Detecting Deception *

David A. Gershaw, Ph.D.

This title is likely to get your attention, because we all would like to know if and when we are being deceived. When most of us think of deception, we picture criminals lying about their innocence. However, people conceal the truth for other reasons. A profession may demand hiding your true feelings. (Have you ever dealt with customer complaints?) We may need to hide our true feelings to avoid antagonizing co-workers or supervisors. ("Sure, boss, I don't mind working overtime.") We may deceive out of consideration for others, like acting happy at the dinner table even though you may feel depressed. Even though we may want to hide our true feelings at times, how can we detect deception in others?

The best indicators of deception are nonverbal cues those that are above and beyond the words a person uses to communicate. Nonverbal cues may involve kinesics what most people call "body language" proxemics face-to-face distance cues paralanguage speech rate, response time, pitch and tone of voice or other cues.

There are two main types of nonverbal cues for deception. Deception cues are cues that indicate an attempt to conceal something, but they do not indicate what is being concealed. These include body tension, smiles that last too long, taking an unusual amount of time before answering a question. They merely give you a "feeling" that the person is not completely truthful.

In contrast, leakage cues can betray the underlying emotion that the person is trying to conceal. They could be a faint smile on a person feigning sadness or pencil tapping while someone is trying to indicate attentiveness.

The distinction between these two is important. Both cues depend on the deceiver's skill at deceiving and the perceiver's skill at detecting. However, many people are good at detecting some types of cues but not others. Possibly different skills are needed for each type of cue, but it is more likely that leakage cues are more subtle and difficult to spot than deception cues.

What are some deception cues? Most people are aware of facial expressions. However, even if perceivers are more skilled in detecting facial cues, deceivers are more skilled in hiding them. Some of the more likely nonverbal cues are indicated below:

Kinesics can involve less eye contact, more or less smiling than usual, excessive gestures, more body tension and/or more body shifting or fidgeting.

Paralanguage can include longer time before responding, speech less fluent and/or higher tone of voice.

Overall, there can be inconsistent or contradictory messages from various cues.

However, it is very important to remember that these cues only indicate anxiety; they do not necessarily reflect deception. Without any attempt at deception, the anxiety of any interview may promote these cues.

Can we be trained to detect these cues better? A psychological experiment was done to compare the ability of trained customs inspectors to those of untrained subjects. Airline passengers were asked to participate in a mock inspection procedure. Some were given "contraband" to conceal. The real customs inspectors and the untrained subjects were asked to detect the "smugglers" from videotapes. Contrary to expectations, both groups failed to pick out many of the smugglers. In addition, both groups showed high agreement as to who should be searched and who should not.

Even trained observers do not do
much better than chance in detecting deception.

The above results go along with many other psychological studies. Observers seem to be good at detecting cues they believe to indicate deception whether the cues really do or not. In addition, they are quite confident that they have accurately identified honest or deceptive behavior. Unfortunately, their average accuracy is 55% only 5% better than chance. (You can get 50% accuracy merely by flipping a coin to make your decision.)

In the long run, being truthful but tactful is much better than deception. Deception may succeed for a while. However, once it is detected, it is hard if not impossible to build up the bond of trust that existed beforehand. We have to ask ourselves, "Is it worth the risk?"

* Adapted from Steven Penrod's Social Psychology, Prentice-Hall, 1983, pages 270-273.

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