Development of Piagetian object permanence in grey parrot (Psittacus erithacus).

Abstract

The authors evaluated the ontogenetic performance of a grey parrot (Psittacus erithacus) on object permanence tasks designed for human infants. Testing began when the bird was 8 weeks old, prior to fledging and weaning. Because adult grey parrots understand complex invisible displacements (I. M. Pepperberg & F. A. Kozak, 1986), the authors continued weekly testing until the current subject completed all of I. C. Uzgiris and J. Hunt's (1975) Scale 1 tasks. Stage 6 object permanence with respect to these tasks emerged at 22 weeks, after the bird had fledged but before it was completely weaned. Although the parrot progressed more rapidly overall than other species that have been tested ontogenetically, the subject similarly exhibited a behavioral plateau part way through the study. Additional tests, administered at 8 and 12 months as well as to an adult grey parrot, demonstrated, respectively, that these birds have some representation of a hidden object and understand advanced invisible displacements.

Do Dogs (Canis familiaris) Understand Invisible Displacement?

“…However, striking exceptions to this pattern of findings have come from research with dogs (e.g., Gagnon & Doré, 1992, 1993, 1994Triana & Pasnak, 1981) and psittacine birds (e.g., Pepperberg & Funk, 1990;Pepperberg & Kozak, 1986;Pepperberg, Willner, & Gravitz, 1997). In two longitudinal studies, puppies (Gagnon & Doré, 1994) and an African grey parrot (Pepperberg et al, 1997) were shown to progress through a sequence of stages on displacement tasks similar to those of human infants. Piaget's (1937Piaget's ( /1954 classic task has been modified to varying degrees in order to suit the sensory and motor characteristics of nonhuman species.…”

“…In contrast, testing across a wide range of species has failed to reveal consistent evidence of success on the task in most other animals, including dolphins (Doré, Goulet, & Herman, 1991), numerous species of monkeys (e.g., de Blois et al, 1998;Natale & Antinucci, 1989), cats (e.g., Doré, 1986;Dumas, 1992), hamsters (Thinus-Blanc & Scardigli, 1981), and domestic chickens (É tienne, 1973). However, striking exceptions to this pattern of findings have come from research with dogs (e.g., Gagnon & Doré, 1992, 1993, 1994Triana & Pasnak, 1981) and psittacine birds (e.g., Pepperberg & Funk, 1990;Pepperberg & Kozak, 1986;Pepperberg, Willner, & Gravitz, 1997). In two longitudinal studies, puppies (Gagnon & Doré, 1994) and an African grey parrot (Pepperberg et al, 1997) were shown to progress through a sequence of stages on displacement tasks similar to those of human infants.…”

“…The possibility of a "Clever Hans" effect was not explicitly addressed in most previous invisible displacement studies with animals. Even when sunglasses or baseball caps have been worn by experimenters to avoid giving eye-gaze cues (e.g., Call, 2001;de Blois et al, 1998;Pepperberg et al, 1997), subtle body movements may have affected subjects' performance. Dogs have shown considerable skill in the area of social cognition, outperforming apes in their ability to respond appropriately to a variety of human cues communicating the location of food (Hare, Brown, Williamson, & Tomasello, 2002).…”

Dog-logic: inferential reasoning in a two-way choice task and its restricted use

“…Previous studies with several species showed that some primates (e.g. orang-utans, Pongo pygmaeus: de Blois et al 1998;orang-utans: Call 2001;chimpanzees, Pan troglodytes: Wood et al 1980;cottontop tamarins, Saguinus oedipus: Neiworth et al 2003), magpies, Pica pica (Pollok et al 2000), grey parrots, Psittacus erithacus (Pepperberg et al 1997) and dogs, Canis familiaris (Gagnon & Doré 1992, 1993 were able to solve the single invisible displacement tasks. However, it is doubtful whether dogs really used inferential reasoning to find the reward or whether they solve the problem by using local rules (Watson et al 2001;Collier-Baker et al 2004.…”

Domesticated dogs' (Canis familiaris) use of the solidity principle

“…Studies have also begun to reveal how other species represent objects (e.g., Pepperberg and Kozak 1986;Goulet et al 1994;Funk 1996;Pepperberg et al 1997;Pollock et al 2000;Cooper et al 2003;Fiset et al 2003Collier-Baker et al 2004;Mendes and Huber 2004;Fiset and Doré 2006;Zucca et al 2007;Miklósi 2007;Miller et al 2009;Whitt et al 2009;Deppe et al 2009). Indeed, such explorations could provide new insights into tasks with human and non-human primate populations.…”