A Longitudinal Study of the Development of Emotional Deception Detection Within New Same-Sex Friendships.

Previous studies show that close friends improve at lie detection over time. However, is this improvement due to an increase in the ability to decode the feelings of close friends or a change in how close friends communicate their true and deceptive emotions? In a study of 45 pairs of friends, one friend from each pair (the "sender") was videotaped showing truthful and faked affect in response to pleasant and unpleasant movie clips. The other friend from each pair (the "judge") guessed the true emotions of both the friend and a stranger 1 month and 6 months into the friendship. Judges were better at guessing the true emotions of friends than strangers, and this advantage in judging friends increased among close friends over time. Surprisingly, improvement over time was due mostly to a change in the sender's communication, rather than an increase in judges' ability to decode their friends' feelings.

Individual differences in judging deception: accuracy and bias.

The authors report a meta-analysis of individual differences in detecting deception, confining attention to occasions when people judge strangers' veracity in real-time with no special aids. The authors have developed a statistical technique to correct nominal individual differences for differences introduced by random measurement error. Although researchers have suggested that people differ in the ability to detect lies, psychometric analyses of 247 samples reveal that these ability differences are minute. In terms of the percentage of lies detected, measurement-corrected standard deviations in judge ability are less than 1%. In accuracy, judges range no more widely than would be expected by chance, and the best judges are no more accurate than a stochastic mechanism would produce. When judging deception, people differ less in ability than in the inclination to regard others' statements as truthful. People also differ from one another as lie- and truth-tellers. They vary in the detectability of their lies. Moreover, some people are more credible than others whether lying or truth-telling. Results reveal that the outcome of a deception judgment depends more on the liar's credibility than any other individual difference.

Accuracy of deception judgments.

We analyze the accuracy of deception judgments, synthesizing research results from 206 documents and 24,483 judges. In relevant studies, people attempt to discriminate lies from truths in real time with no special aids or training. In these circumstances, people achieve an average of 54% correct lie-truth judgments, correctly classifying 47% of lies as deceptive and 61% of truths as nondeceptive. Relative to cross-judge differences in accuracy, mean lie-truth discrimination abilities are nontrivial, with a mean accuracy d of roughly .40. This produces an effect that is at roughly the 60th percentile in size, relative to others that have been meta-analyzed by social psychologists. Alternative indexes of lie-truth discrimination accuracy correlate highly with percentage correct, and rates of lie detection vary little from study to study. Our meta-analyses reveal that people are more accurate in judging audible than visible lies, that people appear deceptive when motivated to be believed, and that individuals regard their interaction partners as honest. We propose that people judge others' deceptions more harshly than their own and that this double standard in evaluating deceit can explain much of the accumulated literature.

Cues to deception.

Do people behave differently when they are lying compared with when they are telling the truth? The combined results of 1,338 estimates of 158 cues to deception are reported. Results show that in some ways, liars are less forthcoming than truth tellers, and they tell less compelling tales. They also make a more negative impression and are more tense. Their stories include fewer ordinary imperfections and unusual contents. However, many behaviors showed no discernible links, or only weak links, to deceit. Cues to deception were more pronounced when people were motivated to succeed, especially when the motivations were identity relevant rather than monetary or material. Cues to deception were also stronger when lies were about transgressions.

Nonverbal behavior and self-presentation.

Because of special characteristics of nonverbal behaviors (e.g., they can be difficult to suppress, they are more accessible to the people who observe them than to the people who produce them), the intention to produce a particular nonverbal expression for self-presentational purposes cannot always be successfully translated into the actual production of that expression. The literatures on people's skills at using their nonverbal behaviors to feign internal states and to deceive are reviewed as they pertain to the question of whether people can overcome the many constraints on the translation of their intentions into expressions. The issue of whether people's deliberate attempts to regulate their nonverbal behaviors can be detected by others is also considered.