Feature Centrality and Conceptual Coherence

Conceptual features differ in how mentally tranformable they are. A robin that does not eat is harder to imagine than a robin that does not chirp. We argue that features are immutable to the extent that they are central in a network of dependency relations. The immutability of a feature reflects how much the internal structure of a concept depends on that feature; i.e., how much the feature contributes to the concept's coherence. Complementarily, mutability reflects the aspects in which a concept is flexible. We show that features can be reliably ordered according to their mutability using tasks that require people to conceive of objects missing a feature, and that mutability (conceptual centrality) can be distinguished from category centrality and from diagnosticity and salience. We test a model of mutability based on asymmetric, unlabeled, pairwise dependency relations. With no free parameters, the model provides reasonable fits to data. Qualitative tests of the model show that mutability judgments are unaffected by the type of dependency relation and that dependency structure influences judgments of variability.     

Trait anxiety, defensiveness and selective processing of threat: an investigation using two measures of attentional bias

Attentional biases for threat were examined in a non-clinical sample (N=60), with each participant tested on both the modified Stroop colour-naming and dot probe tasks. Three groups were selected on the basis of trait anxiety and social desirability scale (SDS) scores: “low anxiety” (LA: low trait, low SDS), “repressor” (REP: low trait, high SDS) and “high anxiety” (HA: high trait, low SDS). Results from the colour-naming task suggested that high levels of defensiveness (in combination with low trait anxiety) were associated with greater avoidance of threat. The REP group showed less interference in colour-naming threat than neutral words; whereas the HA group showed increased interference due to threat words. On the dot probe task, there was a general tendency for this non-clinical sample as a whole to show avoidance of social threat relative to neutral words, but there was no bias for physical threat words. Avoidance of social threat was significant only within the REP group. No relationships were found between the measures of cognitive bias from the two tasks, suggesting different underlying mechanisms. Results are discussed in relation to previous findings and theoretical views of the effects of anxiety and defensiveness on the processing of threat.     

Are absolute frequencies,relative frequencies,or both effective in reducing cognitive biases?

Biases in probabilistic reasoning are affected by alterations in the presentation of judgment tasks. In our experiments, students made likelihood judgments that an event was produced by various causes. These judgments were made in terms of probability, relative frequency or absolute frequency on a full or a pruned list of causes. When they had little personal experience of the event (causes of death), the pruning bias was smaller with relative frequencies than with absolute frequencies or probabilities. When they had more personal experience of the event (missing a lecture), the bias was less with both types of frequency than with probability but still lowest with relative frequency. We suggest that likelihood information is usually stored as relative frequencies when it has been obtained from public sources but that it is based on event counts when it is derived from personal experience. Copyright © 2000 John Wiley & Sons, Ltd.     

Understanding of the current police caution (England and Wales)

The Criminal Justice and Public Order Act 1994 (England and Wales) modified suspects' right to silence during police questioning and required a new police caution. The current 37-word caution was introduced after it was found that a proposed 60-word draft version was too complex. The results of the present study show that, although more succinct, the current caution is no easier to explain. Even under optimal conditions, when the participants could focus on each sentence in turn, only 1 in 10 of the general population (n=15), 6 in 10 of A-level students preparing for university (n=72) and 9 in 10 police officers (n=21) demonstrated their understanding by explaining all three sentences correctly. For all groups, the difficulties were more marked when the caution was presented in its entirety, as would happen in real life. The complexity of the caution has serious implications for suspects in police detention. © 1998 John Wiley & Sons, Ltd.     

Thirdhand smoke beliefs and behaviors among healthcare professionals

Thirdhand smoke (THS) refers to tobacco smoke contaminants and by-products that remain in the environment after a cigarette is extinguished. The purpose of this study was to assess beliefs and behaviors regarding THS among healthcare professionals, and to examine associations among smoking attitudes/beliefs, provider demographics, and THS beliefs and behaviors. Healthcare professionals (N = 204) at a comprehensive cancer center and affiliated general hospital in a northeastern urban area completed online questionnaires. About one third of the respondents had heard of THS before completing the survey, and more than two thirds of the sample believed that THS issues do not receive enough attention. Being female, likelihood of discussing THS with others, endorsing the belief that smoking affects the quality of parenting, and support for government action towards smoking bans were significantly associated with providers’ belief that THS is harmful. Endorsing the belief that smoking affects the quality of parenting and belief that THS is harmful were significantly associated with the likelihood of discussing THS with others. Findings shed light on THS beliefs and behaviors of healthcare providers (a group of individuals that could be trained to educate and advise patients about THS) and inform recommendations for new tobacco policies and clinical guidelines for best practices in tobacco control and prevention.     

How Prevalent is Contract Cheating and to What Extent are Students Repeat Offenders?

Contract cheating, or plagiarism via paid ghostwriting, is a significant academic ethical issue, especially as reliable methods for its prevention and detection in students’ assignments remain elusive. Contract cheating in academic assessment has been the subject of much recent debate and concern. Although some scandals have attracted substantial media attention, little is known about the likely prevalence of contract cheating by students for their university assignments. Although rates of contract cheating tend to be low, criminological theories suggest that people who employ ghostwriters for their assignments are likely to re-offend, and little is known about re-offence rates in this form of academic misconduct. We combined previously-collected datasets (N = 1378) and conducted additional, and previously-unreported, analyses on self-report measures of contract cheating prevalence. We found that few students (3.5%), on aggregate, ever engaged in contract cheating but this varied substantially among samples (from 0.3% to 7.9%). Of those who ever engaged in contract cheating, 62.5% did so more than once. The data also suggested that engagement in contract cheating is influenced by opportunity. These figures may help policy makers, and researchers who are creating contract cheating detection methods, to estimate base rates of contract cheating and the likelihood of re-offence.