Can you ever be absolutely certain if someone is either telling the truth or lying? A recent story on human lie detectors featured the accurate subtitle, “The death of the dead give-away.” Often, we assume that a particular facial twitch or manner of speaking is an infallible giveaway that someone is lying. While there are some clues to deception, they are probabilistic associations, not dead give-aways.
Based on my research, here are 5 truths about lie detection:
While many sectors would love to see perfect lie-detection—in the pursuit of alleged murderers, for instance—perfect lie-detection for every kind of lie in every situation would be inconvenient. Would you really want other people to know—always—how you really feel, regardless of what you say about how you feel? Would you want them to be able to discern the truth about all of the facts of your life? Or conversely, would you want to know what other people really do think of you, all of the time and in every situation?
Many lies are heinous and cannot be justified in any way. But beware of the urge to find the truth, the whole truth, and nothing but the truth, always and forever. The cliché, “Be careful what you wish for,” was written for yearnings such as that one.
Notes: My books on deception include Behind the Door of Deceit: Understanding the Biggest Liars in Our Lives; The Hows and Whys of Lies; The Lies We Tell and the Clues We Miss: Professional Papers; and Is Anyone Really Good at Detecting Lies: Professional Papers (co-authored with Charles F. Bond Jr.). They are all available in print or as e-books. Other links are here.