Counting behavior in animals: A critical evaluation.

Abstract

In this article we present a critical evaluation of evidence bearing on the question of whether animals can count. A definition of counting is adopted from Gelman and Gallistel (1978) and Piaget (1952) that allows us to compare the form of counting behavior observed in animals with its counterpart in humans. The evidence, which ranges from early anecdotal reports to modern experimental analyses, suggests that a variety of infrahumans ranging from birds to primates can learn to count, although successful demonstrations are most likely to occur under relatively extreme experimental conditions when alternative predictors of food or safety are unavailable. Counting behavior appears to be a relatively unnatural response in infrahumans, and its acquisition may reflect the boundaries of the animal's associative abilities. This paper will present a critical evaluation of some of the evidence that has been brought to bear on the question of whether animals can count. Perhaps a better title would have been "Counting Behavior in Animals: When Does It Occur?" for we intend to argue that counting behavior, as we will define it, can and does occur in infrahuman animals. In taking this position, we will avoid the euphemism countinglikebehavior, which has been used to describe much of the experimental work of the past 20 years.Counting Behavior Denned Some definitions of counting behavior preclude the possibility that animals can count. In contrast, it is possible to define counting in a way that is not only consistent with its occurrence in humans but also allows for its demonstration in other species. We will attempt to evolve such a definition.

Some further observations on serial enumeration and categorical flexibility

“…This viewof the rat's countingcontrasts sharply with an earlier view proposed by Davis and Memmott (1982), who concluded that natural history has giventhe rat little reason to count, especially in "unnatural" settings.…”

When quantity trumps number: discrimination experiments in cotton-top tamarins (Saguinus oedipus) and common marmosets (Callithrix jacchus)

“…Some researchers have argued that using number may be a "last-resort" strategy of quantification (Breukelaar and Dalrymple-Alford 1998; Davis and Memmott 1982) when other cues such as amount cannot be used (but see Brannon 2005a). These mechanisms of quantification have presumably evolved to enhance survival and successful reproduction of individuals in their natural environment, such as in foraging, inter-group conflict, parental investment, and predator avoidance contexts (Hamilton 1971;Kitchen 2004;Lyon 2003;McComb et al 1994;Wilson et al 2001).…”

Numerical competence in a chimpanzee (Pan troglodytes).

“…Counting, however, like other cognitive behaviors such as language, has often been defined to exclude nonhuman numerical competence (Davis & Memmott, 1982). The revitalization of studies of animal cognition has provided an emerging theoretical framework for examining the phylogenetic continuum of information processing (Hulse, Fowler, & Honig, 1978;Roitblat, Bever, & Terrace, 1984).…”