They might look smart, but still think stupid.
One problem that human lie detectors have is that as they gain experience, they gain more confidence... but they don't get any better at detecting liars:
We’ve all been lied to, and most of us have a high opinion of our ability to tell a lie from the truth. Yet research repeatedly shows that confidence to be misplaced and that judges, customs inspectors, and yes, detectives, make lousy lie detectors.Read: Human Lie Detectors: The Death of the Dead Giveaway, Pacific Standard>>
Those in law enforcement are trained to “read” body language, affect, facial expressions, mannerisms, and ways of speaking, and to believe that they can trust their gut. They learn that if a suspect averts their gaze, touches their nose, chews a fingernail, strokes the back of their head, slouches or fidgets, they are likely lying and thus, guilty.
Virtually all scientific research finds this mindset is counterproductive and even lowers the accuracy of judgments. People under stress—being wrongly accused certainly qualifies—can behave in ways impossible to distinguish from those who are lying. Yet the accused may be convicted in the court of public opinion—or worse—in large part because they don’t react to tragedy or the loss of a loved one as others want them to or expect.
Six Everlasting Truths about Deception. Lying is easy; detecting lies is hard. Psychology Today>>
Image stolen from Jay Pinkerton>>