Confidence Can Be Used to Discriminate Between Accurate and Inaccurate Lie Decisions.

There is a long-standing belief that confidence is not useful at discriminating between accurate and inaccurate deception decisions. Historically, this position made sense because people showed little ability to discriminate lie-tellers from truth-tellers. But, it is now widely accepted that, under certain conditions, people can discriminate between lie-tellers and truth-tellers. Nevertheless, belief that confidence does not discriminate between accurate and inaccurate responses persists. This belief is somewhat paradoxical because, to the extent that people can discriminate between lie-tellers and truth-tellers, signal detection theory naturally predicts a positive relationship between confidence and accuracy. In line with our signal-detection-based predictions, we show that, among decisions about whether someone is lying, those made with high confidence are more accurate than those made with low confidence. This important relationship has gone unnoticed in past work because of a reliance on inappropriate measures. Past research examining the confidence-accuracy relationship in deception research relied on correlating average confidence with proportion of correctly identified lies. These correlations provide information on whether more confident judges tend to be more accurate but remain silent on the arguably more important question of whether higher confidence decisions are more accurate than lower confidence decisions. We show that confidence-accuracy characteristic analyses are uniquely suited to measuring the confidence-accuracy relationship in deception research.

You must be lying because I don't understand you: Language proficiency and lie detection.

We examined the impact of interviewees' language proficiencies on observers' lie detection performance. Observers (N = 132) were randomly assigned to make deception judgments about interviewees (N = 56) from Four proficiency groups (i.e., native, advanced, intermediate, and beginner English speakers). Discrimination between lie- and truth-tellers was poorest when observers judged beginner English speakers compared to interviewees from any other proficiency group. Observers were also less likely to exhibit a truth-bias toward nonnative than native English speakers. These results suggest that interviewing individuals in their nonnative languages can create inequalities in the justice system. (PsycINFO Database Record

Less is more? Detecting lies in veiled witnesses.

Judges in the United States, the United Kingdom, and Canada have ruled that witnesses may not wear the niqab-a type of face veil-when testifying, in part because they believed that it was necessary to see a person's face to detect deception (Muhammad v. Enterprise Rent-A-Car, 2006; R. v. N. S., 2010; The Queen v. D(R), 2013). In two studies, we used conventional research methods and safeguards to empirically examine the assumption that niqabs interfere with lie detection. Female witnesses were randomly assigned to lie or tell the truth while remaining unveiled or while wearing a hijab (i.e., a head veil) or a niqab (i.e., a face veil). In Study 1, laypersons in Canada (N = 232) were more accurate at detecting deception in witnesses who wore niqabs or hijabs than in those who did not wear veils. Concealing portions of witnesses' faces led laypersons to change their decision-making strategies without eliciting negative biases. Lie detection results were partially replicated in Study 2, with laypersons in Canada, the United Kingdom, and the Netherlands (N = 291): observers' performance was better when witnesses wore either niqabs or hijabs than when witnesses did not wear veils. These findings suggest that, contrary to judicial opinion, niqabs do not interfere with-and may, in fact, improve-the ability to detect deception. (PsycINFO Database Record

Psychopathy and deception detection.

Researchers have found that most people have difficulty detecting deception; however, certain individuals are able to consistently detect deception above the level of chance. This study examined whether psychopathic traits are related to deception detection. Undergraduate participants (n = 117) indicated whether individuals in video clips were lying or telling the truth and completed a measure of psychopathy. Overall, participants' performance was significantly greater than chance. Scores on the psychopathy measure were unrelated to participants' performance and their confidence on the lie detection task. Possible explanations for the findings are briefly discussed.

The reliability of lie detection performance.

We examined whether individuals' ability to detect deception remained stable over time. In two sessions, held one week apart, university students viewed video clips of individuals and attempted to differentiate between the lie-tellers and truth-tellers. Overall, participants had difficulty detecting all types of deception. When viewing children answering yes-no questions about a transgression (Experiments 1 and 5), participants' performance was highly reliable. However, rating adults who provided truthful or fabricated accounts did not produce a significant alternate forms correlation (Experiment 2). This lack of reliability was not due to the types of deceivers (i.e., children versus adults) or interviews (i.e., closed-ended questions versus extended accounts) (Experiment 3). Finally, the type of deceptive scenario (naturalistic vs. experimentally-manipulated) could not account for differences in reliability (Experiment 4). Theoretical and legal implications are discussed.

Police interviewing and interrogation: a self-report survey of police practices and beliefs.

By questionnaire, 631 police investigators reported on their interrogation beliefs and practices-the first such survey ever conducted. Overall, participants estimated that they were 77% accurate at truth and lie detection, that 81% of suspects waive Miranda rights, that the mean length of interrogation is 1.6 hours, and that they elicit self-incriminating statements from 68% of suspects, 4.78% from innocents. Overall, 81% felt that interrogations should be recorded. As for self-reported usage of various interrogation tactics, the most common were to physically isolate suspects, identify contradictions in suspects' accounts, establish rapport, confront suspects with evidence of their guilt, and appeal to self-interests. Results were discussed for their consistency with prior research, policy implications, and methodological shortcomings.

"Intuitive" lie detection of children's deception by law enforcement officials and university students.

Adults' ability to detect children's deception was examined. Police officers, customs officers, and university students attempted to differentiate between children who lied or told the truth about a transgression. When children were simply questioned about the event (Experiment 1), the adult groups could not distinguish between lie-tellers and truth-tellers. However, participants were more accurate when the children had participated in moral reasoning tasks (Experiment 2) or promised to tell the truth (Experiment 3) before being interviewed. Additional exposure to the children did not affect accuracy (Experiment 4). Customs officers were more certain about their judgments than other groups, but no more accurate. Overall, adults have a limited ability to identify children's deception, regardless of their experience with lie detection.