Social categorization and attitude change

Two experiments were carried out investigating the effect of categorization on attitude change. It was predicted that the division of a number of individuals into two subgroups (categorization), in such a way that initial attitudes correlate with subgroup membership, would lead to accentuation of attitudinal differences between subgroups. It was further predicted that an identical distribution of initial attitudes without superimposed categorization would lead to convergence of attitude positions. In experiment 1, the effect of a male-female classification on attitude change was studied. It was indeed found that subjects changed their attitudes in the direction opposite to the position of the outgroup (intergroup attitude differentiation), but only for groups who were initially more extreme than the comparison group. In the control condition (no categorization), conformity effects were observed. In experiment 2, an antagonistic intergroup setting was induced. In this situation, strong intergroup attitude differentiation effects were observed, which were not affected by the magnitude of the initial intergroup discrepancy. In the control condition, subjects did not show conformity to the overall group mean, but maintained their initial noncentral attitude position.     

Examining differential item functioning due to item difficulty and alternative attractiveness

A method for analyzing test item responses is proposed to examine differential item functioning (DIF) in multiple-choice items through a combination of the usual notion of DIF, for correct/incorrect responses and information about DIF contained in each of the alternatives. The proposed method uses incomplete latent class models to examine whether DIF is caused by the attractiveness of the alternatives, difficulty of the item, or both. DIF with respect to either known or unknown subgroups can be tested by a likelihood ratio test that is asymptotically distributed as a chi-square random variable.     

Alternating least squares algorithms for simultaneous components analysis with equal component weight matrices in two or more populations

Millsap and Meredith (1988) have developed a generalization of principal components analysis for the simultaneous analysis of a number of variables observed in several populations or on several occasions. The algorithm they provide has some disadvantages. The present paper offers two alternating least squares algorithms for their method, suitable for small and large data sets, respectively. Lower and upper bounds are given for the loss function to be minimized in the Millsap and Meredith method. These can serve to indicate whether or not a global optimum for the simultaneous components analysis problem has been attained.Financial support by the Netherlands organization for scientific research (NWO) is gratefully acknowledged.     

Penalized optimal scaling for ordinal variables with an application to international classification of functioning core sets

Ordinal data occur frequently in the social sciences. When applying principal component analysis (PCA), however, those data are often treated as numeric, implying linear relationships between the variables at hand; alternatively, non-linear PCA is applied where the obtained quantifications are sometimes hard to interpret. Non-linear PCA for categorical data, also called optimal scoring/scaling, constructs new variables by assigning numerical values to categories such that the proportion of variance in those new variables that is explained by a predefined number of principal components (PCs) is maximized. We propose a penalized version of non-linear PCA for ordinal variables that is a smoothed intermediate between standard PCA on category labels and non-linear PCA as used so far. The new approach is by no means limited to monotonic effects and offers both better interpretability of the non-linear transformation of the category labels and better performance on validation data than unpenalized non-linear PCA and/or standard linear PCA. In particular, an application of penalized optimal scaling to ordinal data as given with the International Classification of Functioning, Disability and Health (ICF) is provided.     

Effects of rate of reinforcement-time upon concurrent operant performance

Three experiments were conducted to investigate the theoretical reduction of rate and duration of reinforcement to their product, rate of reinforcement-time, under concurrent chain schedules. In Exp. I, rate of reinforcement-time was varied by varying rate of reinforcement delivery, holding duration of reinforcement availability constant; in Exp. II, rate of reinforcement-time was varied by holding rate of reinforcement delivery constant and varying duration of reinforcement availability; in Exp. III, rate of reinforcement-time was held constant by varying both rate and duration of reinforcement simultaneously and inversely. For all three experiments, both relative rate of responding and relative time spent in the initial link were found to match approximately the relative rate of reinforcement-time arranged in the terminal link. These data were interpreted as support for the notion that rate and duration of reinforcement may be functionally equivalent and reducible to a single variable, rate of reinforcement-time.     

Procedural fairness and self-esteem

We argue that people's self-esteem is affected by the fairness of procedures to which they are subjected; unfair treatment will lower self-esteem. Moreover, since this influence on self-esteem is presumably due to the implicit evaluation expressed by the choice of procedure and hence by the evaluation expressed by the person implementing the procedure, people's concern with the fairness of treatment will be focused on the interactional aspects of the procedure. In two experiments designed to test these hypotheses subjects received either a high or a low grade on an ability test on the basis of either fair or unfair grading procedures. The results of Experiment 1 indicated that subjects' self-esteem was lower after unfair treatment, and this influence was only apparent when subjects received high test feedback. Additionally, ratings of the fairness of the interaction were lower following unfair grading procedures. Experiment 2 also manipulated level of involvement with the test. Self-esteem was affected by procedural fairness and procedural fairness influenced perceived fairness of the interaction only in the high involvement condition.     

Racial categorization and preference among older children in The Netherlands

In this study the pervasiveness of racial categorization is investigated among children (10–12 years of age) in multi-racial schools. Subjects were asked to sort photographs of unknown contemporaries and to indicate preferences. Skin colour, sex and facial expression were used as three characteristics which varied systematically in the pictures. The results show, first, that children preferred to use different features simultaneously instead of a single feature only. Second, in a dichotomous classification task skin colour and sex were the most obvious visible features used for categorization. Gender was also used for explaining socially undesirable behaviour, and for indicating preferences. while race was not used in these tasks. In indicating preferences facial expression and not skin colour was used as a subordinate category. There were very few differences between ethnic Dutch, coloured and ethnic minority children in the use of skin colour or other features.