The interaction of payoff structure and regulatory focus in classification

This report brings together research on motivation and learning by exploring how fit of regulatory focus affects people's ability to acquire new categories. Perceptual categories were learned by people with a promotion focus (a situationally determined sensitivity to gains) or a prevention focus (a sensitivity to losses). Classification performance was closest to optimal (as determined by models fit to individual subjects' data) when the regulatory focus matched the structure of the payoffs for the categories. Promotion-focus subjects performed best when the payoffs consisted of all gains. Prevention-focus subjects performed best when the payoffs consisted of all losses.     

Linear transformations of the payoff matrix and decision criterion learning in perceptual categorization

The effects of payoff-matrix multiplication, payoff-matrix addition, the presence of long-run gains versus long-run losses, category discriminability, and base rate on decision criterion learning were examined in 2 perceptual categorization experiments. Observers were found to be sensitive to the effects of payoff-matrix multiplication (and category discriminability) on the steepness of the objective reward function in line with predictions from the flat-maxima hypothesis and contrary to the predictions from the payoff-variance hypothesis. Decision criterion learning was best in base-rate conditions, was worst when losses were associated with incorrect responding, and was intermediate when no losses were associated with incorrect responding. This performance profile was well captured by the competition between reward and accuracy (COBRA) hypothesis. A hybrid model framework that instantiates both the flat-maxima and COBRA hypotheses was necessary to account for the data from both experiments.     

Conformity to experimenter-determined,payoff enforced criterion levels in the method of random staircases

Results obtained from Ss paid to meet arbitrary criteria are compared with ordinary determinations of limens for increments of white noise in a constant background of white noise. Multiple random, yes-no staircases are used. It is demonstrated that a S can reliably exhibit a variety of arbitrarily determined “thresholds” when appropriate pay-off contingencies are introduced.     

The minimal group paradigm: Categorization into two versus three groups

The minimal group paradigm (Tajfel, Billig, Bundy and Flament, 1971) has been influential in the study of intergroup relations. Thus far, most minimal group experiments have divided the subjects either into two groups, or have categorized them on two separate dichotomous dimensions in cross-categorization experiments. This study examines the minimal group paradigm using three distinct and independent groups. Comparison of the results with three minimal groups with those of a baseline two-group experiment shows that with a three-group structure there is no significant ingroup bias. It is suggested that the two-group minimal group experiment shows ingroup bias because subjects access a dichotomous categorization, and that this dichotomous categorization primes a competitive orientation. A two-group context may be particularly efective in evoking an ‘us versus them’ contrast. Self-categorization as a group member is more likely to occur in the presence of two groups whereas three minimal groups renders an ‘us–them’ contrastive orientation less salient. The absence of intergroup discrimination found in the present minimal group study may be limited to the behaviour of minimal or artificially created groups. In the real world of intergroup relations discrimination towards multiple outgroups is a well-known phenomenon. While this study should be regarded as only preliminary research, further elaboration and specification of the conditions under which multiple group contexts may hinder intergroup discrimination is required.     

A theoretical framework for understanding the effects of simultaneous base-rate and payoff manipulations on decision criterion learning in perceptual categorization

Observers completed perceptual categorization tasks in which base rates and payoffs were manipulated separately or simultaneously across a range of category discriminabilities. Decision criterion estimates from the simultaneous base-rate/payoff conditions were closer to optimal than those predicted from the independence assumption, in line with predictions from the flat-maxima hypothesis. A hybrid model that instantiated the flat-maxima and competition between reward and accuracy maximization hypotheses was applied to the data as well as used in a reanalysis of C. J. Bohil and W.J. Maddox's (2001) study. The hybrid model was superior to a model that incorporated the independence assumption, suggesting that violations of the independence assumption are to be expected and are well captured by the flat-maxima hypothesis, without requiring any additional assumptions.     

Characteristics attributed to individuals on the basis of their first names

Characteristics connoted by first names were explored in 7 studies. Four factors were identified: Ethical Caring, Popular Fun, Successful, and Masculine-Feminine (Study 1, N = 165). Men's names connoted more masculine characteristics, less ethical caring, and more successful characteristics than did women's names (Study 2, N = 274). Nicknames connoted less successful characteristics, more popular fun, and less ethical caring characteristics than did given names (Study 3, N = 289). Androgynous names connoted more popular fun and less masculine characteristics for men and more popular fun, less ethical caring, and more masculine characteristics for women than did gender-specific names (Study 4, N = 378). Less conventionally spelled names connoted uniformly less attractive characteristics (Study 5, N = 145). For men only, longer names connoted more ethical caring, less popular fun, more successful, and less masculine characteristics (Study 6, N = 620). More anxiety and neuroticism were attributed to those with less common names and more exuberance was attributed to those with more attractive names (Study 7, N = 137).     

Projection of a binary criterion into a model of hierarchical classes

A formal analysis is made of how to project an attribute criterion into the hierarchical classes model for object by attribute data proposed by De Boeck and Rosenberg. The projection is conceptualized as the prediction of the attribute criterion by means of a logical rule defined on the basis of attribute combinations from the model. Eliminative and constructive strategies are proposed to find logical rules with maximal predictive power and minimal formula complexity. Logical analyses of a real data set are reported and compared with a logistic regression to demonstrate the usefulness of the logical strategies, and to show the complementarity of logical and probabilistic approaches.The first suthor is Senior Research Assistant of the National Fund for Scientific Research (Belgium). We would like to thank the Editor, the reviewers, Seymour Rosenberg, and Luc Delbeke for their helpful comments on earlier drafts of this article.     

