Polygraph Examiner Awareness of Crime-Relevant Information and the Guilty Knowledge Test

A mock-theft experiment was designed to examine the efficiency of the Guilty Knowledge Test when (a) the examiner was aware of some of the crime-relevant items; (b) target items (i.e., items that are significant to participants for reasons other than crime-relevance) were incorporated into the test; (c) the motivation of guilty participants to appear innocent was manipulated. Results indicated that (a) participants yielded weaker responses to relevant items when the examiner was aware of them than when he did not have the knowledge; (b) the inclusion of target items had no overall effect on the responses to the relevant items: (c) within the guilty condition, highly motivated participants were more responsive to the relevant items than less motivated participants, and the inclusion of target items significantly decreased detection accuracy of low motivated participants.     

Effectiveness of pupil diameter in a probable‐lie comparison question test for deception

Purpose. There were three objectives of this study: (1) To assess the possibility of using pupil diameter as an index of deception in the context of a comparison question polygraph test. (2) To determine if pupil diameter would make a significant contribution to an optimal multivariate classification equation in combination with the traditional predictor variables used in field polygraph practice. (3) We explored the possibility of replacing one or more of the traditional predictor variables with pupil diameter. Methods. We used a laboratory mock crime experiment with 24 participants, half of whom stole $20 (US) from a secretary's purse. Participants were tested with a comparison question test modelled after standard field practice. Physiological measures were taken with laboratory quality instrumentation. Features were extracted from the physiological measures. Those features were subjected to a number of different statistical analyses. Results. Innocent participants showed larger increases in pupil diameter in response to probable‐lie questions than to relevant questions. Guilty participants did not show differential responding to the question types. The additional of pupil diameter to a multivariate classification model approached, but did not reach significance. Subsequent analyses suggest that pupil diameter might be used to replace the traditional relative blood pressure measure. Conclusions. Pupil diameter was found to be a significant predictor variable for deception. Pupil diameter may be a possible replacement for the traditional relative blood pressure measure. Additional research to explore that possibility would seem to be warranted.     

The Effect of Gender in the Perception of Elder Physical Abuse in Court

Two experiments investigated mock jurors' perceptions of elder abuse (EA) in a physical assault case. In Experiment 1, participants read a fictional criminal trial summary of a physical assault case in which the alleged victim was 66, 76, or 86 years old. In Experiment 2, the age of the alleged victim was 76 years old, but the gender of the alleged victim and the gender of the defendant were crossed. The results of the experiments showed that women believed the alleged victim more and rendered a guilty verdict more often than men. Overall, the alleged victim was believed more than the defendant regardless of the age of the alleged victim, and most verdicts were guilty. These results are discussed in terms of the factors that affect perceptions of alleged victims of EA in court.     

Guilty and innocent suspects’ strategies during police interrogations

Abstract

Deception detection has largely failed to investigate guilty and innocent suspects’ strategies. In this study, mock suspects (n=82) were interrogated by police trainees (n=82) who either were or were not trained in the technique to strategically use the evidence (the SUE technique). Analyses revealed that guilty suspects to a higher degree than innocent suspects applied strategies in order to appear truthful. Guilty suspects reported diverse strategies, while innocent suspects reported the strategy to tell the truth like it had happened, indicating a belief in the visibility of innocence. The realism in the suspects’ expectation about how their veracity was judged was largely dependent on the way in which they had been interrogated. The truth-telling suspects who were interrogated according to the SUE technique were optimistic about being judged as truthful; this optimism was warranted as the vast majority of them were classified as truthful. The SUE technique seems to help (a) spotting guilty suspects without them being aware of it and (b) spotting innocent suspects, and they become aware of it. That innocent (but not guilty) suspects can read how the interrogator views them is advantageous for the investigative process.     

Interviewing to Elicit Cues to Deception: Improving Strategic Use of Evidence with General-To-Specific Framing of Evidence

Previous research has demonstrated that the strategic use of evidence (SUE) approach of interviewing criminal suspects is effective at eliciting cues to deception. This study aims at expanding on the SUE approach by testing the technique of general-to-specific evidence framing. We conducted an experiment using a mock terrorism paradigm. Guilty participants took part in a simulated act of terrorism, while innocent participants performed a similar act involving no transgression. All participants (N?=?102) were then interviewed using one of four evidence disclosure styles (early disclosure, late disclosure, 2-step disclosure, or 4-step disclosure). We expected that disclosing evidence to the suspect gradually, with increasing specificity, would induce guilty suspects to alter their statements to a greater extent than innocent suspects. General-to-specific evidence framing effectively discriminated between guilty and innocent suspects, but results only partially supported the hypotheses.     

