effort from the interviewer. It demands that the observer resist making blanket claims about dishonesty unless they can point to specific statements, response patterns, inconsistencies, or changes that justify further examination. Cases built on that kind of disciplined analysis typically produce better information and are more likely to generate independent confirmation from other sources. They are also more likely to withstand challenges involving prejudice, flawed assessment, contamination, and false confession.

So on what basis are you deciding that a subject is deceptive—gut feeling, or disciplined analysis? Don’t just tell me you think a subject is lying. Tell me what issue concerns you, what specifically changed, and what observable features led you to that conclusion.