One of the most challenging aspects of discrimination complaint investigations (and really all investigations into workplace misconduct) is determining how truthful the participating parties are during administrative or investigative interviews. Assessing credibility is an important part of discrimination complaint investigations in particular because there is often an absence of direct evidence in such cases. Reliable deception detection has been historically fraught, and the research demonstrates that even seasoned investigators only perform slightly better than guessing in accurately detecting lies.[1] Some believe non-verbal behaviors are reliable “tells.” Again, however, the research suggests that behaviors such as gaze aversion, fidgeting, and nervousness are less than trustworthy indicators because there is wide individual and cultural variability in such displays.[2] There are no universal non-verbal cues that will indicate deception for all individuals in all situations. It is generally a mistake, therefore, to rely on one’s intuition or non-verbal cues to make credibility judgments.

Nevertheless, assessments of truthfulness must be made, especially in the presence of conflicting statements or other evidence. What is the smart investigator to do, then, to assess the credibility of the employees taking part in a discrimination investigation? The savvy investigator evaluates many different sources of information to assess the credibility of interviewees. The following list describes the U.S. Equal Employment Opportunity Commission sources of information you may consider when making credibility judgments[3]:

  • Behavioral Changes - Instead of looking for specific behavioral cues like “shifty eyes,” look for apparent changes in behavior based on the topic of conversation. In addition to helping to put the interviewee at ease, spending some time building rapport around benign topics will allow you the opportunity to observe any changes in behavior when your questioning shifts to more sensitive subject matter.
  • Consistency of Statements (Internally and Externally) - Pay attention to the details offered by witnesses, and follow up on any inconsistencies. If they do not offer a sufficient resolution to the inconsistencies, allow that information to inform your assessment as to the truthfulness of their statements. Compare witness statements to other evidence, and investigate those discrepancies as well. Ultimately, you are looking for corroboration and cross-verification of key evidence.
  • Plausibility - Evaluate the extent to which the explanations or statements offered by the witness make sense. Are such statements inherently believable, or do they seem to be “a stretch?”
  • Motive to Falsify - Consider whether the person being interviewed has a reason to offer deceptive statements. This is particularly true for anyone accused of engaging in discriminatory behavior.
  • History - Does the accused party have a history of engaging in discriminatory acts? Does the reporting employee have a history of making frivolous complaints? You will want to be sure you are knowledgeable of any pertinent history related to the involved parties that may inform your assessment.

Ultimately, absent of any objective verifying information, your assessment of credibility will be a subjective one. Your task will be to use information such as that described above to derive a reasonable conclusion regarding witness credibility. In addition, it is generally good practice to consistently document such assessments and the factors that influenced them.

Contact Natalie Lynch for more information about effectively conducting employment discrimination investigations.

Cite this article: Lee, L. M. (2016). Assessing credibility: A fool’s errand? Available:


[1] Bond, C. F. & DePaulo, B. M. (2006). Accuracy of deception judgments. Personality and Social Psychology Review, 10(3), 214–234. doi: 10.1207/s15327957pspr1003_2

[2] Burgoon, J. K. & Levine, T. R. (2010). Advances in deception detection. In S. W. Smith & S. R. Wilson (Eds.), New directions in interpersonal communication research (pp. 201–220). Los Angeles: Sage.

[3] U.S. Equal Employment Opportunity Commission. (1999). Enforcement guidance on vicarious employer liability for unlawful harassment by supervisors. Retrieved from