The occurrence of eye blinks during a guilty knowledge test

Abstract

In the present experiment we examined whether eye blinks could discriminate between guilty and innocent examinees in a Guilty Knowledge Test (GKT). Based on the assumption that guilty examinees would experience more cognitive load when responding to the key items than to the control items, we hypothesized that they would display fewer eye blinks during the key items than during the control items. For innocent examinees, responding to the key and control items should be equally demanding, and no differences in eye blinks between key and control items were expected. A total of 26 participants took part in an experiment where 13 guilty examinees committed a mock theft (of an exam paper) and the remaining 13 innocent examinees went on with their normal business. All participants underwent a GKT whereby their eye blinks were measured. Both guilty and innocent examinees displayed the pattern of eye blinks that we predicted. The implications of the findings are discussed.     

Stigma and wrongful conviction: all exonerees are not perceived equal

Exonerees report experiencing stigma post-incarceration. This research examined whether particular exonerees are stigmatized more than others. Participants read an article about a fictional exoneree who falsely confessed, was misidentified by an eyewitness, or was implicated by a jailhouse snitch, and then reported their perceptions. Participants in the control condition did not read an article. An exoneree who falsely confessed was more likely to be perceived as actually guilty of the crime, less competent, and less warm than the other exonerees, but participants did not express more anger or less pity toward any particular exoneree. Participants did express more pity when rating exonerees than in the control condition, but this did not translate into a greater willingness to offer the exonerees more governmental assistance (e.g., job training, psychological counseling). Exonerees who falsely confess were stigmatized more than other exonerees. The implications for the post-incarceration experiences of exonerees who falsely confess are discussed.     

The Mr. Big technique on trial by jury

Mr. Big is a Canadian undercover police technique used to elicit confessions. Undercover officers befriend the suspect, and gradually draw them into a fictitious criminal organization. Upon meeting the boss of the organization, ‘Mr. Big’, the suspect is pressured to confess. When evidence from the sting operation, including the confession, is presented later in court, it may induce juror moral prejudice towards a defendant. We evaluated how situational and dispositional sting factors (crime task severity, financial incentive, and defendant intelligence) influence mock juror moral prejudice and decision-making in Mr. Big cases. Results from Experiment 1 (N?=?270) showed fewer guilty verdicts in the high incentive conditions. In Experiment 2 (N?=?1,666), high incentive and low defendant intelligence were related to fewer guilty verdicts, more favorable ratings of defendant character, and more skeptical evaluations of confession evidence. Additionally, there were differences between community and student participants on multiple outcomes.     

Social Pressure Mediates the Negative Impact of Guilt on Fair Allocation in Multi-Party Interactions

Previous research documents the negative effect of guilt on allocation behaviors in three-party dictator games. In these studies, guilty dictators gave more resources to their victims but fewer to third parties. We test whether this allocation behavior reflects greater social pressure from the victim in comparison to a third party (Experiment 1), and whether this pressure is reduced if a guilty dictator must take away resources as opposed to giving resources to the two players (Experiment 2). In two experiments, participants distributed 200 tokens in a three-party dictator game after an experimental manipulation of guilt in which participants learned they caused or did not cause their partner to lose a potential reward. In Experiment 1, dictators randomly assigned to the guilty condition reported more social pressure from the victims. Social pressure differences mediated the relationship between the experimental manipulation of guilt and the distribution of tokens between the dictator’s previous partner and another player. In Experiment 2, guilty dictators randomly assigned to take resources from the other two players reported more social pressure from the new player, and distributed the tokens more fairly between their previous partner and the new player in comparison to guilty dictators required to give resources to the other two players. Participants’ allocation behavior reflects social pressure from victims (created by feelings of guilt) and third parties (which depends upon whether game outcomes for other players are framed as rewards or costs).

     

Information does not affect the validity of a comparison question test

Purpose . Detailed information about the comparison question test (CQT) and possible countermeasures are now available on the Internet. This study examined whether the provision of such information would affect the validity of the Test for Espionage and Sabotage, a directed lie variant of the CQT. Method . Forty participants were divided into four equal groups: guilty, guilty informed, innocent, and innocent informed. During a first appointment, participants either did or did not commit a mock crime: then some were provided with a book containing detailed information on the CQT, including possible countermeasures. After 1 week with the book, all participants were administered a CQT during their second appointment. Following the polygraph, participants responded to a questionnaire that asked them about their behaviour and perceptions during their examination. Results . There were no significant effects of providing information on the validity of the CQT. However, the reported use of countermeasures was associated with a lower probability of truthfulness. Results of the debriefing questionnaire were found to support predictions made by the theory of the CQT. Conclusions . Concerns that readily available information will enable guilty individuals to produce false‐negative errors seem unfounded. Moreover, the results actually indicate that the use of countermeasures was associated with a lower probability of truthfulness, which was exactly the opposite outcome predicted by the CQT critics.     

