The Deception Quiz
Test your knowledge about deception.
Posted Jan 06, 2020
Many people find the topic of human deception fascinating. What I like most about deception research is that in the realm of deception, nothing is what it seems. To see what I mean, try taking this short quiz.
1. How good are people at distinguishing truths from lies?
2. How can you tell if a person is lying?
3. In general, are you better at detecting the lies of strangers or lies told by someone you know well? That is, does knowing a person hinder or facilitate accurate lie detection?
4. True or false: Most people lie less frequently than the average person?
Research shows that most laypeople overestimate their ability to detect deception. Researchers, in contrast, both underestimate and overestimate people’s ability to detect deception. It is not uncommon to read that deception detection is no better than chance. This is not what the research shows.
People are significantly better than chance with a moderate effect size (d = .4). But, this does not mean that people are good (or bad) lie detectors. At least, as it is tested in deception detection experiments, the average accuracy is 54 percent.
Things, however, are less straightforward than this very robust research finding suggests. The catch is, the research designs in deception detection experiments share methodological features that shape results in important ways. As strange as it sounds, research results are both too pessimistic and too optimistic.
The big reason most deception detection experiments underestimate people’s ability is that they usually preclude the lie detection strategies that are most effective. As an example, when I am trying to tell if someone is lying to me, I ask myself if the person has a reason to lie. I know that absent a reason to lie, people are almost invariably honest. This would not help me if the person I was talking to was randomly assigned to lie or tell the truth as part of an experiment.
Similarly, in everyday life, I can sometimes fact-check. Research participants never have this option. Basically, I would not have access to my lie detection toolbox in a typical lie detection experiment. Even if I am a good lie detector, I couldn’t demonstrate that.
Lie detection research, however, has another methodological feature that impacts results in the opposite direction. People are explicitly asked to consider honesty. If my idea of the truth-default is right, experimental designs get people thinking about a question that otherwise might not even come to mind.
People in deception detection research are put on guard for lies in a way that people outside the lab are most often not. The upshot is, when it comes to recognizing a lie as a lie, people are usually much less adept at lie spotting than the research suggests. The vast majority of lies go undetected, at least initially.
When people are asked the second question, by far, the top answer is gaze aversion. People everywhere believe that liars won’t look you in the eye. At least two things are remarkable about this finding. First, it is pan-cultural. The belief is held around the world. Second, it is false. There is no association between eye behavior and actual honesty. The diagnostic value of the gaze is zero.
Decades of research show that reliance on real-time sender nonverbal and linguistic behavior makes people poor (but not chance-level) lie detectors. Fortunately, there are several ways to improve lie detection. I hinted at two above. I’ll post more about how to better detect lies in my next post.
Most people think that people are better at detecting deception by friends, family, and romantic partners than strangers. This makes good sense. The research on the question, however, provides evidence for both sides.
Deception detection experiments involving friends and strangers tend to yield systematically higher levels of accuracy than experiments involving strangers. At the same time, being close increases both over-confidence in one’s own lie detection ability and the tendency to believe (truth-bias). Relational closeness blinds us to the possibility of deception. Consequently, while more knowledge of another person can aid lie detection, it also facilitates systematically falling for lies told by those close to us.
The last question asked is if most people lie less often than the average person. This is true. For example, in a nationally representative survey of U.S. adults, 75 percent were below average. The average was 1.6 lies per day. The modal response of zero was provided by 60 percent of the sample.
Another 15 percent provided the second frequent answer, which was just one lie. The reason most people were below average is that the distribution of lie prevalence is highly skewed. On any given day, most people do not lie very much, and most lies are told by few prolific liars. The few prolific liars pattern has now been replicated several times in several countries.
Bond, C. F., & The Global Deception Research Team (2006). A world of lies. Journal of Cross-Cultural Psychology, 37, 60-74.
DePaulo, B. M., Lindsay, J. J., Malone, B. E., Muhlenbruck, L., Charlton, K., & Cooper, H. (2003). Cues to deception. Psychological Bulletin, 129, 74-118.
Levine, T. R. (2015). New and improved accuracy findings in deception detection research. Current Opinion in Psychology, 6, 1-5.
McCornack, S. A., & Parks, M. R. (1986). Deception detection and relationship development: The other side of trust. In M.L. McLaughlin (Ed.) Communication Yearbook 9. Beverly Hills, CA: Sage.