Experimental Personality Designs: Analyzing Categorical by Continuous Variable Interactions

Theories hypothesizing interactions between a categorical and one or more continuous variables are common in personality research. Traditionally, such hypotheses have been tested using nonoptimal adaptations of analysis of variance (ANOVA). This article describes an alternative multiple regression-based approach that has greater power and protects against spurious conclusions concerning the impact of individual predictors on the outcome in the presence of interactions. We discuss the structuring of the regression equation, the selection of a coding system for the categorical variable, and the importance of centering the continuous variable. We present in detail the interpretation of the effects of both individual predictors and their interactions as a function of the coding system selected for the categorical variable. We illustrate two- and three-dimensional graphical displays of the results and present methods for conducting post hoc tests following a significant interaction. The application of multiple regression techniques is illustrated through the analysis of two data sets. We show how multiple regression can produce all of the information provided by traditional but less optimal ANOVA procedures.     

Category typicality effects in episodic memory: Testing models of distinctiveness

Middle Tennessee State University, Murfreesboro, Tennessee Category typicality effects were investigated within the context of three models of distinctiveness: a univariate model, a fixed-multifeature model, and a weighted-multifeature model. High-typical, medium-typical, and atypical targets were embedded in lists containing a background set of mediumto high-typicality items. Atypical items were more poorly recalled than were medium- and high-typical items independently of list structure. In recognition, subjects who studied high-typical items had difficulty discriminating between high-typical items that were and were not presented as part of the list. However, item typicality had little effect on the recognition performance of subjects who did not study high-typical items. These findings were consistent with the weighted-multifeature model of distinctiveness.     

Ken and Barbie at life size

There has been considerable discussion in both the scientific literature and general media concerning the appropriateness of the body shape and proportions of the Ken and Barbie dolls, the most popular dolls in modern history. The greatest concern has been of the possible influence that these, and other cultural ideals for body shape, may have on young children. However, these concerns have been based entirely on the subjective interpretation of how one perceives the body dimensions of the dolls relative to an adult size. We therefore used our skills in anthropometry and the rules of allometry to scale the dolls to an adult height to determine the dimensions that these dolls would assume at this adjusted size. These were compared to actual proportions of several representative adult groups of predominantly Anglo-Australian males and females. The critics have been justified in their opinions since both Barbie and Ken are thin relative to the reference samples. Barbie's mean girth z-score relative to a reference cross-section of the young adult population was –4.2. This indicates that the probability for such a body shape is less than 1 in 100,000. Ken is more realistic at about 1 in 50.Special thanks to Melissa Clough, Brendon Dews, Loretta Downie, Judy Morris, and Kim Birchall.     

Religiosity and social desirability: impression management and self-deceptive positivity

The first aim of the present study was to replicate previous research, which has investigated the association between scores on the Francis Scale of Attitudes towards Christianity (FSAC) (Francis & Stubbs, 1987) and scores on Eysenck's Personality Questionnaire (EPQ-R Short Scale) (Eysenck & Eysenck, 1991). Further evidence is presented that higher religiosity is associated with lower scores on the psychoticism scale. The main aim of the present study, however, was to investigate the association between social desirability and religiosity. Although no association was found between religiosity and Lie scale scores in the present study, there is debate over what the Lie scale is actually measuring and so we also included, among other measures, the Balanced Inventory of Desirable Responding (BIDR: Paulhus, 1988), which consists of two subscales, self deceptive positivity and impression management. It was found that although religiosity was not associated with self-deception it was associated with impression management.     

Denial and self-denigration in the draw-a-person profiles of alcoholics

The present study attempts to cross-validate earlier findings that alcoholics tend to use more denial and are more demeaning of their characters than controls on the objective-projective Apperceptive Personality Test. One hundred nonalcoholic, nonpatient controls were matched to 100 outpatient alcoholics on age, race, and social class. All subjects were given the objective-projective Draw A Person Questionnaire, which was scored for 14 scales. As hypothesized and consistent with the earlier findings, alcoholics used more denial and were more often demeaning of their drawn characters than were controls. These and other exploratory findings are discussed.     

Efficacy of delayed auditory feedback for treating cluttering: Two case studies

Two clutterers were treated with similar preplanned delayed auditory feedback (DAF) procedures, using probe samples in which the DAF was not present to measure treatment efficacy. Whereas both clients met established fluency criteria during treatment, both clutterers had difficulty transferring gains to probe sessions—one more than the other. Differences in results of DAF treatment are discussed from the perspectives of differences in cluttering severity, coexisting disorders, and supplementary clinical techniques.     

Criterion validation of two approaches to performance appraisal: The behavioral observation scale and the relative percentile method

We compared the criterion validity of a new relative performance appraisal format (percentile-based ranking) to that of an absolute format (BOS) in a sample of 88 unit managers. Overall, our results suggest that the relative format has higher criterion-related validity than does the absolute format. These findings contradict conventional wisdom that format-related differences in measures of performance are minimal and that relative approaches to performance appraisal are inferior.This research was supported by grants from the Social Sciences and Humanities Research Council of Canada (SSHRC) to Richard D. Goffin, Douglas N. Jackson, John P. Meyer, Sampo V. Paunonen, and Mitchell G. Rothstein. Additional funding provided by a research grant from Imperial Oil Ltd. to Douglas N. Jackson.A version of these results was presented at the 7th Annual Meeting of the Society for Industrial and Organizational Psychology, Montreal, Canada, May, 1992. Limited portions of these data, addressing distinctly different research issues, were published in Gellatly, Paunonen, Meyer, Jackson, & Goffin (1991) and Meyer, Paunonen, Gellatly, Goffin, & Jackson (1989).     

Reducing REBT's “wince factor:” an insider's perspective

The author discusses three aspects of rational emotive behavior therapy (REBT) that occasionally make him wince. They are: REBT does not adequately address issues relating to diversity-sensitive counseling; there is a tendency for some REBT adherents to display poor interpersonal skills, and lack a philosophical commitment to the interdependence of humans on one another; and, there is a tendency for REBT to promise more than it can deliver. A list of 15 recommendations and wishes for a new and improved version of REBT are included.The author wishes to express his appreciation to Dominic DiMattia and Ellen Finkelstein who provided valuable suggestions to a draft version of this article and to Windy Dryden who initiated this dialog and saw it through to its publication.Stephen. G. Weinrach id a professor of counseling and human relations a,t Villanova University Villanova, PA and a Fellow of the Institute for Rational-Emotive Therapy in New York. He maintains a private practice in Havertown, PA.