Mechanisms underlying response bias in deception detection

Abstract

The present research aims to explore the mechanisms underlying response bias in detection of deception. In addition to examining the predictive value of generalized communicative suspicion (GCS), age, and professional experience, the present approach also investigates the role of error weighting by testing the hypothesis that a greater concern about Misses is associated with a lie bias. In Study 1, we analyzed samples of (a) students, (b) police trainees, and (c) police officers. Results revealed an asymmetrical error weighting as the strongest predictor of response bias. Supporting our hypothesis, participants who were more concerned about False Alarms were particularly truth biased, whereas a lie bias was observed among those who were more concerned about Misses. In Study 2, we manipulated the error weighting in order to test its causal relation to response bias. Results again show the predictive value of asymmetrical error weighting for response bias in deception detection, and indicate that the effects of the manipulation are moderated by individuals' habitual error weighting.     

The application of multiple lineups in a field study

Abstract

The usefulness of multiple lineups was tested in a field experiment with nine different targets. Six hundred and forty-eight passers-by were asked for directions in the pedestrian zone of a university town. Subsequently, they were approached by a different person and asked to identify the target from portrait, body, and profile lineups. Additionally, participants were asked to identify a shopping bag that the target had carried. Two of the lineups were target-present, and two target-absent. Diagnosticity ratios (DRs) were computed for target/suspect choices, lineup rejections and foil choices. Compared to foil choices and rejections, target/suspect choices were most diagnostic of guilt. Here, the combination of lineups was superior over individual lineups. Lineup rejections showed some capability of establishing innocence, but with lower DRs than target/suspect choices. Here, combinations did not increase diagnosticity. The diagnosticity of multiple foil choices was acceptable for portrait face lineups but limited for all other lineups or combinations.     

True and false intentions: asking about the past to detect lies about the future

This study is on how to discriminate between true and false intentions, an emerging area within psycholegal research. We argue that asking about the past (the planning phase) might be a promising way to detect lies about the future (intentions). That is, participants who had developed false intentions to mask their criminal intentions were assumed to provide equally long and detailed answers to questions about intentions, compared to participants who told the truth about their intentions. In contrast, we predicted that lying participants would be worse at answering questions about the planning of their stated (false) intentions, compared to participants telling the truth about the planning of their stated (true) intentions. To test our assumptions, we used a newly devised experimental set-up accommodating the main characteristics of intent. Both lying and truth-telling suspects perceived the questions on planning as more unanticipated, and more difficult to answer, compared to the questions about their intentions (future actions). Furthermore, in support of our predictions we found that the truth-telling (vs. lying) suspects' answers to questions on planning were longer and perceived as more detailed and clear, whereas liars' and truth-tellers' answers to questions on intentions were equally long and perceived as equally detailed.     

The acid phosphatase test two minute cut-off: An insufficient time to detect some semen stains

The ability to detect semen in sexual offence cases is a crucial first step to locating stains which may be suitable for DNA profiling. Since the development of the acid phosphatase test in the late1950s by Stuart S. Kind, the process undertaken to perform the test has gone largely unchanged. The method currently accepted by operational forensic science laboratories allows 2 min for a reaction to be obtained, and until relatively recently, this has not been challenged. In this research, samples of semen were obtained from three donors and a range of dilutions for each sample were prepared. Each dilution was subjected to acid phosphatase testing using both direct testing and the ‘press test’ method. The results showed that semen could be detected in excess of 15 min in dilutions up to 1 in 400 using the press test method and in dilutions up to 1 in 1000 using the direct method. Of further significance was the observation that using the press test method, the two minute cut-off was insufficient to detect the majority of stains and in some cases, semen stains as strong as 1 in 20 dilutions. This research provides compelling evidence for protocols currently utilised in forensic practice to be reviewed in order that forensic scientists do not overlook potential evidential material that may prove suitable for body fluid identification such as DNA STR profiling.     

Theoretical and legal issues related to choice blindness for voices

Purpose. To examine whether choice blindness occurs for auditory stimuli, namely voices. Methods. One hundred participants listened to three pairs of voices and had to decide each time which one they found more sympathetic or sounded more criminal. After they made a choice, participants were presented with the chosen voice again and had to match it to a face. However, during the second trial, participants were actually presented with the voice they had previously not chosen. Results. Only 19% of the participants detected this change concurrently, an additional 10% detected it retrospectively. This indicates that choice blindness transfers to auditory stimuli. Whether participants had previously evaluated sympathy or criminality of the voices had no effect on choice blindness. Conclusions. The study shows that choice blindness is a robust phenomenon that can also be elicited when auditory stimuli are employed. Implications for earwitness testimony and expert witnesses in the context of forensic speech analysis are discussed.     

A Matter of Genius

Jacqueline Rose, States of Fantasy, Oxford: Oxford University Press, 1996, £25,1998 (pbk.), £12.99.

Wulf Sachs, Black Hamlet, with a new introduction by Saul Dubow and Jacqueline Rose, Baltimore and London: The Johns Hopkins University Press, 1996, £14 pbk.     

‘Me and My Drank:’ Exploring the Relationship Between Musical Preferences and Purple Drank Experimentation

“Purple drank” is a label typically applied to mixtures of codeine cough syrup with soda, although it has also been applied to mixtures of over-the-counter cough syrups and alcohol. This novel drug formulation was first popularized in the Houston, Texas rap music scene in the 1990’s, and since then references to purple drank have become common in rap and hip-hop songs, but remained virtually absent in other musical genres. Prior research has found that musical preferences can have an influence on choice and frequency of drug use. The goal of the present study is to examine the relationship between musical preferences and experimentation with purple drank. Self-reported information about musical preferences, substance use, and demographic characteristics were collected from 2,349 students at a large university in the southeastern United States. An analysis of lifetime purple drank and other drug use by musical preferences reveals that those who prefer rap/hip-hop music and rock/alternative have the highest risk for reporting purple drank use. Further, this relationship far exceeds the associations between musical preferences and other drugs. Results from logistic regression analyses indicate males, other drug users, and those that prefer rap/hip-hop music have a significantly higher likelihood of using purple drank.     

The Boomerang Effect: A Case Study of the Murray‐Darling Basin Plan

In the period from 1997 to 2009 Australia experienced a severe drought, which significantly affected the Murray‐Darling Basin. The drought has broken but state governments are still in conflict over water allocations. The establishment of the Murray‐Darling Basin Authority (MDBA) in 2007 was intended to address these issues but the management of the Basin remains complicated by constitutional ambiguity. This paper addresses the question of whether it is possible to implement effective policies for the health of the Murray‐Darling Basin without the present danger of a drought. We suggest that the MDBA has encountered what Beck refers to as the ‘boomerang effect’. The MDBA's plans seem to have produced new challenges and the Authority might find the Basin is exposed to risks it has created.