Internal Validity of the Disruptive Behavior Disorder Symptoms: Implications from Parent Ratings for a Dimensional Approach to Symptom Validity

A dimensional approach was used to evaluate the internal validity of the DSM-III-R ADHD-inattention, ADHD-hyperactivity/impulsivity, oppositional defiant disorder (ODD), and conduct disorder (CD) symptoms (i.e., whether a symptom has a stronger correlation with its own dimension than the other three). Parents rated 4,019 children between the ages of 2 and 19 on these symptoms. The results showed that 5 of the 6 inattention symptoms, 3 of the 4 hyperactivity symptoms, 1 of the 4 impulsivity symptoms, 6 of the 9 oppositional defiant disorder symptoms, and 8 of the 11 CD symptoms had significant internal validity. Confirmatory factor analysis (CFA) found support for inattention, hyperactivity/impulsivity, oppositional defiant, and conduct disorder dimensions. Multiple-group CFA also found support for factor pattern and loading invariance across gender. The implications of these results as well as the merits of the dimensional approach to symptom validity are discussed in the context of the DSM-IV changes in ADHD, ODD, and CD.     

The life events scale for students: Validation for use with British samples

The life events scale for students is a checklist measure of life events intended for use with undergraduate populations. The report describes the validation of the scale for use with British undergraduates. Ratings for the events on the scale were obtained from a sample of 191 undergraduates. A second analysis using a sample of 40 undergraduates showed that scores on the scale were predictive of elevated levels of psychopathology. Furthermore, this relationship was largely independent of negative affectivity or repression-sensitization. The Life Events Scale for Students provides a suitable measure for use in stress research using undergraduate populations.     

The role of information in the emission of observing responses: a test of two hypotheses

Pigeons were trained on a trial procedure in a Skinner box. Each trial began with a fixed-interval schedule. Responding on this schedule produced a stimulus and a delayed trial outcome. The stimulus signalled whether the forthcoming outcome was reinforcement or nonreinforcement. Thus, the response was an observing response. When reinforcement was the outcome on 20% of the trials, response rates in the fixed interval were higher than when reinforcement was the outcome on 80% of the trials. This result is consistent with the hypothesis that observing responses are reinforced by the information associated with the stimulus signalling reinforcement. The result seems inconsistent with the hypothesis that observing responses are also reinforced by the information associated with the stimulus signalling nonreinforcement.     

Measuring the importance of information in judgment: Individual differences in weighting ability and effort

Measuring the importance of cues in social judgment has been a longstanding problem. Past research has shown individual differences in the impact of ability and study effort on judgments of student performance. This research examined the hypothesis that the individual differences are due to the weight given to the information as opposed to the perceived extremity of the values of the information. Subjects judged the performance of hypothetical students described by ability, study effort, and effort during an exam. Individual differences in the impact of the three types of information were obtained and were predictable from self-reports of the relative importance of information. Different values of weights were necessary to account for the differences in the impact of information, although there were also differences in the perceived extremity of the information. The theoretical and applied significance of distinguishing the weight given to information in judgment from its subjective value are discussed. On the basis of a new review of the literature, as well as the present results, it is concluded that self-reports of the relative importance of information are predictive of individual differences in information use in judgment, but that they may reflect the total impact of information rather than only the weight.     

Necessary versus sufficient causal schemata: Attributions for achievement in difficult and easy tasks

Previous research on Kelley's schemata for multiple sufficient and multiple necessary causes has failed to examine the hypothesis that a schema influences both predictions of an event and attributions of its causes. This research examined the effects of the difficulty of a hypothetical exam on predictions of exam grades, and on attributions of ability and effort. Exam difficulty influenced both the pattern of judgments of grades and reported beliefs in multiple necessary versus multiple sufficient causes. Contrary to the predictions of the schema theory, exam difficulty had little influence on the pattern of attributions of ability and effort. Kelley's concept of a causal schema is reinterpreted in terms of current views of human judgment, and the possible implications of the data for the interpretations of a causal schema are examined. The results question the assumption that attributions are based on beliefs about how causes combine to determine an effect, and suggest further research on the relationship between predictions and attributions.     

