Interrelationships of number-correct and limen scores for an amount-limit test

For an amount-limit test homogeneous as to content and varied as to difficulty it is established that an individual's number-right score and his limen score as estimated by the constant process are mathematically related. The experimental and the theoretic relationship between normal deviate and limen score are shown to be in good agreement. It is also found that the two methods of evaluating individual test performance yield equally reliable sets of scores for the procedures used. Accordingly where the assumptions basic to the relationship obtain, the more conveniently computed raw score may be considered to be as valid and reliable an index of individual test performance as the limen score. The concept of the dispersion parameter of the individual as a measure of change or error in test score found no experimental verification. Estimates of individual variability are unrelated to differences in score on equivalent forms.The writer gratefully acknowledges Lt. Colonel M. W. Richardson's invaluable counsel, Dr. H. Gulliksen's helpful suggestions, and Dr. H. H. Long's aid in administering the tests.     

The Effects of Limited and Conflicting Stereotypic information on Group Categorization in Northern Ireland1

The process of group categorization, as suggested by Tajfel and Turner's (1979) theory of intergroup comparison, was examined under conditions of intergroup conflict in Northern Ireland. The theory predicts that under “normal” conditions groups have a need to distinguish themselves from others. The present study investigates how individuals in Northern Ireland under extreme environmental pressures to identify both their own and other groups, can use learned stereotypic cues in making such categorizations. Results suggested that such limited information was highly effective in the process of categorization, with both Protestant and Catholic subjects exhibiting significant agreement and confidence in identifying unknown persons on the basis of stereotypic cues Conflicting information was found to reduce subject's confidence levels, with conflicting Catholic cues being more disruptive than Protestant ones     

An Evaluation of a School-Based Suicide Awareness Intervention

This study employed a self-report questionnaire in a Solomon four-groups design to assess the efficacy of suicide intervention classes in achieving their instructional objectives. Because adolescents are often the first to know of a peer's suicidal thoughts or plans, the goal of the classes was to increase the likelihood that students who come into contact with potentially suicidal peers can more readily identify them and will be consistently inclined to take responsible action on their behalf. Students who participated in the classes as compared to controls showed significant gains in relevant knowledge about suicidal peers and significantly more positive attitudes toward help seeking and intervening with troubled peers. Results of this study will be used to strengthen components of the lessons aimed at enhancing the likelihood of performance of responsible interventions     

Bayesian inference for the information gain model

One of the most popular paradigms to use for studying human reasoning involves the Wason card selection task. In this task, the participant is presented with four cards and a conditional rule (e.g., “If there is an A on one side of the card, there is always a 2 on the other side”). Participants are asked which cards should be turned to verify whether or not the rule holds. In this simple task, participants consistently provide answers that are incorrect according to formal logic. To account for these errors, several models have been proposed, one of the most prominent being the information gain model (Oaksford & Chater, Psychological Review, 101, 608–631, 1994). This model is based on the assumption that people independently select cards based on the expected information gain of turning a particular card. In this article, we present two estimation methods to fit the information gain model: a maximum likelihood procedure (programmed in R) and a Bayesian procedure (programmed in WinBUGS). We compare the two procedures and illustrate the flexibility of the Bayesian hierarchical procedure by applying it to data from a meta-analysis of the Wason task (Oaksford & Chater, Psychological Review, 101, 608–631, 1994). We also show that the goodness of fit of the information gain model can be assessed by inspecting the posterior predictives of the model. These Bayesian procedures make it easy to apply the information gain model to empirical data. Supplemental materials may be downloaded along with this article from .     

Gender recognition from point-light walkers

Point-light displays of human gait provide information sufficient to recognize the gender of a walker and are taken as evidence of the exquisite tuning of the visual system to biological motion. The authors revisit this topic with the goals of quantifying human efficiency at gender recognition. To achieve this, the authors first derive an ideal observer for gender recognition on the basis of center of moment (J. E. Cutting, D. R. Proffitt, & L. T. Kozlowski, 1978) and, with the use of anthropometric data from various populations, show optimal recognition of approximately 79% correct. Next, they perform a meta-analysis of 21 experiments examining gender recognition, obtaining accuracies of 66% correct for a side view and 71% for other views. Finally, results of the meta-analysis and the ideal observer are combined to obtain estimates of human efficiency at gender recognition of 26% for the side view and 47% for other views.     

Depression After Traumatic Brain Injury: A Review of Evidence for Clinical Heterogeneity

Depression represents a major source of disability among individuals who have suffered a traumatic brain injury (TBI), with estimates of prevalence in this population ranging over 50%. In comparison with other sequelae of TBI, depression is often poorly conceptualized and treated among acute care and rehabilitation professionals. One reason for this is the lack of clear etiological models for the development of depression following TBI. This paper argues that post-TBI depression actually represents a heterogeneous category, with multiple etiologic pathways and clinical implications. The literature in this area is reviewed, with an emphasis on an appreciation of the diversity within this clinical population. Conclusions focus on suggestions for differential diagnosis and treatment options.     

The Influence of Physical Attractiveness and Gender on Ultimatum Game Decisions

Physical appearance influences behavior in a number of environments, yet surprisingly little is known about the influence of physical attractiveness on the bargaining process. We conducted an ultimatum game experiment to investigate the influence of physical attractiveness and gender on ultimatum game decisions. Results from this study revealed no significant differences in the offers or demands attractive and unattractive people made. However, attractive people and men were treated differently by others. Consistent with the notion of a “beauty premium,” attractive people were offered more, but more was demanded of them. Men were also offered more, and less was demanded of them. We discuss implications of these results with respect to bargaining and the labor market.     

Objective self-awareness,standards of evaluation,and moral behavior

In a performance setting, subjects were given an opportunity to cheat without fear of detection on puzzle problems. Subjects were led to believe that successful performance was due to ability in some conditions, but to luck in other conditions. In fact, most of the problems were insolvable, so that success was impossible without cheating. Self-awareness was induced in half the subjects by having them sit in front of a mirror and listen to a tape recording of their own voice as they worked on the puzzle problems; the remaining subjects were not exposed to a mirror and listened to a tape of someone else's voice as they worked on the problems. It was predicted that cheating frequency would be higher under ability attribution conditions than under luck attribution conditions, and that this effect of performance attribution would be greater among self-aware subjects than among non-self-aware subjects. Results confirmed these hypotheses. Discussion centered on the differential use of morality and competence standards for behavior when in a state of self-awareness.     

Deterring the Onset of Smoking in Children: Knowledge of Immediate Physiological Effects and Coping with Peer Pressure,Media Pressure,and Parent Modeling1

Entering seventh grade, most children believe that smoking endangers their long-term health. Nevertheless, three sources of social pressure were found to often have an overriding influence to begin smoking: peers, models of smoking parents, and media. Interventions were developed to train children to cope with these pressures. Also stressed were immediate rather than long-term physiological effects of smoking. A dependent measure was utilized that generates increased validity of self-reports of smoking. A 10-week investigation was completed with 750 male and female students entering the seventh grade. Rates of onset of smoking in treatment groups were significantly lower than in a pretest-single posttest control group.