Influence of timing of post-weaning isolation on play fighting and serious aggression in the male golden hamster (Mesocricetus auratus)

Effects of timing of social isolation on play fighting and serious fighting were studied at different ages in male golden hamsters. Litters were isolated at 21, 35, and 65 days of age, and tested in a resident-intruder paradigm. Behaviors were compared within grous and with a fourth group of socially reared conspecifics. The earlier the pups were isolated, the more they engaged in play activities. Later, in adulthood, the aggression level of the same animals was retested using the same paradigm. The three isolated groups showed a high level of aggression, with significant differences among them. When compared with socially reared subjects, a reliable difference in the level of aggression was also found. These results support the view that early social experience is important, suggesting that isolation during early critical periods of socialization has a significant impact on play fighting, whereas short periods of isolation may be enough to trigger adult agonistic behavior. © 1994 Wiley-Liss, Inc.     

Gains v. losses,or context dependence generated by confusion?

Animal Cognition - Tversky and Kahneman introduced the term framing for the finding that people give different answers to the same question depending on the way it is posed. One form of framing...     

Book reviews

Hall, G. (1991). Perceptual and associative leaning. Oxfod: Clarendon Press. Pp. xi + 300. ISBN 0-19-8524182-0. £35.00.

Rahmann, H., & Rahmann, M. (1992). The neurobilogical basis of memoy and behavior. New York: Springe Verlag. Pp. 292. ISBN 3-540-97545-4. £53.00.

Iversen, I.H., & Lattal, K.A. (Eds.). (1991). Experimental analysis of behavior, arts 1 and 2. Techniques in the behavioral and neural sciences, volume 6 (series editor: J.P Huston). Amstedam: Elsevier. Pp. 724. ISBN 0-444-8932-2. £50.00 (paperback).

Baudry, M., & Davis, J.L. (Eds.) (1991). Long-tem potentiation: A debate of current issues. Cambridge, Ma & London, England: MIT Press. Pp. xxii + 454. ISBN 0-262-02330-x. £62.95 (Hb).

The Biological Council Animal Reseach and Welfare Panel (1992). Guidelines on the handling and training of laboatory animals. Univer-sities Federation for Animal Welfare. Pp. ISBN 0-900767-77-4. £2.50.     

Parity still isn't a generalisation problem

Clark & Thornton take issue with my claim that parity is not a generalisation problem, and that nothing can be inferred about back-propagation in particular, or learning in general, from failures of parity generalisation. They advance arguments to support their contention that generalisation is a relevant issue. In this continuing commentary, I examine generalisation more closely in order to refute these arguments. Different learning algorithms will have different patterns of failure: back-propagation has no special status in this respect. This is not to deny that a particular algorithm might fortuitously happen to produce the "intended" function in an (oxymoronic) parity-generalisation task.     

Psychoanalysis and the Model of Homosexuality as Psychopathology: A Historical Overview

The American Journal of Psychoanalysis -     

A COMPARISON OF RUSSIAN AND U.S. PAY ALLOCATION DECISIONS, DISTRIBUTIVE JUSTICE JUDGMENTS, AND PRODUCTIVITY UNDER DIFFERENT PAYMENT CONDITIONS

This article reports the results of two studies of pay-related attitudes and behaviors of Russian and U.S. managers and students. In a pay allocation role play, managers in both countries place primary emphasis on individual performance (equity) and secondary emphasis on coworker relations and equality. In addition, Russian managerial subjects utilized need in their pay allocations. In a series of experiments, both Russian and U.S. students preferred the equity rule, although there were no productivity effects across different allocation rules. Procedural justice effects were also observed. Implications for pay practices are examined.     

Social feeding reverses learned flavor aversions in spotted hyenas (Crocuta crocuta).

Spotted hyenas are highly social carnivores with competitive feeding habits. It was hypothesized that social feeding might be capable of reversing an established flavor aversion. The dominant hyena of each of 4 captive social groups was given a novel food mixed with LiCl on Day 1; aversion to this food was demonstrated on Day 2. On Day 3, the dominant hyena and 3 or 4 members of her group were offered the food simultaneously. Three of the 4 dominant hyenas ate substantial quantities of the food during this group feeding, and all 4 hyenas ate the following day when offered the food alone. In contrast, when averted to a different novel food, the hyenas refused that food on 3 consecutive days. In this species social factors, such as those operating during group feeding, are sufficiently powerful to attenuate, immediately and dramatically, a strong LiCl-induced aversion.