Political Power and Race Relations in South Africa: African Attitudes Before and After the Transition

When an oppressed majority finally gains political power, what happens to its attitudes to its erstwhile oppressor, and to its perceptions and feelings about its socioeconomic disadvantages that were established during its oppression? Longitudinal data from pre- and post-transition surveys of black South African college and high school students indicate marked reductions in perceptions of and outrage about intergroup socioeconomic inequity and deprivation relative to English-speaking and Afrikaans-speaking whites, but no change in attitudes toward these groups or toward whites in general. The findings are discussed in terms of contemporary theory and research on justice, intergroup relations, and group conflict. Some tentative implications for the prospects for a democratic political culture in South Africa are noted.     

Intergroup contact between professional groups: Two evaluation studies

We report two studies which evaluate practically-oriented programmes of interprofessional contact involving doctors and social workers. The evaluation is based on the ‘contact hypothesis’ in intergroup relations, and highlights four sets of dependent measures: background perceptions, ingroup and outgroup ratings, knowledge, and judgements about work with outgroup partners and experienced contact. Consistent with the contact hypothesis, both studies revealed an improvement in outgroup attitudes, evidence of mutual intergroup differentiation (acknowledged superiority of ingroup and outgroup on independent dimensions), and increased outgroup knowledge. Greater change in Study 2 is interpreted in terms of its longer duration, and the opportunity it provided for contact with multiple outgroup members, compared with a single outgroup partner in Study 1. These findings from field studies are consistent with results from published laboratory experiments.     

Linear relations amongk sets of variables

A family of solutions for linear relations amongk sets of variables is proposed. It is shown how these solutions apply fork=2, and how they can be generalized from there tok3.The family of solutions depends on three independent choices: (i) to what extent a solution may be influenced by differences in variances of components within each set; (ii) to what extent the sets may be differentially weighted with respect to their contribution to the solution—including orthogonality constraints; (iii) whether or not individual sets of variables may be replaced by an orthogonal and unit normalized basis.Solutions are compared with respect to their optimality properties. For each solution the appropriate stationary equations are given. For one example it is shown how the determinantal equation of the stationary equations can be interpreted.     

A note on dual scaling of successive categories data

Three methods for dual scaling of successive categories data are formulated. They are mathematically equivalent, and provide an appropriate technique to determine stimulus values and category boundaries on a joint scale, a problem that Nishisato's method (1980a) failed to handle. This study was supported by the Natural Sciences and Engineering Research Council of Canada (Grant No. A7942) to S. Nishisato. Comments on the earlier draft from anonymous reviewers were most helpful and much appreciated.     

The transfer of specific and general consequential functions through simple and conditional equivalence relations

The purpose of this study was to examine the transfer of consequential (reinforcement and punishment) functions through equivalence relations. In Experiment 1, 9 subjects acquired three three-member equivalence classes through matching-to-sample training using arbitrary visual forms. Comparison stimuli were then given conditioned reinforcement or punishment functions by pairing them with verbal feedback during a sorting task. For 8 of the 9 subjects, trained consequential functions transferred through their respective equivalence classes without additional training. In Experiment 2, transfer of function was initially tested before equivalence testing per se. Three of 4 subjects showed the transfer without a formal equivalence test. In Experiment 3, 3 subjects were given training that gave rise to six new three-member conditional equivalence classes. For 2 of the subjects, the same stimulus could have either a reinforcement or punishment function on the basis of contextual cues that defined its class membership. Experiment 4 assessed whether equivalence training had established general or specific consequential functions primarily by adding novel stimuli in the transfer test. Subjects treated even novel feedback stimuli in the transfer test as consequences, but the direction of consequential effects depended upon the transfer of specific consequential functions through equivalence relations.     

Discrimination of response-reinforcer and response-stimulus contingencies in pigeons

For three pigeons (Experiment 1), the presentation of a red response key ended with a food presentation either following two responses separated by at least 10 seconds (a DRL contingency) or following a 10-second response-free period (a DRO contingency). For three other birds (Experiment 2), a brief stimulus presentation terminated the DRL and DRO contingencies. A white side key was presented next and ended with response-dependent food following one contingency and a timeout following the other. Since the contingency on the red key was unsignaled, differential responding on the white side key could indicate that the two response-reinforcer relations had been discriminated. In Experiment 1, the red-key duration and number of responses influenced white-key responding following the contingency that predicted the timeout. A response-initiated DRO was instated, and the influence of red-key duration and response number on white-key responding was diminished. In both experiments, the 10-second time criterion in both contingencies was varied from 0.34 second to 10 seconds. Even at short time intervals the DRO and DRL contingencies were readily discriminated. Pigeons tended to class the two contingencies according to a rule that did not involve simply stimulus duration, numbers of responses, or even the time between a response and its consequence.