Bennett G. Galef

The question of animal culture

In this paper I consider whether traditional behaviors of animals, like traditions of humans, are transmitted by imitation learning. Review of the literature on problem solving by captive primates, and detailed consideration of two widely cited instances of purported learning by imitation and of culture in free-living primates (sweet-potato washing by Japanese macaques and termite fishing by chimpanzees), suggests that nonhuman primates do not learn to solve problems by imitation. It may, therefore, be misleading to treat animal traditions and human culture as homologous (rather than analogous) and to refer to animal traditions as cultural.

Biological constraints on instrumental and classical conditioning: retrospect and prospect

The adequacy of traditional approaches to the study of animal learning to account fully for learning phenomena has been seriously questioned during the past decade. Critics of traditional analyses advocated a biological orientation to the interpretation of associative processes and introduced a variety of concepts intended to provide a new framework for the study of animal learning. This promise of a reorientation of the field has not been realized. The concepts of biological constraints, adaptive specializations, and situation specificity of learning have had a less profound influence on the general process approach to instrumental and classical conditioning than anticipated. The present paper makes explicit the conceptual bases of the original biological approaches to learning, identifies reasons why they failed to change fundamentally the study of instrumental and classical conditioning, and proposes an alternative approach to the use of ecological and evolutionary principles in studies of conditioning. We suggest a renewed comparative approach to the study of learning phenomena that avoids many of the difficulties inherent in earlier formulations by providing (1) a strategy for the discovery of adaptive specializations in learning, (2) an ecological framework for the discussion of these adaptive specializations, and (3) a renewed emphasis on the study of species differences in learning.

Carbon disulfide: a semiochemical mediating socially-induced diet choice in rats.

Gas chromatography/mass spectrometry revealed the presence of both carbon disulfide (CS2) and carbonyl sulfide (COS) on rat breath. Behavioral experiments indicated that rats exposed to an unfamiliar diet moistened with CS2, like rats exposed to an unfamiliar diet placed on the fur of an anesthetized rat, subsequently exhibited enhanced preference for the unfamiliar diet. Rats in experimental groups: (a) interacted for 30 min with a wad of cotton batting powdered with one of two unfamiliar foods (either Diet A or Diet B) and moistened with a dilute, aqueous CS2 solution, (b) ate Diets A and B in succession and finally, (c) were injected with LiCl. In a subsequent choice between Diets A and B, these rats exhibited a preference for whichever of the foods had been present on the cotton batting during (a). Rats in control groups were treated identically to those in experimental groups, except that the diet-coated cotton batting to which they were exposed was moistened with distilled water rather then CS2 solution. Rats in control groups were not affected in their later diet choice by the food present on the cotton batting during (a). These data are consistent with the hypothesis that CS2 is a semiochemical that mediates social influence on diet selection in rats.

Prenatal influences on reproductive life history strategies

Over the past two decades, evolutionary and behavioural ecologists have become increasingly interested in the adaptive consequences of intraspecific variability in life history and behavioural strategies. Recently, behavioural endocrinologists have begun to uncover surprising relationships between levels of prenatal exposure to gonadal hormones and variation in reproductive behaviour in adulthood. Such relationships may provide a causal explanation for many variations in adult phenotype that are of insterest to behavioural and evolutionary ecologists.

Demonstrator influence on observer diet preference: Analyses of critical social interactions and olfactory signals

Previous studies have shown that interaction of an observer rat with a previously fed conspecific demonstrator enhances the observer’s subsequent preference for the diet its demonstrator ate. The present series of experiments were undertaken to explore both the conditions sufficient to permit demonstrator influence on observer diet preference and the behavioral processes underlying such influence. We found (1) that an observer rat can be influenced in its subsequent diet selection by interaction for as little as 2 min with a demonstrator, (2) that during such brief interactions mouth-to-mouth contact between demonstrator and observer is necessary for demonstrator influence on observer diet preference, (3) that both cues emerging from the digestive tract of a rat fed by intragastric intubation and particles of food clinging to the fur of a demonstrator are sufficient to permit observers to identify their respective demonstrators’ diets, (4) that exposure to a diet is effective in enhancing an observer’s subsequent preference for that diet only if the diet is experienced in the presence of another rat, and (5) that diets experienced on the anterior of a live rat are more effective in altering observers’ subsequent diet preferences than the same diets experienced either on the anterior of a dead rat or the posterior of a live one.

