Skip to main content
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 3, 1990

Research Article

Reviews of Biology and Freedom, an Eassay on the Implications of Human Ethology

Reviewers -- Arthur L. Caplan, H.L. Kaye, Lisa Klopfer, and Peter Klopfer, Susan Oyama, and Stanley N. Salthe

Biology and Freedom: Reply to Reviewers

Biology and Freedom:  Reply to Reviewers

A Canadian Pioneer of Comparative Psychology: T. Wesley Mills (1847-1915)

A brief survey is given of the life and writings of T. Wesley Mills (1847-1915) with particular emphasis on his work on comparative psychology. He represented a position closer to Romanes than to Thorndike insofar as he felt that the intelligence of certain species of animals was often underestimated. He was also a pioneer in the keeping of diaries describing the development of sensory and cognitive abilities in the first days of life in puppies, kittens and the young of other species. He also tried to relate the development of these abilities to developments in the excitability of the cerebral cortex.

Odour Preferences and Discrimination in Captive Ringtail Possums ( Pseudocheirus peregrinus )

Olfactory communication has been shown to be important in marsupials and, specifically, in Trichosurus vulpecula and Petaurus breviceps . Despite its commonality, little is known about the communication in the ringtail possum, Pseudocheirus peregrines . Therefore, to investigate olfactory communication in the ringtail possum, two experiments were conducted. The odour preference experiment examined the importance of fur, salivary, faecal and urinary odours in ringtail possum olfactory communication. The latency to approach urinary odours was significantly longer than for any other odours. Males sniffed familiar female urine samples for a significantly shorter duration than any other odour samples. Fur samples were manipulated for longer durations than any other odour samples. The discrimination experiment examined the ability of ringtail possums to discriminate between urine samples, and hence obtain socially significant information from such odour sources. The ringtail possums showed that they were able to discriminate between individuals and between sexes. The possible functions of urine, fur and paracloacal gland secretions are discussed.

Primary Frustration in the Red Opossum ( Lutreolina crassicaudata )

Red opossums ( Lutreolina crassicaudata ) were trained in a Y-maze to locate a piece of food (the initial response, Ri) and afterwards to run back to the start box (the final response, Rf) where no reward was available immediately although a new trial was scheduled after a 30-s intertrial interval. Omission of food in some of the training sessions (Sessions 2, 10, 20, and 30) led to a decrement in latencies of the Rf, but only in Sessions 10 and 20, which was interpreted as evidence that primary frustration elicited by omission of an expected reward increases the vigor of ongoing instrumental behavior. The absence of this effect in the first and last extinction sessions ruled out an account based on post-ingestion factors, such as transitory satiation. The results are discussed in relation to vertebrate research on learning phenomena thought to depend on the frustrative consequences of nonreward.