Social identity and perceptions of media persuasion: Are we always less influenced than others?

People typically perceive negative media content (e.g., violence) to have more impact on others than on themselves (a third-person effect). To examine the perceived effects of positive content (e.g., public-service advertisements) and the moderating role of social identities, we examined students' perceptions of the impact of AIDS advertisements on self, students (in- group), nonstudents (out-group), and people in general. Perceived self-other differences varied with the salience of student identity. Low identifiers displayed the typical third-person effect, whereas high identifiers were more willing to acknowledge impact on themselves and the student in-group. Further, when influence was normatively accept able within the in-group, high identifiers perceived self and students (us) as more influenced than nonstudents (them). The theoretical and practical implications of this reversal in third-person perceptions are discussed.

Subgroup relations: A comparison of mutual intergroup differentiation and common ingroup identity models of prejudice reduction

Two studies examined relations between groups (humanities and math-science students) that implicitly or explicitly share a common superordinate category (university student). In Experiment 1, 178 participants performed a noninteractive decision-making task during which category salience was manipulated in a 2 (superordinate category salience) x 2 (subordinate category salience) between-groups design. Consistent with the mutual intergroup differentiation model, participants for whom both categories were salient exhibited the lowest levels of bias, whereas bias was strongest when the superordinate category alone was made salient. This pattern of results was replicated in Experiment 2 (N = 135). In addition, Experiment 2 demonstrated that members of subgroups that are nested within a superordinate category are more sensitive to how the superordinate category is represented than are members of subgroups that extend beyond the boundaries of the superordinate category.

Attachment style as a predictor of sexual attitudes and behavior in late adolescence

This research applied attachment theory to the study of sexual attitudes and behaviors in a sample of late adolescents. Four hundred and seventy heterosexual undergraduate students completed questionnaires assessing attachment (discomfort with closeness; anxiety over relationships), relationship history, communication about sex, sexual self-efficacy and locus of control, and attitudes to condoms. Eight weeks later, participants reported on sexual behaviors occurring during the eight-week interval, and perceived risk of these activities. Both discomfort with closeness and anxiety over relationships were associated with external locus of control for sexual outcomes, and with use of drugs before sexual contact. Anxiety over relationships was linked to unsafe sex and to negative attitudes to condoms, but discomfort with closeness was associated with a more cautious approach to sexual risk-taking. Some results were qualified by gender differences, and by differences between the full sample and those who were sexually active. The findings are discussed in terms of attachment style and its links with communication and affect regulation.

Design of the multicenter Australian study of epidural anesthesia and analgesia in major surgery: The MASTER Trial

The Multicenter Australian Study of Epidural Anesthesia and Analgesia in Major Surgery (The MASTER Trial) was designed to evaluate the possible benefit of epidural block in improving outcome in high-risk patients. The trial began in 1995 and is scheduled to reach the planned sample size of 900 during 2001. This paper describes the trial design and presents data comparing 455 patients randomized in 21 institutions in Australia, Hong Kong, and Malaysia, with 237 patients from the same hospitals who were eligible but not randomized. Nine categories of high-risk patients were defined as entry criteria for the trial. Protocols for ethical review, informed consent, randomization, clinical anesthesia and analgesia, and perioperative management were determined following extensive consultation with anesthesiologists throughout Australia. Clinical and research information was collected in participating hospitals by research staff who may not have been blind to allocation. Decisions about the presence or absence of endpoints were made primarily by a computer algorithm, supplemented by blinded clinical experts. Without unblinding the trial, comparison of eligibility criteria and incidence of endpoints between randomized and nonrandomized patients showed only small differences. We conclude that there is no strong evidence of important demographic or clinical differences between randomized and nonrandomized patients eligible for the MASTER Trial. Thus, the trial results are likely to be broadly generalizable. Control Clin Trials 2000;21:244-256 (C) Elsevier Science Inc. 2000.

Size-based predation by kookaburras (Dacelo novaeguineae) on lizards (Eulamprus tympanum : Scincidae): what determines prey vulnerability?