Why behaviour patterns that animals learn socially are locally adaptive

Recent models of the social transmission of behaviour by animals have repeatedly led their authors to the counterintuitive (and counterfactual) conclusion that traditional behaviour patterns in animals are often not locally adaptive. This deduction results from the assumption in such models that frequency of expression of socially learned behaviour patterns is not affected by rewards or punishments contingent upon their expression. An alternative approach to analysis of social learning processes, based on Staddon–Simmelhag’s conditioning model, is proposed here. It is assumed that social interactions affect the probability of introduction of novel behaviour patterns into a naive individual’s repertoire and that consequences of engaging in a socially learned behaviour determine whether that behaviour continues to be expressed. Review of several recently analysed instances of animal social learning suggests that distinguishing processes that introduce behaviour patterns into the repertoires of individuals from processes that select among behavioural alternatives aids in understanding observed differences in the longevity of various traditional behaviour patterns studied in both laboratory and field. Finally, implications of the present approach for understanding the role of social learning in evolutionary process are discussed. During their lifetimes, individual animals can acquire behaviour in one of two ways: by individual learning or by social learning. Individual learning refers to behaviour acquired by an animal as the result of its own experience of the rewards and punishments contingent upon engaging in various acts, while social learning refers to those instances in which the acquisition of behaviour is influenced by observation of or interaction with another animal or its products (Heyes 1994). Classic examples of socially learned behaviour include the song dialects of white-crowned sparrows, Zonotrichia leucophrys (Marler 1970), sweet-potato washing and wheat placer mining exhibited by macaques on Koshima Island in Japan (Kawamura 1959) and the termite fishing engaged in by chimpanzees in Gombe National Park, Tanzania (Goodall 1973). The numerous behavioural processes supporting social learning in animals have been discussed at length elsewhere (Galef 1988; Whiten & Ham 1992; Heyes 1994) and will not be considered further here. Both individual and social learning are forms of phenotypic plasticity enabling animals to acquire behaviour that is adaptive in local habitat (Boyd & Richerson 1988). Theoreticians have argued that individual learning and social learning have different patterns of costs and benefits that make one or the other superior in any given environment. For example, Rogers (1988) discussed a hypothetical species, the ‘snerdwump’, whose members inhabit a variable environment and learn what foods to eat either by individual learning (sampling among available foods and discovering which is the most nutritionally valuable) or by copying the food choices of a member of the previous generation. In environments that are relatively constant across generations, snerdwumps that avoided exposure to poisons by copying the food choices of their elders would prosper, while snerdwumps that lived in environments that fluctuated significantly between generations and learned what to eat by copying members of the previous generation would be unable to discover superior foods that their brethren might identify while learning what to eat by trial and error. Psychologists studying behavioural traditions in animals have generally assumed that no learned behaviour, whether acquired socially or individually, will be long maintained in an individual’s repertoire unless that behaviour is at least as likely to produce rewards as are available alternatives (Galef 1976; Heyes 1993). Furthermore, most students of social learning have assumed implicitly 0003–3472/95/051325+10

The role of the physical rearing environment in the domestication of the mongolian gerbil (Meriones unguiculatus)

08.00/0 ? 1995 The Association for the Study of Animal Behaviour

'culture' in quail : social influences on mate choices of female Coturnix japonica

Gerbils reared in tunnel systems responded to a visual stimulus by fleeing, foot-thumping and remaining concealed, whereas many gerbils reared in laboratory cages responded in the same situation by approaching the stimulus. The critical factor in tunnel-rearing was the opportunity to flee to shelter during maturation. Neither isolation from illumination nor isolation from stimuli associated with human handlers produced the observed effect. Gerbils reared in laboratory cages exhibit the pattern of flight and concealment in response to stimulation following 24-hr experience in a tunnel system. The data are discussed in terms of their implications for models of the ontogeny of the behaviour characteristic of domesticated, as compared with wild, strains.

Female Japanese quail that ‘eavesdrop’ on fighting males prefer losers to winners

We have shown previously that after a focal female Japanese quail, Coturnix japonica, sees a conspecific male mating, the focal females tendency to affiliate and to mate with that male is significantly increased. Here we describe two experiments demonstrating that a focal female quail that has seen a conspecific male mating subsequently shows an enhanced tendency to affiliate not only with that particular male, but also with other males that share his characteristics. The results have important implications for our understanding of the role of social learning in the evolution of male characteristics. Copyright 2000 The Association for the Study of Animal Behaviour.

Demonstrator influence on observer diet preference: Effects of simple exposure and the presence of a demonstrator

In a series of four experiments, we examined the relationship between male dominance and female preference in Japanese quail, Coturnix japonica. Female quail that had watched an aggressive interaction between a pair of males preferred the loser of an encounter to its winner. This superficially perverse female preference for losers may be explained by the strong correlation between the success of a male in aggressive interactions with other males and the frequency with which he engages in courtship behaviours that appear potentially injurious to females. By choosing to affiliate with less dominant male quail, female quail may lose direct and indirect benefits that would accrue from pairing with dominant males. However, they also avoid the cost of interacting with potentially harmful, more aggressive males.