A control question test oriented towards students

Control Question Tests were altered for 12 of 24 students who were examined with a polygraph about a mock crime which half of them had committed. The altered tests substituted control questions about students' cheating and plagiarism for the standard questions about crime issues. Responses to the altered tests were compared with those from tests using regular control questions which are usually about criminal issues. All tests were conducted by a professor. Detection scores derived from response magnitudes of skin resistance differed between innocent (M = 2.0) and guilty participants (M = -1.9). Guilt and innocence interacted with the type of test. Those examined with control questions oriented towards students scored as more innocent when actually innocent (M = 4.3) than guilty students examined with the student form (M = -3.0) or the crime form (M = -0.8) of the test and innocent students (M = -0.3) examined with control questions oriented towards crimes. The discussion is augmented by results from a direct analysis of magnitude of scores.     

Awareness of crime-relevant information and the Guilty Knowledge Test.

The effects of awareness of crime-relevant information on the detection of deception with the Guilty Knowledge Test were examined. Student Ss were assigned to 1 of 3 groups: a guilty group, members of which committed a mock crime; an innocent group aware of details about the crime; or an innocent group unaware of such information. After following instructions, Ss were tested on the polygraph with a 10-item Guilty Knowledge Test and were offered $20 for an innocent test outcome. Skin resistance response scores of guilty Ss lying about crime-relevant information were higher than the scores of innocent informed Ss, whose scores in turn were higher than those of innocent unaware Ss. This replicated findings of an earlier study in which similar procedures were used and supported the view that Ss aware of crime-relevant information can appear less deceptive than Ss lying about crime-relevant information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysiological detection through the guilty knowledge technique: Effect of mental countermeasures.

The effects of mental countermeasures on the efficiency of psychophysiological detection with the Guilty Knowledge Technique were examined in a mock-crime experiment with 4 groups of participants: innocent participants who were not involved in the mock crime, guilty controls who committed the mock crime but received no countermeasure instructions, guilty participants who received countermeasure instructions, and guilty participants who received countermeasure instructions and were allowed to practice the countermeasures. The countermeasure instructions encouraged participants to recall emotional situations from their past and imagine themselves in these situations during presentation of irrelevant questions. Results revealed a significant reduction in electrodermal detection efficiency under the 2 countermeasure conditions with no differences between them. No countermeasure effects were observed with the respiration line length measure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Leakage of relevant information to innocent examinees in the GKT: An attempt to reduce false-positive outcomes by introducing target stimuli.

This study focused on the Guilty Knowledge Test (GKT)—a psychophysiological detection method based on a series of multiple-choice questions, each having one relevant and several neutral (control) alternatives. The study examined a new method designed to reduce false-positive outcomes due to leakage of relevant items to innocent suspects by introducing target items (i.e., items known to all examinees but unrelated to the crime) to which participants have to respond (e.g., by pressing a key) while answering the GKT questions. Informed innocent participants showed relatively larger electrodermal responses to the critical items than uninformed participants, but not as large as the responses made by guilty participants. No differences between informed and uninformed innocent participants were obtained with a respiration measure. The use of the target items tended to reduce the differences between informed and uninformed innocent participants. The results further demonstrated that electrodermal responding to the relevant items was correlated with memory of these items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deception and nondeception in guilty knowledge and guilty actions polygraph tests.

Two polygraph tests, the Guilty Knowledge Test (GKT) and the Guilty Actions Test (GAT), were compared in a laboratory setting. Men (N?=?120) who committed or witnessed a mock crime were required to answer "no"", to repeat items, or to remain silent in response to items on the GKT or the GAT. A monetary reward was promised for appearing innocent on the test. An interaction with scores based on skin resistance responses showed that innocent witnesses tested on the GKT and guilty participants tested with either the GKT or the GAT scored more in the guilt direction than did innocent witnesses tested on the GAT. Furthermore, participants who were required to say "no"" were more reactive to key items than were participants in the silent group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity of an expanded-issue (Modified General Question) polygraph technique in a simulated distributed-crime-roles context.

The validity of an expanded-issue control-question technique that is commonly used in investigations was tested with simulations of thief, accomplice, confidant, and innocent crime roles. Field numerical scores and objective measures discriminated between the guilty and innocent groups. Excluding inconclusives (guilty?=?18.1%, innocent?=?20.8%), decisions based on total numerical scores were 84.7% correct for the guilty group and 94.7% correct for the innocent group. There was relatively weaker, but significant, discrimination between the thief group and the other guilty groups and no significant discrimination between the accomplice group and confidant group. Skin conductance, respiration, heart rate, and cardiograph measures contributed most strongly to discrimination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The GSR in the detection of guilt.