Lizards and birds are both popular model organisms in behavioural ecology, but the interactions between them have attracted little study. Given the putative importance of birds as predators of diurnal Lizards, it is of considerable interest to know which traits (of lizards as well as birds) influence the outcome of a predatory attempt. We studied predation by giant terrestrial kingfishers (kookaburras, Dacelo novaeguineae: Alcedinidae) on heliothermic diurnal lizards (highland water skinks, Eulamprus tympanum: Scincidae), with particular reference to the role of prey (lizard) size. Our approach was twofold: to gather direct evidence (sizes of lizards consumed in the field, compared to those available) and indirect evidence rite-related shifts in lizard behaviour). We quantified the size structure of a natural population of skinks (determined by an extensive mark-recapture program), and compared it to the sizes of wild lizards taken by kookaburras (determined by analysis of prey remains left at the birds' nests,. Kookaburras showed size-based predation: they preyed mainly on small and medium-sized rather than large lizards in the field. However, the mechanism producing this bias remains elusive. It is not due to any distinctive behavioural attributes (locomotor ability, activity level, habitat usage) of the lizards of the size class disproportionately taken by the kookaburras. The greater vulnerability of subadult lizards may reflect subtle ontogenetic shifts in ecological and behavioural traits, but our data suggest that great caution is needed in inferring patterns of vulnerability to predation from indirect measures based on either the prey or the predator alone. Instead, we need direct observations on the interaction between the two.

The evolution and star formation of dwarf galaxies in the Fornax Cluster

We present the results of a spectroscopic survey of 675 bright (16.5 < b(J) < 18) galaxies in a 6 degrees field centred on the Fornax cluster with the FLAIR-II spectrograph on the UK Schmidt Telescope. Three galaxy samples were observed: compact galaxies to search for new blue compact dwarfs, candidate M 32-like compact dwarf ellipticals, and a subset of the brightest known cluster members in order to study the cluster dynamics. We measured redshifts for 516 galaxies, of which 108 were members of the Fornax Cluster. Defining dwarf galaxies to be those with b(J) greater than or equal to 15 (M-B greater than or equal to - 16.5), there are a total of 62 dwarf cluster galaxies in our sample. Nine of these are new cluster members previously misidentified as background galaxies. The cluster dynamics show that the dwarf galaxies are still falling into the cluster whereas the giants are virialized. We classified the observed galaxies as late-type if we detected H alpha emission at an equivalent width greater than 1 Angstrom. The spectra were obtained through fixed apertures, so they reflect activity in the galaxy cores, but this does not significantly bias the classifications of the compact dwarfs in our sample. The new classifications reveal a higher rate of star formation among the dwarf galaxies than suggested by morphological classification: 35 per cent have significant H alpha emission indicative of star formations but only 19 per cent were morphologically classified as late-types. The star-forming dwarf galaxies span the full range of physical sizes and we find no evidence in our data for a distinct class of star-forming blue compact dwarf (BCD) galaxy. The distribution of scale sizes is consistent with evolutionary processes which transform late-type dwarfs to early-type dwarfs. The fraction of dwarfs with active star formation drops rapidly towards the cluster centre: this is the usual density-morphology relation confirmed here for dwarf galaxies. The star-forming dwarfs are concentrated in the outer regions of the cluster, the most extreme in an infalling subcluster. We estimate gas depletion time-scales for five dwarfs with detected Hi emission: these are long (of order 10(10) yr), indicating that an active gas removal process must be involved if they are transformed into gas-poor dwarfs as they fall further into the cluster. Finally, in agreement with our previous results, we find no compact dwarf elliptical (M 32-like) galaxies in the Fornax Cluster.

Why do non-color words interfere with color naming?

