CAN IMITATION IN PIGEONS BE EXPLAINED BY LOCAL ENHANCEMENT TOGETHER WITH TRIAL-AND-ERROR LEARNING?

Abstract— Zentall Sultan and Sherburne (1996) reported that pigeons observing a conspecific demonstrator either step on or peck at a treadle to obtain food subsequently showed a significant tendency to manipulate the treadle as had their demonstrator. Zentall et al suggested this finding showed observer pigeons had learned by imitation to peck at or step on the treadle. However, the same result might have been obtained of pigeons had learned to step on the treadle by trial and error, and pigeons exposed to a treadle-pecking demonstrator had come to peck at the treadle as a result of nonimitative social learning processes such as local enhancement or contagion. Here we report the results for two control groups showing that pigeons do not learn to step on or peck at a treadle for food reward unless they observe a relevant demonstrator. These results considerably strengthen the original conclusion. Future research using the two action method to demonstrate imitative learning should include similar controls.     

Marks and classroom adjustment as early indicators of mental health at age twenty

The data are derived from a 15-year longitudinal study of 659 urban children who entered kindergarten in 1968, 371 who were interviewed at the age of 20. Analyses related school adjustment and academic performance in the early primary grades, early adolescence, and middle adolescence to mental health outcomes based on responses to a short form of the MMPI at age 20. The results suggest that poor marks, absence of positive coping behaviors, and presence of negative coping behaviors are indicators of later mental health problems, that the absence of positive coping behaviors may be more indicative of later problems than the presence of negative coping behaviors, and that there are sex differences in the time periods at which indicators of school productivity are important.     

An index of factorial simplicity

An index of factorial simplicity, employing the quartimax transformational criteria of Carroll, Wrigley and Neuhaus, and Saunders, is developed. This index is both for each row separately and for a factor pattern matrix as a whole. The index varies between zero and one. The problem of calibrating the index is discussed.The research reported in this paper was supported in part by the Office of Computing Activities, National Science Foundation.     

Individual differences in the detection of embedded figures

The individual differences in processing obtained by Hock (1973) were extended to two experiments in which the embedded figures test was recast into the form of a yes-no reaction time task. Ss emphasizing analytic processes detected the embedded figures more rapidly than Ss emphasizing structural processes, supporting the hypothesis that attention to the parts of the embedded figures was the strategy most appropriate for the task. Based on the interaction between familiarity (normal vs rotated orientation) and embeddedness (intact vs embedded figures), it was concluded in both experiments that familiarity facilitated the detection of the embedded figures for analytic Ss. For structural Ss, familiarity was similarly found to facilitate the detection of the embedded figures, but only when a template-matching strategy was possible (when the target figure and the embedded figure were physically identical).     

The Conciliator in College Counseling

The conciliative techniques for assisting in the management of dissonance conditions are suggested for counseling the troubled student. Ecologically induced problems are cited for the typical student Conciliative modes are then proposed as ways of construing the counseling relationship. Thus, conciliating means reinforcing desires for relief, assisting in more carefully discriminated definitions, creating a sense of sharing in the counselee, and modifying crucial self-images. The conciliator is identified as the counselor who interacts with the motive-dissonant student in promoting more peaceful interpretations of frustration and intra-personal conflict.     

The varimax criterion for analytic rotation in factor analysis

An analytic criterion for rotation is defined. The scientific advantage of analytic criteria over subjective (graphical) rotational procedures is discussed. Carroll's criterion and the quartimax criterion are briefly reviewed; the varimax criterion is outlined in detail and contrasted both logically and numerically with the quartimax criterion. It is shown that thenormal varimax solution probably coincides closely to the application of the principle of simple structure. However, it is proposed that the ultimate criterion of a rotational procedure is factorial invariance, not simple structure—although the two notions appear to be highly related. The normal varimax criterion is shown to be a two-dimensional generalization of the classic Spearman case, i.e., it shows perfect factorial invariance for two pure clusters. An example is given of the invariance of a normal varimax solution for more than two factors. The oblique normal varimax criterion is stated. A computational outline for the orthogonal normal varimax is appended.Part of the material in this paper is from the writer's Ph.D. thesis. I am indebted to my committee, Professors F. T. Tyler, R. C. Tryon, and H. D. Carter, chairman, for many helpful suggestions and criticisms. Dr. John Caffrey suggested the namevarimax, and wrote the original IBM 602A computer program for this criterion.I am also indebted to the staff of the University of California Computer Center for help in programming the procedures described in the paper for their IBM 701 electronic computer. Since their installation is partially supported by a grant from the National Science Foundation, the assistance of this agency is acknowledged.     

The effects of electroconvulsive shock on the action of a reinforcing stimulus

Three experiments sought to evaluate the effect of electroconvulsive shock on the action of a reinforcing stimulus. In all experiments behavior was maintained on a 2 min variable interval schedule for food reinforcement. Foot shock at the termination of a buzzer stimulus served as the reinforcing stimulus for conditioned suppression during the ensuing buzzer interval. Omission of foot shock at the termination of the buzzer stimulus was followed by normal responding (no conditioned suppression) during the next buzzer interval. In Exp I electroconvulsive shock followed foot shock at varying time intervals. In the first subsidiary experiment electroconvulsive shock followed an unreinforced buzzer stimulus at varying time intervals. In the second subsidiary experiment electroconvulsive shock followed foot shock at varying time intervals and an additional buzzer stimulus was sounded between the termination of foot shock and the onset of electroconvulsive shock. These three experiments demonstrated that electroconvulsive shock invariably abolished the effects of the reinforcing stimulus if it followed conditioning by no more than 10.0 sec and never had an effect if it followed conditioning by 12.5 sec or more; electroconvulsive shock was not acting as a reinforcing stimulus in this situation.     

Type A behavior pattern, inhibited power motivation, and activity inhibition

The constructs of the Type A behavior pattern and the Inhibited Power Motive Syndrome (IPMS) have many features in common. The empirical relation between the two constructs was investigated in this study with 45 employed, male medical and surgical patients. Four different measures of the Type A pattern were examined. Results showed that, of the four measures, the Structured Interview and the Hostility Scale were related significantly to the IPMS. Systolic blood pressure reactivity was also related significantly to the IPMS. These relations could be ascribed largely to activity inhibition alone. The contribution of activity inhibition to an understanding of the biological and psychological substrates of the Type A behavior pattern is discussed.