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Open Access Publications from the University of California


The International Journal of Comparative Psychology is sponsored by the International Society for Comparative Psychology. It is a peer-reviewed open-access digital journal that publishes studies on the evolution and development of behavior in all animal species. It accepts research articles and reviews, letters and audiovisual submissions.

Volume 3, Issue 4, 1990

Research Article

Sameness-difference Judgments of Numerousness by Monkeys: Macaca mulatta and Macaca assamensis

Three of four monkeys were trained successfully on a series of number-related judgment problems ending with "same" and "different" judgments involving pairs of numerousness discriminanda. The discriminanda were black "dots" drawn on cards and constructed using controls to preclude the use of cumulative area or brightness cues and to make specific pattern memorization unlikely. On the final task, all possible same and different pairs of discriminanda representing the numbers 2 through 6 were used, and three monkeys met criterion (two successive sessions of 80% or more correct) in 80, 160, and 200 trials, respectively. Discussion considered possible underlying processes to explain the numerousness judgments as well as the implications of the present work for Piaget's views on conservation of quantity.

Avoidance of New Objects by the Black Rat (Rattus rattus) in Relation to Object Presentation and Object Change

This work compares object replacement and object presentation as causes of avoidance (new object reaction or neophobia). The movements of wild black rats, Rattus rattus, living in an automated plus maze were recorded (1) after replacing a familiar object (in a familiar place) with a series of novel objects, (2) after presenting a novel object in a familiar place where there had been no object. Replacing one object by another did not delay entry to the maze arm containing it. In contrast, the presence of a new object in a previously empty arm did increase the latency of the first approach (new object reaction), although after the first entry, the rate of visiting the arms and the time spent in them, which are measures of subsequent approach, were unaffected. Hence, this form of neophobic behavior was evoked only by the presence of a new object where none had been before. Differences with earlier reports can be resolved in most cases when attention is paid to the difference between presentation and replacement.

The Study of Animal Behaviour in India: Origin and Current Status

Recorded observations on animal behaviour in India date back to ancient times. Behaviour of various animals was observed and described in ancient Indian classics. Many species of animals have been described as 'Vahanas,' that is, animals ridden by various Hindu deities. The sculptures and drawings of a number of deities also include these mounts with their characteristic behavioural patterns. However, scientific investigations on animal behaviour is a recently developed branch of biological science in India, initiated in the late 1950's. Systematic ethological research on various species of Indian animals was begun only in early 1970's, after the formation of the Ethological Society of India. At present a variety of topics such as foraging and feeding behaviour, habitat selection, social and reproductive behaviour, chronobiology, chemical communication signals and neurobehaviour are being investigated by Indian ethologists, who are mainly zoologists, and a few psychologists. A wide range of species from lower metazoa to higher vertebrates are observed by ethologists in India. An analysis of the development of ethology in India indicates that the progress of this discipline as a major field of research and teaching in India is satisfactory. Further, if the present trend is maintained, ethology should develop as a major discipline of animal research in India by the year 2000.

Acknowledgement of Reviewers

We wish to thank the following colleagues who reviewed manuscripts submitted for Volumes 1 and 3