In the non-color-word Stroop task, university students' response latencies were longer for low-frequency than for higher frequency target words. Visual identity primes facilitated color naming in groups reading the prime silently or processing it semantically (Experiment 1) but did not when participants generated a rhyme of the prime (Experiment 3). With auditory identity primes, generating an associate or a rhyme of the prime produced interference (Experiments 2 and 3). Color-naming latencies were longer for nonwords than for words (Experiment 4). There was a small long-term repetition benefit in color naming for low-frequency words that had been presented in the lexical decision task (Experiment 5). Facilitation of word recognition speeds color naming except when phonological activation of the base word increases response competition.

Mortality and recurrent cardiac events after coronary artery bypass graft: long term outcomes in a population study

Objective: To determine 30 day mortality, long term survival, and recurrent cardiac events after coronary artery bypass graft (CABG) in a population. Design: Follow up study of patients prospectively entered on to a cardiothoracic surgical database. Record linkages were used to obtain data on readmissions and deaths. Patients: 8910 patients undergoing isolated first CABG between 1980 and 1993 in Western Australia. Main outcome measures: 30 day and long term survival, readmission for cardiac event (acute myocardial infarction, unstable angina, percutaneous transluminal coronary angioplasty or reoperative CABG). Results: There were 3072 deaths to mid 1999. 30 day and long term survival were significantly better in patients treated in the first five years than during the following decade. The age of the patients, proportion of female patients, and number of grafts increased over time. An urgent procedure (odds ratio 3.3), older age (9% per year) and female sex (odds ratio 1.5) were associated with increased risk for 30 day mortality, while age (7% per year) and a recent myocardial infarction (odds ratio 1.16) influenced long term survival. Internal mammary artery grafts were followed by better short and long term survival, though there was an obvious selection bias in favour of younger male patients. Conclusions: This study shows worsening crude mortality at 30 days after CABG from the mid 1980s, associated with the inclusion of higher risk patients. Older age, an acute myocardial infarction in the year before surgery, and the use of sephenous vein grafts only were associated with poorer long term survival and greater risk of a recurrent cardiac event. Female sex predicted recurrent events but not long term survival.

Can I have your attention please: Repressors and enhanced P3 to emotional stimuli

In four experiments ERPs to emotional (negative and positive) and neutral stimuli were examined as a function of participants’ trait anxiety and repressivedefensiveness. The experiments investigated the time course of attentional bias in the processing of such stimuli. Pictures of angry, happy, and neutral faces were used in two of the experiments and pictures ofmutilated, happy, and neutral faces were used in the others. ERP’s to emotional and neutral stimuli were recorded from parietal, temporal, and frontal sites. Analysis of the P3 component indicated that the peak magnitude of the P3 at the parietal and temporal sites reflected an interactive function of trait anxiety and defensiveness. Repressors (low reported anxiety, high defensiveness) showed a consistent pattern of greater P3 magnitude at the parietal and temporal sites for emotional faces (angry, happy, and mutilated) than did high-anxious and low-anxious participants. Participants did not differ in P3 magnitude when ERPs to neutral stimuli were investigated (e.g., a fixation cross). The findings indicate that Repressors dedicate greater processing resources to emotional material, as compared to neutral material, than either the high-anxious or low-anxious individuals. Results of the four experiments are discussed within the theoretical framework of Derakshan and Eysenck (1998). The importance of understanding the role of differences in information processing, in the experience and avoidance of emotional information, as a function of trait anxiety and defensiveness is emphasized.

'You can criticise because you care': Identification, constructiveness, and the intergroup sensitivity effect

Group criticisms judged to be reasonable in the mouth of an ingroup member are aggressively rejected when they stem from an outgroup member (the intergroup sensitivity effect). Mediational analyses suggest that this phenomenon is underpinned by an attributional bias; criticisms from insiders are more likely to be perceived as being motivated for constructive reasons than are criticisms from outsiders, thus arousing lower levels of defensiveness. But what if group members were to receive information that called into question the ingroup critic's commitment to the group? For example, if the ingroup critic was known to be a low identifier with their group, or used language to suggest that they were psychologically distancing themselves from their group, we might expect that ingroup critics will be downgraded as strongly as outgroup critics. Furthermore, it might be possible for people to turn an outgroup criticism into an ingroup criticism by making salient their shared identity at the superordinate level. Three experiments are described that provide support for each of these propositions.

