Two forms of minority-group test bias as psychometric artifacts with an animal model (Rattus norvegicus)

Controversy abounds over attributing group differences on tests to nature, nurture, or test bias. Limitations of correlational sampling from natural populations necessitate experimental methods to resolve underlying issues. In classical psychometrics test items are selected from a larger item pool through analysis of item responses in a sample of subjects. Rats of six inbred strains (n = 366) were tested in multiple mazes to provide a large item pool. Six populations were created, each with differing proportions of each strain. Items selected through independent item analyses within each population yielded six tests. An independent cross-validation sample (n = 146) provided scores on all six tests. This sample was also tested in another set of maze problems defined as the criterion to be predicted. Strain means and intrastrain predictive validities for the six tests varied with strain representation in the population used for item selection (p less than .001). Conventional item-selection procedures clearly produced two forms of minority test bias.     

Individual differences in reverse Hindsight bias: I never thought something like chernobyl would happen. Did I?

Hindsight bias was studied in the context of the accident in the Chernobyl nuclear power plant, which took place on April 26th 1986. An individual difference factor which relates to the motivation to process information, need for cognition, was expected to moderate the occurrence of hindsight bias. Probability estimates of many casualties due to the use of nuclear power in The Netherlands were obtained from 212 individuals two months before the accident in Chernobyl. These estimates were compared with similar estimates made in hindsight by the same individuals five months after the accident. Loglinear Analyses reveal a systematic hindsight bias. However, the direction of the bias was contrary to expectations. In hindsight, individuals gave lower probabilities than they actually did two months before the Chernobyl accident. These results reveal a reverse hindsight bias. As hypothesized, need for cognition moderates hindsight bias: individuals low and medium in need for cognition express a systematic reverse hindsight bias, while individuals high in need for cognition do not. High need for cognition individuals also show higher literal consistency between the two measurements, which supports a memory explanation of the moderating effect of need for cognition.     

Marx,technocracy, and the corporatist ethos

Communism, in Marx' mind, did not mean simple liberation, but the economics of liberation. The realm of necessity (technē) was to become the primary field for emancipation (praxis), the latter taking form in new institutions, responsive to real socio-economic needs. In this sense, the problem of technocracy and the corporatist ethos in Marx are part of a broader discursive structure, which links the experiences of workers through the industrial revolution with the philosophies ofpraxis as they reach from Hegel through Marković.     

Many stimuli are frightening,but some are more frightening than others: The contributions of preparedness,dangerousness, and unpredictability to making a stimulus fearful

The nonrandom distribution of situational fears has been explained by evolutionary survival relevance of specific fears. Thirty-eight stimuli were taken from the literature on preparedness and were scored on fearfulness, objective dangerousness, and spatiotemporal unpredictability by three separate groups of students. The same items were scored on survival relevance by 15 biologists. Fearfulness of cues significantly correlated not only with survival relevance but also, and even more strongly, with dangerousness and unpredictability. While the fear/survival relevance association virtually disappeared when the unpredictability contribution was partialed out, the fear/unpredictability correlation was only marginally affected when controlling for survival relevance. This suggests that nonrandomness of feared stimuli may result from the spatiotemporal unpredictability that is attributed to these stimuli. The current practice of using snakes and spiders as phobia-relevant, and flowers and mushrooms as neutral, cues was not justified by the ratings of the 15 independent experts.This study was supported in part by a grant from the Dutch Organization for Fundamental Research (ZWO/Psychon, 560-268-001).     

MMPI profiles of adolescents charged with homicide

Study of adolescent violence has been impeded by failure to distinguish among the circumstances in which youth engage in violent behavior. The present study investigated MMPI profiles of 36 adolescent murderers and a control group of 18 adolescents charged with larceny. Homicide cases were subgrouped into those who committed homicide secondary to another crime (e.g., robbery or rape) and those who acted in the context of interpersonal conflict with the victim. While there were no significant differences between homicide and larceny groups, crime and conflict subgroups were significantly different on scales F, Hs, Hy, and Sc.     

Mass media treatment of violence in sports and its effects

There appears to be a strong relationship between mass media portrayals of violence and real-life violence itself. This article reviews the available literature on the effects of media treatment of sports violence; analyzes the theoretical explanations for this treatment; and makes proposals on how the problems of both sports violence and its media coverage may be remedied, with a particular focus on amateur hockey in Canada.     

Relaxation therapy for tension headache in the elderly: a prospective study

We evaluated the effects of an 8-week progressive muscle-relaxation therapy regimen on the headache activity of 10 elderly tension-headache subjects. Posttreatment assessment at 3 months revealed significant decreases in overall headache activity (50% or greater) in 7 subjects. Significant clinical or statistical prepost differences, or both, were also found for the number of headache-free days, peak headache activity, and medication index. This is the first prospective study of tension headache in an elderly population, and, unlike previous retrospective studies, it suggests that relaxation therapy may be an effective intervention in the treatment of such headaches.     

Body image,dieting tendencies,and sex role traits in urban black women

The present study examined body image satisfaction, dieting tendencies, and sex role traits among a sample of black urban women. While women who felt “too fat” were more likely than other women to engage in both restrictive and nonrestrictive dieting tendencies, in general, the women's body weight and body image did not compel them to utilize extremely restrictive dieting practices. A sizable proportion of the sample reported body image dissatisfaction and weight concerns, yet this did not appear to exert an overwhelmingly negative influence over other aspects of their lives, such as participation in sports, exercise, and sexual activity. Body image satisfaction and sex role traits were related. Dieting tendencies were also related with body image satisfaction. These findings and implications for further research are discussed.     

The ratio principle holds over a million-to-one range of illumination

Infant sensitivity to kinetic information specifying three-dimensional object shape was assessed using computer-generated random-dot displays. Four-month-old infants were habituated to displays of an object oscillating about two different axes on alternating trials. Following habituation, the infants were tested for recovery from habituation to a display of the same object and a novel object. Both test displays employed a new axis of rotation. The infants generalized habituation to the same object and increased their looking to the new object. These results provide evidence that infants are sensitive to motion-carried information specifying three-dimensional object shape, since the random-dot displays minimized static information that differentiated the two objects. These findings suggest that, at least by 4 months of age, infants can detect subtle differences in shape from purely kinetic information.