Police officers ability to detect deception in high stakes situations and in repeated lie detection tests

Thirty‐seven police officers, not identified in previous research as belonging to groups that are superior in lie detection, attempted to detect truths and lies told by suspects during their videotaped police interviews. In order to measure consistency in their ability, the officers each participated in four different tests, each of which was on a different day. They were asked to indicate their confidence in being able to distinguish between truths and lies prior to the first test and after completing all four tests. We predicted that accuracy rates would be higher than those typically found in research with police officers; that good or poor performances on an individual test would be partly caused by luck, and, consequently, participants' accuracy scores were likely to progress towards the mean if their performance on all four tests was to be combined; and that officers would underestimate their own performance. These hypotheses were supported. Copyright © 2006 John Wiley & Sons, Ltd.     

Detecting lies in young children,adolescents and adults

The ability of teachers, social workers, police officers and laypersons (undergraduate and postgraduate students) to detect truths and lies told by 5–6 year‐olds, adolescents and adults was tested in the present experiment. Lie detectors judged the veracity of statements from 18 liars and 18 truth tellers belonging to these three age groups. Accuracy scores were around 60% for each of these three age groups, both for detecting truths and for detecting lies. No occupational differences emerged. Moreover, judgements made by teachers, social workers and police officers showed an overlap, suggesting that an erroneous decision made by a member of one group may not easily be detected by a member of the other groups. The lie detectors were inclined to judge cues of nervousness, cognitive demand and attempted behavioural control as cues to deceit, even when truth tellers were displaying these cues. Copyright © 2006 John Wiley & Sons, Ltd.     

Prospective factors contribute little to within-session changes in responding

Five rats pressed levers for food delivered by a multiple variable interval 1-min variable interval 1-min schedule. In theunpredictable conditions, sessions were 20, 40, 60, 80, or 100 min long, determined randomly at the beginning of each session. In thepredictable conditions, each of these session durations was presented for 15 consecutive sessions. Rate of responding changed systematically within the session even when the end of the session was unpredictable. This implies that prospective factors related to anticipation of the end of the session are not necessary for producing withinsession changes in responding. Within-session patterns of responding were also similar for the predictable and unpredictable conditions. This suggests that prospective factors contributed little to the form of the within-session patterns under the present conditions.     

Using the Reverse Order Technique with Non‐Native Speakers or Through an Interpreter

We examined whether the reverse order technique can be implemented when people speak through an interpreter. A total of 40 Chinese, 40 Korean and 30 Hispanic participants were interviewed in English or in their own native language through an interpreter. Interviewees were asked to tell the truth or lie about a secret meeting they viewed. They were asked to recall what they saw in chronological order and then in reverse order. The reverse order technique revealed two cues to deceit (detail and commissions) when an interpreter was present, whereas no cues to deceit emerged when interviewees spoke in English. This suggests that the reverse order technique can be used with an interpreter but possibly not with non‐native speakers. Perhaps the combined task of speaking in a non‐native language and reporting in reverse order is mentally taxing for liars and truth tellers, thus making differences between them unlikely to emerge. Copyright © 2015 John Wiley & Sons, Ltd.     

Processing emotional category congruency between emotional facial expressions and emotional words

Facial expressions are critical for effective social communication, and as such may be processed by the visual system even when it might be advantageous to ignore them. Previous research has shown that categorising emotional words was impaired when faces of a conflicting valence were simultaneously presented. In the present study, we examined whether emotional word categorisation would also be impaired when faces of the same (negative) valence but different emotional category (either angry, sad or fearful) were simultaneously presented. Behavioural results provided evidence for involuntary processing of basic emotional facial expression category, with slower word categorisation when the face and word categories were incongruent (e.g., angry word and sad face) than congruent (e.g., angry word and angry face). Event-related potentials (ERPs) time-locked to the presentation of the word-face pairs also revealed that emotional category congruency effects were evident from approximately 170 ms after stimulus onset.     

Facilitating memory‐based lie detection in immediate and delayed interviewing: The role of mnemonics

We experimentally investigated how different mnemonic techniques employed in an interview conducted immediately after an event affected truth tellers' and liars' responses when they were interviewed again after a 2‐week delay. We also compared how verbal accounts changed over time within truth tellers and liars, and how consistent both groups were. Participants (n = 143) were shown a mock intelligence operation video and instructed either to tell the truth or lie about its contents in two interviews, one of which was immediately after watching the video and the other after a 2‐week delay. In the immediate interview, they were asked to provide a free recall and then asked to provide further information via one of three mnemonics: context reinstatement, sketch, or event‐line. In the delayed interview, they were asked to provide only a free recall. Truth tellers reported more visual, spatial, temporal, and action details than did liars both immediately and after a delay. Truth tellers experienced more of a decline in reporting details after a delay than did liars, and this decline was affected by the mnemonic used. Truth tellers thus showed, more than liars, patterns of reporting indicative of genuine memory decay. Liars produced patterns of a “stability bias” instead. Truth tellers and liars were equally consistent between their immediate and delayed statements.