Note on use of extreme criterion groups in item discrimination analysis

The purpose of this note is to reconsider the Kelley-Cureton definition of optimal extreme groups for estimating item-criterion correlations. Optimal tail per cents are derived, using the criterion of minimum sampling variance of the tetrachoric correlation coefficient, and the findings are related to earlier work of Mosteller. It is shown that upper and lower 27 per cent groups yield the most precise estimate of the tetrachoric coefficient only when the population correlation is close to zero. When the population value is .4, extreme 20 per cent groups provide estimates with the smallest sampling error variance. It is further shown, however, that 27 per cent extremes yield highly efficient estimates. Thus no change is recommended in traditional item analysis procedures.     

Responsibility attribution by groups and individuals: The effects of the interaction episode

Studied the effects of formal and informal interaction styles on the extremity of responsibility attribution judgements by groups. The stimuli were eight scenarios describing typical ‘life dilemmas’, incorporating the manipulation of the following two variables in a 2 × 2 design: (a) the risky-cautious decision taken by the actor in response to the dilemma, and (b) the outcome of the decision (success-failure). Subjects (N = 130) provided judgements about the attributed responsibility of the actor, and their perception of the actor and the situation first as individuals, followed by (a) formal or (b) informal group discussion, leading to consensus judgements. Results showed that group attributions were significantly more extreme than individual attributions, but only following the informal group interaction. The actors' riskiness and success were also significantly related to the size of the extremity shift. The findings are discussed in terms of the importance of the social context and the specific interaction episode in attribution judgements, and the possible implications of the results for such real life decision-making groups as committees and interviewing panels are considered.     

Crossing at a red light: Behaviour of individuals and groups

The present study examines the road behaviour of individual pedestrians at an intersection with a traffic signal compared to groups of pedestrians at the same intersection.In total, 1392 pedestrians were unobtrusively observed in an urban setting at a pedestrian street crossing of undivided streets; 842 were female (60.5%) and 550 were male (39.5%). The observations took place between 7:30 and 8:30 in the morning. Chi-square test revealed the males crossed on red more frequently than females. Logistic regression predicting red-light crossing for pedestrians arriving during a red-light phase indicated that, apart from gender, the tendency to cross on red was greater when there were fewer people waiting at the curb, either when a pedestrian arrived, or joining after arrival. The discussion refers to the theoretical explanations concerning the theory of ‘social control’ and to some practical implications of the results, such as using the positive value of social control in media campaigns and adjusting the red light duration in order to encourage people to obey the traffic light.     

Bridging psychology and biology. The analysis of individuals in groups

Biological systems are particularly prone to variation, and the authors argue that such variation must be regarded as important data in its own right. The authors describe a method in which individual differences are studied within the framework of a general theory of the population as a whole and illustrate how this method can be used to address three types of issues: the nature of the mechanisms that give rise to a specific ability, such as mental imagery; the role of psychological or biological mediators of environmental challenges, such as the biological bases for differences in dispositional mood; and the existence of processes that have nonadditive effects with behavioral and physiological variables, such as factors that modulate the response to stress and its effects on the immune response.     

Criterion-related validity of a new classification scheme for institutionalized mentally retarded individuals

Two studies were carried out to test the validity of a new three-cluster classification scheme. The association of cluster membership with both clients' movement and program placement was significant, but only in the case of the latter criterion was prediction improved by knowledge of a client's cluster membership.     

Variation in cortical evoked responses as a function of performance criterion

Averaged evoked cortical responses (CER) from the scalp of human Ss were recorded within an experimental paradigm that permitted the performance criterion to be varied. The signals evoking the cortical responses were contingent upon S’s pressing a button to bisect a temporal interval within certain tolerance limits. Under passive conditions averaged response waveforms lacked a second, late component that became prominent under temporal bisection conditions. The late component P² - N² increased regularly in magnitude as the performance criterion was made more stringent. The effect of performance criterion on the earlier component, N¹ - P², was neither as large nor as systematic as that shown by P² - N².     

The ingroup bias as a function of differences in resources within groups

Subjects were led to believe that two sub-groups were created according to similarity. Then they were assigned resources, received bogus offers, and asked to negotiate a mutually acceptable reward division. It was found that low resource members negotiated payoffs approximately equally. In contrast, high resource members negotiated larger payoffs to themselves when paired with outgroup members.     

The function of the therapist's affect in therapeutic conflict in groups

Group psychotherapy theory and technique are presented with the goals of helping group practitioners working with difficult clients: 1) develop a treatment plan; 2) create a therapeutic alliance; 3) foster a responsive group climate; and 4) utilize the therapist's countertransferential reactions in dealing with therapeutic conflict. Historical modifications of the analyst's role in the development of group psychotherapy are noted. Emphasis is give to the recognition of therapist-client identifications in order to separate feelings induced in the therapist from countertransferential reactions, to enable the practitioner to respond appropriately to the affective and inspirational substratum of therapeutic groups.