How accurate is a lie detector in determining guilt? "Forty-nine male college students, after random assortment into four groups, were required to enact one, both, or neither of two mock crimes. All were then given a guilty knowledge test, employing the GSR, which used six standard questions relating to each of the two crimes. A simple, objective, and a priori scoring system was used to determine guilt. Forty-four or 89.8% of the Ss were assigned to their correct group, against a chance expectancy of 25%. Considering the crimes separately, all Ss innocent of a crime were correctly classified, while 44 or 50 interrogations of guilty Ss gave guilty classifications, a total of 93.9% correct classification against a chance expectancy of 50%… . Detection of guilty knowledge… is demonstrably capable of very high validity in those situations where it can be used." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of feedback of physiological information on responses to innocent associations and guilty knowledge.

Investigated the effects of providing Ss with feedback concerning their physiological responding while they were questioned about (a) innocent associations varying in degree of personal involvement and (b) innocent associations vs guilty knowledge. In Exp I, 48 undergraduates were divided into 3 groups—electrodermal, heart-rate, or no feedback. Ss were then questioned separately about a list of geometric figures, containing one that they had chosen beforehand, and about a list of Social Security numbers, which included their own. Results, based on the relative amplitude of electrodermal responses, indicate that feedback significantly augmented responses to the relevant item as did personal involvement. In Exp II, 26 undergraduates were provided with guilty knowledge about a mock crime while another 26 Ss received innocent associations. Half of each group received electrodermal feedback and half no feedback. Results show significant differences in the responding of guilty and innocent Ss. Feedback increased responding to relevant items in both groups. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of antianxiety drugs as countermeasures in the detection of guilty knowledge.

To evaluate whether antianxiety drugs enable guilty Ss to appear innocent on polygraph tests, the authors compared the effects of diazepam, meprobamate, and propranolol on the outcome of a guilty knowledge test (GKT). 75 undergraduate students were evenly divided among 1 innocent and 4 guilty groups. Ss in each of the guilty groups received either 1 of the drugs or a placebo prior to the administration of the GKT and after viewing a videotape that depicted a burglary as seen from the perspective of the burglar. The results showed that drug status had no influence on the outcome of the GKT. Innocent Ss who coincidentally obtained high scores on a recognition memory test covering details of the mock crime tended to obtain higher guilt scores on the GKT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social psychology and plea bargaining: Applications, methodology, and theory.

Conducted 2 experiments with male undergraduates to investigate the plea bargaining process. Exp I (143 Ss) used a role-playing procedure to identify variables that affect the acceptance of a plea bargain. 18% of the Ss playing the role of innocent defendants accepted the plea bargain, whereas 83% of the guilty defendants accepted. Two other main effects revealed that defendants were more likely to accept a plea bargain when relatively many charges had been filed against them and/or when the severity of punishment upon conviction was great, although internal analyses revealed that these effects were present in guilty defendants only. Exp II (18 Ss) was conducted using involved participants to provide validation for the major result of Exp I. Ss were made to be innocent or guilty of having prior information about an exam. All were accused of having used prior information and were given an opportuinity to plea bargain rather than face an ethics committee. In accord with Exp I, guilty Ss accepted the plea bargain significantly more often than innocent students. Results are discussed in terms of information differences between innocent and guilty defendants and the availability heuristic. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the decision to testify in one's own behalf: Effects of withheld evidence, defendant's sexual preferences, and juror dogmatism on juridic decisions.

360 undergraduates high or low in dogmatism served as members of 6-person juries that assessed the culpability of a homosexual or heterosexual defendant in a murder trial. Defendants either (a) invoked the 5th Amendment in response to specific crime-relevant interrogation, (b) invoked the 5th Amendment by opting not to take the witness stand, or (c) took the stand and provided substantive answers for all crime-relevant interrogation. Results indicate that defendants who invoked the 5th Amendment (either on the stand or by declining to take the stand) were judged more likely to be guilty and more deserving of conviction than their counterparts who took the stand and answered all questions. As anticipated, juror dogmatism interacted with the defendant's sexual preferences to affect juridic decisions. However, the form of these interactions were contrary to expectations: High dogmatic jurors were no more punitive toward homosexual than heterosexual defendants, whereas jurors low in dogmatism were actually more lenient toward homosexual than heterosexual defendants. An explanation for the leniency of nondogmatic jurors toward homosexual defendants is proposed, and some implications of this line of reasoning for future research are discussed. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of Polygraph Data Obtained From Individuals Involved in Mock Crimes and Actual Criminal Investigations.

In a preliminary attempt to determine the generalizability of data from laboratory mock-crime studies, the authors examined the similarities and differences among the cardiovascular, electrodermal, and respiration responses of deceptive and nondeceptive individuals elicited to crime-relevant and crime-irrelevant questions. Participants in the laboratory group were randomly assigned to nondeceptive (n = 28) or deceptive (n = 27) treatment groups, and a mock-crime scenario was used. The field participants were confirmed nondeceptive (n = 28) or deceptive (n = 39) criminal suspects who underwent polygraph examinations between 1993 and 1997. The results indicated that there were salient differences between field and similarly obtained laboratory polygraph response measures. However, accuracy of laboratory participants' classifications using logistic regression analysis was not significantly different from field participants' classification accuracy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do the clothes make the man? An exploration of the effect of lineup attire on eyewitness identification accuracy.

