ABSTRACT
Comparative psychology is conventionally viewed as the study of behavior in different spe cies of nonhuman animals. One of the dominant aims of comparative psychology has been to identify similarities in basic behavioral pro cesses in different species, and to attribute the source of behavioral similarities either to adap tation to common exigencies in the environment (often referred to as analogy or convergence) or to shared evolutionary heritage (referred to as homology) (Ridley, 1983). These aims are well illustrated by comparative studies of learning. Modern studies of animal learning have often emphasized the need to view the animal in an appropriate environmental context. One species may exhibit remarkable learning capacities in one domain (such as storage and recall of the places food is stored) while it exhibits mediocre performance in other learning tasks (such as maze learning). Early conclusions about the lim ited learning abilities and intelligence of animals have been replaced by the recognition that learning capacities are strongly influenced by the ecological demands faced by different spe cies. This recognition has provided both a strength and a caveat for comparative analysis in general, since it forces researchers to tailor the protocols used to evaluate learning abilities to the sensory capacities and ecological needs of the species under scrutiny, which in turn com plicates the broader goal of identifying general principles that may apply to questions of learn ing across widely disparate groups of animals.
