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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 20, Issue 1, 2007


Influencing Science Policy through Effective Advocacy

There is an ongoing need for scientists to engage in advocacy efforts to protect the federal research infrastructure and funding sources for research. This article explains how researchers can join the American Psychological Association in advocating on behalf of psychological science.

Stubborn Facts Call for Stubborn Scientists

It is not only acceptable but desirable for scientists to speak out publicly in defense of science; moreover, given the current political environment, such actions are increasingly necessary. In the process, it is crucial that we remain open to rethinking our most cherished beliefs.

Crying in the Wilderness

Publish in high visibility journals. Acknowledge connection with comparative psychology. Stress positive features of comparative psychology rather than weaknesses of alternative approaches.

Should We Talk to the General Public about Our Work?

This essay regards the need of communication with the general public about our work. Our discussion focuses on a list of concerns, including who among us should be responsible for bringing our work to the public, what might be interesting to the public, what could be the best way to reach them and, finally, why this endeavor is so important. This discussion will also allow us to present our personal opinions and ideas about these concerns.

Comparative Psychology’s Relevance to a Liberal Arts Education and Personal Development

The purpose of a liberal arts education is to enhance critical thinking and to facilitate personal growth through knowledge and understanding of oneself and one’s relationship with the rest of the environment. Akin to this educational process is comparative psychology’s comprehensive perspective, characterized by concepts such as continuity , emergence and a Levels of Analysis approach to understanding. Comparative psychology is a model central to the purpose and value of a liberal arts education and, as such, has the potential to enhance that process and the consequent worth of our daily lives.

Encoding Structural Ambiguity in Rat Serial Pattern:The Role of Phrasing

Rats, like humans, appear sensitive to the structure of the elements of sequences. In the present study, we examined the effects of phrasing a structurally ambiguous pattern as either a series of “runs” or “trills.” A pattern phrased as runs was easier to learn than when it was phrased as trills, a result that resembles a similar “runs bias” reported in the human sequential learning literature. Whereas rats learning the runs-phrased pattern showed rapid learning and little tendency to make trills errors, rats learning the trills-phrased version of the pattern produced inflated rates of both trills and runs errors. The results show that rats represented the runs- and trills-phrased versions of the pattern differently. These results add to the evidence that, in addition to serving as discriminative cues, phrasing cues can bias pattern perception in rat serial pattern learning resulting in memorial representations characterized by multiple interpretations of the same pattern. The results also fit well with recent behavioral and neurobehavioral studies implicating multiple concurrent psychological and neural processes in rat serial pattern learning.

All Mothers are Not the Same: Maternal Styles in Bottlenose Dolphins (Tursiops truncatus)

A dolphin calf’s relationship with its mother is crucial for its survival and may be affected by the mother’s preferred mode of interacting with her calf. Mothers from a variety of species exhibit individual differences and stable maternal styles. However, little is known about individual differences in the maternal behaviors of dolphins. We investigated the possibility of maternal styles in dolphins by identifying specific maternal care behaviors in 7 dolphin mothers at two facilities during the first year of each calf’s life. The mothers exhibited different patterns of behavior including proximity maintenance, discipline, and initiation of separations and reunions with calves. These patterns of maternal behaviors suggest that dolphin mothers display a range of maternal styles that appear to be differentiated by level of maternal control. Moreover, a mother may also modify her individual style as her calf matures and as the social context changes.

A Species Difference in Visuospatial Working Memory:Does Language Link “What” with “Where”?

A computerized version of a popular children’s memory game (“Concentration”) was used to test the role of language in visuospatial working memory of humans, apes, and monkeys. Participants were required to find matching pairs of pictures by “flipping over” computer-generated cards, and to remember which images had been seen and where each was hidden. All participants were able to locate the pairs of stimuli, but the nonhuman animals were consistently and significantly worse than the human adults. When humans could not use language, performance declined. When the stimuli were meaningful symbols from the chimpanzees’ language keyboards, performance improved. These data suggest that language provides an important function even in visuospatial working memory, linking “memory for what” with “memory for where.”

Do Dolphins Eavesdrop on the Echolocation Signals of Conspecifics?

Preliminary experimental evidence shows that it is possible for an eavesdropping dolphin to discern object information from the returning echoes generated by the echolocation signals of conspecifics. Researchers have offered suggestions as to how this proposed ability may affect the behavior of wild dolphin species. A review of early and contemporary ideas, hypotheses and experiments concerning eavesdropping in dolphins is presented here, resulting in the development of a formalized, modern version of the ‘echoic eavesdropping’ hypothesis. The ecological implications of eavesdropping behavior remain unknown; refinement of the hypothesis and clarification of underlying assumptions are vital to our understanding of how echoic eavesdropping behavior might manifest itself in the social behavior of wild odontocetes. Suggestions for future research involving both echoic eavesdropping and a novel, alternative hypothesis (multi-source echoic eavesdropping) are offered. With the potential to elucidate many of the mysteries concerning dolphin biosonar use and dolphin behavior in general, echoic eavesdropping is an idea that deserves future attention.