Using partially structured attitude measures to enhance the attitude-behavior relationship

This article recalls a classic scheme for categorizing attitude measures. One particular group of measures, those that rely on respondents' interpretations of partially structured stimuli, has virtually disappeared from attitude research. An attitude measure based on respondents' interpretation of partially structured stimuli is considered. Four studies employing such a measure demonstrate that it predicts unique variance in self-reported and actual behavior, beyond that predicted by explicit and contemporary implicit measures and regardless of whether the attitude object under consideration is wrought with social desirability concerns. Implications for conceptualizing attitude measurement and attitude-behavior relations are discussed.

Attenuation of perceptual asymmetries in patients with early-onset schizophrenia: Evidence in favour of reduced hemispheric differentiation in schizophrenia?

Lateral biases in visual perception have been demonstrated in normal individuals and in patients with unilateral brain lesions. It has been suggested that the absence of structural and functional asymmetries in schizophrenia could be due to a failure in lateralisation that may be most pronounced in those patients whose illness onset is at an early age. Here we examined lateral biases in patients with schizophrenia of an early onset (N = 21) and a late onset.(N = 19), and their respective age-matched control groups, using the greyscales task, a sensitive measure of asymmetries in visual processing. The stimuli consisted of two rectangles, one above the other, shaded in opposite directions and matched overall for darkness. Participants judged which of the two rectangles looked darker overall. Previous studies using this task in healthy participants have reported a reliable bias, such that the rectangle with the darker end on the left is selected preferentially. Whereas the late-onset patients in this study exhibited a perceptual bias of similar direction and magnitude to that of controls, this was not the case for the early-onset patients, who exhibited significantly less bias than their control group. The reduced perceptual bias seen in the early-onset group, but not the late-onset group, suggests an attenuation of right hemisphere mechanisms dedicated to processing vistiospatial information. The attenuated perceptual asymmetry in the early-onset group only may be consistent with the view that (i) an earlier illness onset reflects a greater loss of hemispheric differentiation and (ii) reduced functional asymmetries in the early-onset group are a manifestation of a failure to allocate functions to one or the other hemisphere.

Comparing predictions of extinction risk using models and subjective judgement

Models of population dynamics are commonly used to predict risks in ecology, particularly risks of population decline. There is often considerable uncertainty associated with these predictions. However, alternatives to predictions based on population models have not been assessed. We used simulation models of hypothetical species to generate the kinds of data that might typically be available to ecologists and then invited other researchers to predict risks of population declines using these data. The accuracy of the predictions was assessed by comparison with the forecasts of the original model. The researchers used either population models or subjective judgement to make their predictions. Predictions made using models were only slightly more accurate than subjective judgements of risk. However, predictions using models tended to be unbiased, while subjective judgements were biased towards over-estimation. Psychology literature suggests that the bias of subjective judgements is likely to vary somewhat unpredictably among people, depending on their stake in the outcome. This will make subjective predictions more uncertain and less transparent than those based on models. (C) 2004 Elsevier SAS. All rights reserved.

Sonification supports eyes-free respiratory monitoring and task time-sharing

Three experiments explored the effectiveness of continuous auditory displays, or sonifications, for conveying information about a simulated anesthetized patient's respiration. Experiment 1 established an effective respiratory sonification. Experiment 2 showed an effect of expertise in the use of respiratory sonification and revealed that some apparent differences in sonification effectiveness could be accounted for by response bias. Experiment 3 showed that sonification helps anesthesiologists to maintain high levels of awareness of the simulated patient's state while performing other tasks more effectively than when relying upon visual monitoring of the simulated patient state. Overall, sonification of patient physiology beyond traditional pulse oximetry appears to be a viable and useful adjunct to visual monitors. Actual and potential applications of this research include monitoring in a wide variety of busy critical care contexts.