Human–Grey Parrot Comparisons in Cognitive Performance

Abstract

Prior to Darwin, humans lived in a different world from other species. While our machines were inhabited by ghosts, other creatures were simply machines devoid of internal states (Descartes, 1641). With the publication of the Origin of Species in 1859, however, people began to question this anthropocentric assumption of a discontinuity between “us” and “them.” Thirteen years later in Darwin’s final book, The Expression of the Emotions in Man and Animals (1872), he developed this argument of continuity between human and nonhuman species further by drawing on observations of parallels of expression and reaction in a wide range of species. It is fair to say that The Expression of the Emotions led directly to the development of “comparative psychology” and provided legitimacy to the study of animal behavior as a means to better understand ourselves (Workman, 2013). In 1894, Conway Lloyd Morgan formalized this approach in his book, Introduction to Comparative Psychology, setting out the ground rules for the comparative method. During the twentieth century, comparative psychology subdivided into two main approaches. One approach focused on the internal states of animals and eventually developed into the new field of animal cognition, while the other attempted to exorcise mentalistic language from the field of animal behavior and eventually became known as behaviorism. Today, studies of animal cognition still draw on Darwin’s conception of continuity between species, but, by integrating developments in ethology and neuroscience, they also relate specific cognitive abilities to the behavioral ecology of a population. It is fair to say that Irene M. Pepperberg’s research into avian cognition is a major contribution to the field of animal cognition. Pepperberg’s work with African Grey parrots showed how a species that has not shared a common ancestor with our own lineage since the late Carboniferous period can nonetheless exhibit human-like vocal communication. We begin Part I with her chapter on human–Grey parrot comparisons in cognitive performance. The old adage that “elephants never forget” is based on a large body of anecdotal evidence. In recent years, however, field and lab studies have begun to put some flesh on these anecdotal bones. Lucy Bates has spent a number of years observing and testing this social giant. Her chapter on the cognitive abilities in elephants reinforces and dispels the myths that have built up around the intellectual prowess of these largest of all land animals. Another group of animals that, due to their apparent complex social behavior, has long fascinated us is the cetaceans. Like elephants, whales and dolphins are renowned for their apparent cognitive prowess. In the third and final chapter in Part I, Ellen C. Garland and Luke Rendell consider culture and communication among cetaceans. Is it possible that we can improve our understanding of the roots of human language and culture by studying creatures that evolved in the three-dimensional liquid world of the oceans? Garland and Rendell provide us with the current state of play with regard to these questions and suggest fertile areas for future research.