Ingroup bias as a function of salience,relevance, and status: An integration

This paper reports the results of a meta-analytic integration of the results of 137 tests of the ingroup bias hypothesis. Overall, the ingroup bias effect was highly significant and of moderate magnitude. Several theoretically informative determinants of the ingroup bias effect were established. This ingroup bias effect was significantly stronger when the ingroup was made salient (by virtue of proportionate size and by virtue of reality of the group categorization). A significant interaction between the reality of the group categorization and the relative status of the ingroup revealed a slight decrease in the ingroup bias effect as a function of status in real groups, and a significant increase in the ingroup bias effect as a function of status in artificial groups. Finally, an interaction between item relevance and ingroup status was observed, such that higher status groups exhibited more ingroup bias on more relevant attributes, whereas lower status groups exhibited more ingroup bias on less relevant attributes. Discussion considers the implications of these results for current theory and future research involving the ingroup bias effect.     

The use of the large-scale integrated sensor (LSI) to estimate energy expenditure

The relationship between activity counts from the large-scale integrated sensor (LSI), placed at the hip and ankle, and heart rate-estimated energy expenditure was examined in three nonobese males during three conditions: normal morning activities, a 1-mi walk, and a 2-mi walk. Results showed that estimated caloric expenditure was related to activity counts for both monitoring placements, with correlations between counts and energy expenditure exceedingr=.90. These results show that energy expenditure in the activities sampled can be reliably estimated using activity monitors.This research was supported in part by a grant provided by The John D. and Catherine T. MacArthur Foundation Research Network on the Psychobiology of Depression, Clinical Research Center Grant 5-30915 from the NIMH, and Grant HD 16411 from the NICHD awarded to Dr. Epstein.     

Auditory spatial responses of young guinea pigs (Cavia porcellus) during and after ear blocking

Newborn guinea pigs were tested to determine their ability to approach an auditory stimulus early in development. Observations of the behavior of 1-4-day-old animals in a circular eight-choice maze revealed a pronounced tendency to orient toward and approach a tape-recorded signal of guinea pig vocalizations. The occurrence of approach responses was reduced to chance in animals tested with one ear occluded by wax ear plugs which attenuated but did not totally eliminate sound. The effect of monaural ear blocks was more severe than binaural blocks, which reflects the importance of binaural cues in the maintenance of approach responses to sound. In a second study, the ability of older animals, 11-31 days of age, was examined. Directional approach responses to sound were also evident at this age, and ear plugs disrupted performance only under monaural conditions. Furthermore, in animals raised from birth with monaural ear blocks but tested without ear plugs, there was a subsequent disruption of performance for at least 21 days. These results indicate the importance of binaural cues in the development of early auditory spatial responses and suggest the need for appropriate binaural experience for subsequent localization of sounds.     

Memory for impasses during problem solving

Three experiments were conducted to investigate the relative memorability of solved versus unsolved problems in long-term memory. In each experiment, subjects worked on a set of potentially solvable word problems, with the time spent on each problem held constant. Problem memorability was then measured with a free-recall task. In Experiment 1, in which a majority of problems were solved, unsolved problems were better remembered. In Experiments 2 and 3, we expanded on these results by manipulating problem difficulty and thus the ratio of solved to unsolved problems. When unsolved problems were as frequent as or more frequent than solved problems, no memory differences were found. Across all three experiments, the ratio of solved to unsolved problems was found to be a significant predictor of unsolved-problem memorability, but was not significantly related to the memorability of solved problems. The results illustrate that when impasses in problem solving are infrequent, they are more available in memory than are solved problems. It is speculated that this memory phenomenon may facilitate the recognition of opportunities to return to problems that have been terminated short of solution.