People Are Horrible (But Confident) Lie Detectors
We are terrible at figuring out if someone is lying to us. Absolutely terrible. Seriously. Terrible.
Here's the catch: We think we are great at it.
This can be a major problem for attorneys who are trying to decide whether their client should testify at trial. People on the jury might use all sorts of problematic strategies to determine the client is lying. Even if the client is telling the truth, jury members may be certain he/she is lying. They will use the client's nonverbal behaviors to assume deception is taking place.
The problem with using nonverbal behaviors to determine the truth from a lie is that nonverbal behaviors do not correlate with lying.
The most popular, and erroneous, belief is that lack of eye contact and averting one's gaze are both signs of lying. Everyone believes that to be true. I have seen people get convicted because they don't make eye contact.
However, research from the last 40 years has consistently shown that lack of eye contact and averting one's gaze has no relationship at all to lying. In fact, the opposite may be true. Many people maintain better eye contact when they are lying.
The same is true of fidgeting--head movements, picking at the hands or face, arm movements, shifting in one's chair--all of these nonverbal behaviors are assumed to predict lying, but they don't.
In addition to being terrible at figuring out whether a person is lying, attorneys also need to worry that jurors will actively seek out nonverbal behaviors that confirm their biases. If a juror thinks the client might be lying, the juror will look for nonverbal behaviors that confirm the predetermined belief that the client is lying. The juror will then ignore all indicators that the client is telling the truth and will selectively remember the behaviors that "prove" he/she is lying.
So if nonverbal behaviors are a bad way to detect lying, what can people do to determine how truthful someone else is? Here are a few things to look for:
1. A lack of spontaneity in the person's recollection of events: If the person cannot readily remember details of a major life event without prompting, it may indicate that the person is trying to make up the story as he/she goes along.
2. Ambivalence in story telling: Comments such as, "I think that it happened that way, but maybe not, I can't exactly remember, yeah, I guess that's what happened," are strongly indicative of deception.
3. Lack of credibility: People who are un-credible are probably liars (for example, someone who is known to have lied in the past is probably going to lie again. Also, a 4 year-old child is probably an un-credible reporter of the truth).
4. Implausible statements: If the person is saying things that could not have possibly happened, he/she is almost definitely lying.
The good news is that when jurors are instructed by the judge or attorneys about how to properly detect deception, they tend to do a much better job of telling truth from fiction.
Field, T., Malphurs, J. E., Yando, R., Bendell, D., Carraway, K., & Cohen, R. (2010). Legal Interviewers Use Children’s Affect and Eye Contact Cues to Assess Credibility of Their Testimony. Early Child Development and Care, 180(3), 397-404.
Hartwig, M. &; Bond, C. F. (2011). Why Do Lie-Catchers Fail? A Lens Model Meta-Analysis of Human Lie Judgments. Psychological Bulletin, 137(4), 643-659.
Levine, T. R., Asada, J. K., & Park, H. S. (2006). The Lying Chicken and the Gaze Avoidant Egg: Eye Contact, Deception, and Causal Order. Southern Communication Journal, 71(4), 401-411.
Sitton, S. C. & Griffin, S. T. (1981). Detection of Deception From Clients’ Eye Contact Patterns. Journal of Counseling Psychology, 28(3), 269-271.
Sporer, S. L. & Schwandt, B. (2007). Moderators of Nonverbal Indicators of Deception: A Meta-Analytic Synthesis. Psychology, Public Policy, and Law (13)1, 1-34.