In 3 experiments, 392 undergraduates witnessed staged crimes and attempted to identify criminals from photographic lineups containing a picture of the guilty party or a similar looking but innocent suspect. Lineup attire was manipulated: (1) Only the suspects wore clothing similar to that worn during the crime (biased lineups); (2) everyone wore different attire (usual lineups); and (3) everyone was dressed alike. Data reveal that the rate of identifications of the guilty party was not influenced by lineup attire. However, the innocent suspect was most likely to be identified from a clothing-biased lineup. Data also show that Ss who selected the suspect clothing from photographs of clothing were significantly more accurate in their identification of the person than Ss who failed to select the suspect clothing. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Robustness of the sequential lineup advantage.

A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup advantages and 3 significant simultaneous advantages. Both sequential advantages occurred when the good photograph of the guilty suspect or either innocent suspect was in the fifth position in the sequential lineup; all 3 simultaneous advantages occurred when the poorer quality photograph of the guilty suspect or either innocent suspect was in the second position. Adjusting the statistical criterion to control for the multiple tests (.05/24) revealed no significant sequential advantages. Moreover, despite finding more conservative overall choosing for the sequential lineup, no support was found for the proposal that a sequential advantage was due to that conservative criterion shift. Unless lineups with particular characteristics predominate in the real world, there appears to be no strong preference for conducting lineups in either a sequential or a simultaneous manner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of physical countermeasures on the physiological detection of deception.

In Exp I, 48 undergraduates were divided into 4 groups, 3 of which enacted a mock crime. Two of these guilty groups were trained in the use of a countermeasure, either biting the tongue (pain countermeasure) or pressing the toes against the floor (muscle countermeasure) during the control question zones of the control question test (CQT). All countermeasure Ss were given extensive information about the nature of the CQT. Results show that no significant effects for countermeasures were found. In Exp II, 57 Ss were divided into 3 groups, 2 of which enacted a mock crime, to assess the effects of additional training and concurrent use of both countermeasures. Results show that countermeasure Ss produced 47% false negative outcomes as compared to no false negatives for guilty control Ss. False negative outcomes occurred when Ss were able to produce physiological responses that were larger to control questions than to relevant questions. Findings should be qualified by the possibility that the countermeasure task would be more difficult if the relevant questions dealt with a real crime in an actual investigation. It is concluded that a substantial number of Ss can be trained to defeat a CQT in a laboratory paradigm. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Seeing Black: Race, Crime, and Visual Processing.

Using police officers and undergraduates as participants, the authors investigated the influence of stereotypic associations on visual processing in 5 studies. Study 1 demonstrates that Black faces influence participants' ability to spontaneously detect degraded images of crime-relevant objects. Conversely, Studies 2-4 demonstrate that activating abstract concepts (i.e., crime and basketball) induces attentional biases toward Black male faces. Moreover, these processing biases may be related to the degree to which a social group member is physically representative of the social group (Studies 4-5). These studies, taken together, suggest that some associations between social groups and concepts are bidirectional and operate as visual tuning devices--producing shifts in perception and attention of a sort likely to influence decision making and behavior. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Detection of guilty knowledge in real-life criminal investigations.

The present study provides a first attempt to estimate the validity of the Guilty Knowledge Test (GKT) in real-life criminal investigations. Skin resistance responses in GKT records of 50 innocent and 48 guilty Ss, for whom actual truth was established by confession, were analyzed by two methods. On the basis of an a priori decision rule, 98% of the innocent and 42% of the guilty Ss were correctly classified. Signal detection measures based on various possible decision rules indicated that the distribution of guilty Ss was highly differentiated from the distribution of innocent Ss. An optimal decision rule yielded correct classifications for 94% of the innocent Ss and 65% of the guilty Ss. These results suggest that the GKT could be a useful investigative tool that protects innocent suspects from being falsely classified as guilty. The false-negative identifications were accounted for in terms of the realistic conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Human versus computerized evaluations of polygraph data in a laboratory setting.

Computer algorithms that process physiological reactions to polygraph test questions and assess the probability that the questions were answered truthfully were evaluated with data obtained in two mock crime experiments. One half of the subjects in each experiment were guilty of committing a mock theft, and one half were innocent. Data from 100 subjects in one experiment (standardization sample) were used to develop a discriminant function of electrodermal, cardiovascular, and respiration measures. The distributions of discriminant scores were used to derive Bayesian assessments of the probability of truthfulness. Data from 48 subjects in another experiment were used to cross validate the computer model (validation sample). Dichotomous computer classifications of subjects in the standardization sample were 93% correct. Blind numerical evaluations of the same data by an expert interpreter were 89% correct. On cross-validation, computer outcomes were 94% correct, and numerical evaluations were 92% correct. There were no significant differences between computer and human evaluations. The findings suggest that computer techniques may be developed for applied settings and would perform at least as well as expert human interpreters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)