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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 10, Issue 4, 1997


Consistency of Skinner Box Activity Measures in the Domestic Rabbit (Oryctolagus Cuniculus)

Consistency of

individual differences in several measures of Skinner box operant and other activity and their intercorrelations in 14 chinchilla bred rabbits were studied. Reliability analysis revealed that both operant and activity measures were highly consistent (Cronbach alpha>0.87) over at least 15 days. Furthermore, locomotor activity, the tendencies to press the lever with high frequency, to make many errors, to check the presence of food in the dispenser as well as rearing were highly intercorrelated, making up a single dimension of activity. However, grooming did not correlate with these behaviors.

Observing Behavioral Qualities


movements have distinctive qualities, and these qualities can vary even when the form of the movement remains relatively constant. Description of behavioral qualities by trained observers can be useful in basic behavioral research and in applications ranging from behavioral ecology to clinical medicine. A method called Laban movement analysis differentiates four separate bipolar effort factors that contribute to the quality of body movement. Using independent rankings of videotaped behavioral sequences,we verified that observers can distinguish behavioral qualities liably when using the Laban system. Observers generally agreed both on the kind(s) of effort factor(s) present and on the mode or degree of expression of each factor. We discuss the potential and limitations of the Laban system as applied to animal behavior and identify some philosophical issues that arise from attempts to link the study of behavioral quality to the study of form and space, and to a possible emerging "science of qualities". 


Evolutionary Psychology, Adaptation, and the Evoltion of Lanaguage: Is there a Need for Comparsion?

A general assumption held by evolutionary psychologists is that a reference point for examining the origins and evolution of human psychological adaptations exists within a time range beginning roughly two million years ago. Scenarios for explaining the evolution of human psychological processes often allude to possible election pressures encountered by hominids during this time. unfortunately, comparative psychology and ethology are relatively absent from much current evolutionary psychological thought. Selective pressures that existed during the putative environment of evolutionary adaptedness may have predated the origin of hominids. Based on examples of the evolution of communication, this paper offers another approach to discovering the origins and evolution of psychological traits, with the aim of modifying a potentially misleading assumption of evolutionary psychology.