On Mimicry and the Psychology of the Belief in a Just World: Imitating the Behaviors of Others Reduces the Blaming of Innocent Victims

Innocent victims of crime are often blamed for what happened to them. In this article, we examine the hypothesis that victim blaming can be significantly reduced when people mimic the behavior of the victim or even a person unrelated to the crime. Participants watched a person on a video after which we assessed the extent of their spontaneous mimicry reactions (Study 1) or participants were instructed to mimic or not to mimic the movements of this person (Study 2). Then, they were informed about a rape and criminal assault and judged the degree to which they thought the victims were responsible for the crime. One of the crimes happened to the same person as the person they previously did or did not mimic. The other crime happened to a person unrelated to the mimicry situation. Results of both studies revealed that previously mimicking the victim or an unrelated person reduced the degree to which victims were being blamed.     

The saliency of gestural misinformation in the perception of a violent crime

Recent research has revealed that misinformation from gestures can influence eyewitness memory. However, it is still unclear whether gestural misinformation can emulate the effects of verbal misinformation on the reporting of major details in serious crimes. To investigate the salience of suggestions provided nonverbally, and how these compare to those made verbally, two experiments were conducted. In Experiment 1, participants watched footage of a crime scene and were presented with one of two types of gestures during questioning that suggested different interpretations of the crime. The results confirmed that the gestures influenced responses, with participants altering their interpretation of the crime according to the information gestured to them. Experiment 2 built on this to investigate how comparable gestural influence was to verbal influence. The results revealed that gestural misinformation caused participants to alter their interpretation of the crime and elicited the same effects as verbal misinformation. Across the two experiments, participants were unlikely to identify the misleading gestures or report feeling misled by them. These results reveal new insights into the strength of gestural misinformation and show that, despite their subtle nature in communication, gestures can exert a powerful influence in eyewitness interviews.     

A Third Verdict Option: Exploring the Impact of the Not Proven Verdict on Mock Juror Decision Making

In most adversarial systems, jurors in criminal cases consider the binary verdict alternatives of "Guilty" and "Not guilty." However, in some circumstances and jurisdictions, a third verdict option is available: Not Proven. The Not Proven verdict essentially reflects the view that the defendant is indeed culpable, but that the prosecution has not proven its case beyond a reasonable doubt. Like a Not Guilty verdict, the Not Proven verdict results in an acquittal. The main aim of the two studies reported here was to determine how, and under what circumstances, jurors opt to use the Not Proven verdict across different case types and when the strength of the evidence varies. In both studies, jurors were more likely to choose a Not Proven verdict over a Not Guilty verdict when the alternative was available. When evidence against the defendant was only moderately strong and a Not Proven verdict option was available (Study 2), there was also a significant reduction in the conviction rate. Results also showed that understanding of the Not Proven verdict was poor, highlighting inadequacies in the nature of judicial instructions relating to this verdict.     

Eyewitness susceptibility to co-witness misinformation is influenced by co-witness confidence and own self-confidence

If an eyewitness is exposed to a co-witness statement that incorrectly blames an innocent bystander for a crime, the eyewitness can be influenced by this statement and also blame the innocent bystander for the crime. This effect is known as blame conformity. In two studies, we examined whether or not this effect is influenced by the degree of confidence a co-witness expresses in her incorrect statement (Study 1) and an eyewitness’s own level of self-confidence (Study 2). Participant eyewitnesses first watched a crime video featuring a perpetrator and an innocent bystander, then read a co-witness statement about the crime that either correctly blamed the perpetrator, incorrectly blamed the innocent bystander, or blamed nobody (a control condition). They were then asked who committed the crime. In Study 1, participants who read an incorrect statement were at increased risk of engaging in blame conformity when the co-witness expressed a high level of confidence, compared to a low level of confidence, in the accuracy of her statement. In Study 2, participants who were lowest in self-confidence were at increased risk of engaging in blame conformity. The theoretical underpinnings of these effects are considered.     

Is Age Irrelevant? Perceptions of Young and Old Adult Eyewitnesses

In Experiment 1, we videotaped elderly and younger adults (n = 69) reporting their memories for a crime video. The seniors were significantly less accurate than the younger adults. In Experiment 2, participants viewed the testimony videotapes and rated the elderly as less credible than the younger adults. In Experiment 3, participant-jurors (n = 302) evaluated transcribed testimonies provided by Experiment 1 participants. The ostensible age of the witnesses was manipulated. Thus, some participants read a senior's testimony believing it was provided by a younger adult and vice versa. Participants were apparently not biased by negative stereotypes of seniors' eyewitness capabilities.