MMPI-2 profile code types and measurement error

We studied simulated MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) code type stability and change expected with measurement error for 12 MMPI-2 well-defined mean code type profiles. Profile scores for the 2 scales defining the code type were systematically varied to represent target code type profiles at 9 different levels of T-score profile definition. We randomly generated samples of 50 simulated, estimated true score profiles at each level of profile definition for each code type around the estimated true scores for each scale at each level of profile definition. Two sets of simulated profiles were developed. The first simulation was based on the reported means, test-retest reliabilities, and the standard errors of measurement for the MMPI-2 normative group. The second simulation was based on the means, standard deviations, and estimated retest stability for a clinical group of psychiatric patients. We calculated frequencies and percentages of simulated profiles with the highest estimated true scores on the same 2 scales as the original code type profile. Percentages of simulated profiles with the same 2 highest scales as the original code type profiles increased from 27% to 37% for the 3-point level of definition, 37% to 49% for the 5-point definition, 46% to 61% for 7-point definition, 63% to 78% for 10-point definition, 78% to 89% for 13-point definition, 83% to 93% for 15-point definition, and greater than 90% for profile definition greater than 15 points.     

Resolution of conflicts between internal and external information sources on a time reproduction task: the role of perceived information reliability and attributional style

Erroneous knowledge of results (KR) that conflicts with other internal or external information sources is preferentially used and misguides performance on motor and mental timing tasks. Buekers et al. [J. Motor Behavior 26 (1994) 27] hypothesized that KR is used preferentially because participants deem it to be the most reliable information source. We tested this hypothesis in two experiments. We manipulated subjective reliability of information and information content and demonstrated that both reliability and content are assessed and used. In a third experiment we examined whether attributional style affected the use of internal and external information. While KR was present, attributional style was unrelated to performance. However, when erroneous KR was withdrawn, participants who scored high in internal attributional style or high in controllability showed more accurate performance. Whereas evaluation of information quality is explicit, information provided by the KR, whether accurate or not, may influence both implicit and explicit aspects of the tasks.     

The developmental ecology of urban males' youth violence

Data from a longitudinal study of 294 African American and Latino adolescent boys and their caregivers living in poor urban communities were used to test a developmental-ecological model of violence. Six annual waves of data were applied to evaluate the relations between microsystem influences of parenting and peer deviance (peer violence and gang membership), macrosystem influences of community structural characteristics and neighborhood social organization, and individual involvement in violence (level and growth). Structural equation modeling analyses showed that community structural characteristics significantly predicted neighborhood social processes. Parenting practices partially mediated the relation between neighborhood social processes and gang membership. Parenting practices was fully mediated in its relation to peer violence by gang membership. Gang membership was partially mediated by peer violence level in its relation to individual violence level. Although the overall set of relations does not satisfy mediation requirements fully in all instances, the model was validated for the most part, supporting a focus on a multilevel ecological model of influences on risk development.     

Do age of onset and course of illness define biologically distinct groups within atypical depression?

Illness course separates patients with atypical depression into tricyclic responders and nonresponders as does perceptual asymmetry. The authors therefore investigated whether the course-of-illness parameters would define groups within atypical depression differing in brain laterality. Patients with atypical depression were assessed for illness course and brain laterality. Two patient groups were defined, 1 with onset prior to age 20 plus a very chronic course, and a 2nd group having later onset or less chronic illness. Patients reporting early onset of very chronic dysphoria showed significantly less right-ear (left-hemisphere) accuracy and also differed in characteristic perceptual asymmetry when compared to patients with later onset or less chronicity. Course of illness may usefully define more homogeneous depressive subgroups within atypical depression.     

The time course and significance of cannabis withdrawal

Withdrawal symptoms following cessation of heavy cannabis (marijuana) use have been reported, yet their time course and clinical importance have not been established. A 50-day outpatient study assessed 18 marijuana users during a 5-day smoking-as-usual phase followed by a 45-day abstinence phase. Parallel assessment of 12 ex-users was obtained. A withdrawal pattern was observed for aggression, anger, anxiety, decreased appetite, decreased body weight, irritability, restlessness, shakiness, sleep problems, and stomach pain. Onset typically occurred between Days 1-3, peak effects between Days 2-6, and most effects lasted 4-14 days. The magnitude and time course of these effects appeared comparable to tobacco and other withdrawal syndromes. These effects likely contribute to the development of dependence and difficulty stopping use. Criteria for cannabis withdrawal are proposed.     

The use of latent trajectory models in psychopathology research

Despite the recent surge in the development of powerful modeling strategies to test questions about individual differences in stability and change over time, these methods are not currently widely used in psychopathology research. In an attempt to further the dissemination of these new methods, the authors present a pedagogical introduction to the structural equation modeling based latent trajectory model, or LTM. They review several different types of LTMs, discuss matching an optimal LTM to a given question of interest, and highlight several issues that might be particularly salient for research in psychopathology. The authors augment each section with a review of published applications of these methods in psychopathology-related research to demonstrate the implementation and interpretation of LTMs in practice.     

Effects of the terrorist attacks of 9/11/01 on employee attitudes

Much has been stated in the popular press about the effects of the events of 9/11/01 on employee attitudes about work. This study examined a large sample (N = 70,671) of employees of a multinational manufacturer whose annual employee survey data collection was interrupted by the events. After demonstrating measurement equivalence across time and countries, changes in attitudes pre- and post-9/11 were examined. Only negligible differences were found in Job Satisfaction, Supervisor Evaluation, Stress, and Organizational Commitment to Diversity for U.S. employees or for employees worldwide. Demographic differences in response to events were not found. Implications for understanding effects of stressful external events on employee perceptions of work are discussed.     

Does right-left prevalence occur for the Simon effect?

In four experiments, we investigated whether a right-left prevalence effect occurs for the Simon task, in which stimulus location is irrelevant, when the stimulus and the response sets vary along horizontal and vertical dimensions simultaneously. Simon effects were evident for both dimensions, and they were of similar magnitude, indicating no prevalence effect. Manipulations of the relative salience of the dimensions for the stimulus and the response sets resulted in a larger Simon effect for the more salient dimension than for the less salient one, but there was no overall prevalence effect. The results indicate that manipulations of salience affect the relative magnitudes of automatic response activation for the vertical and the horizontal dimensions but that the right-left prevalence effect is due to a coding bias in intentional response selection processes when stimulus location is relevant.