Deception, Linguistic Cues to

Much of human social interaction involves trying to uncover what other people think and feel. At the same time, it is often advantageous for people to try to conceal their thoughts and feelings. This discrepancy has given rise to a substantial body of research on the most effective ways to detect deception. Most experts agree that there is no consistent “tell” that gives away a liar. Instead, the most useful cues to deception are those that reveal something about the liar's underlying cognitive and emotional state. This entry provides a brief overview of linguistic cues to a deceptive state of mind.

Language contains a variety of cues that may indicate that a person is attempting to be deceptive. Because telling a lie requires the construction and retelling of a false story, true and false stories are thought to be qualitatively different from one another. In general, linguistic approaches to deception tend to focus not on the content of deceptive stories but rather on the way that these stories are told.

The primary purpose of language is to communicate our inner monologue to the outside world. Thus, choosing one pronoun over another may reveal very different ways of thinking about people—we implies a closer relationship than you and I. And in some contexts, using an inappropriate verb tense may reveal attempts to conceal part of the story. In 1994, Susan Smith drowned her children in a lake, fabricating a kidnapping story to cover her crime. According to FBI expert Susan Adams, before Smith was a suspect in the children's deaths, she told reporters, “My children wanted me. They needed me. And now I can't help them.” Normally, relatives will speak of a missing person in the present tense. The fact that Smith used the past tense in this context suggested to trained FBI agents that she already viewed them as dead.

Depending on the circumstances, cues to deception may be evident in the structure of a story, the words used to tell it, and the physical characteristics of a person's speech. In general, the language used to tell deceptive stories has four key features. First, deceptive stories tend to be shorter and more repetitive, presumably as a strategy to avoid contradicting one's own story. Second, deceptive stories are less complex than true stories. The process of creating a false story consumes cognitive resources, leading liars to tell simpler stories. Third, deceptive stories are less immediate than true stories. Immediate language is direct, clear, relevant, and personal, and is often defined in terms of a general impression by the receiver of the communication. Fourth, deceptive stories tend to contain more negative emotion. Liars may feel guilty, either about lying or about the topic they are discussing. Diary studies of small everyday lies suggest that people feel discomfort and guilt while lying and immediately afterward.

Several studies have focused specifically on usage of different types of words. One useful way to study the words that people use is to count and categorize words using a computer program called Linguistic Inquiry and Word Count (LIWC), developed by James Pennebaker and Martha Francis. LIWC analyzes text (or transcribed speech) on a word-byword basis. The result of this analysis is a profile of the kinds of words people use. A recent paper by Matt Newman and colleagues used this computer [Page 211]program to compare the use of language in true and false stories. Using this approach, Newman and colleagues were able to correctly classify liars and truth tellers at a rate of 61% overall.

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