Animal cognition

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Animal cognition, or cognitive ethology, is the title given to a modern approach to the mental capacities of animals. It has developed out of comparative psychology, but has also been strongly influenced by the approach of ethology, behavioral ecology, and evolutionary psychology. Much of what used to be considered under the title of animal intelligence is now thought of under this heading. Animal language acquisition, attempting to discern or understand the degree to which animal cognistics can be revealed by linguistics-related study, has been controversial among cognitive linguists.

Note that the term "animal" is used here and in the following in the usual sense of "non-human animal", even though its meaning in biology normally comprises all members of the kingdom Animalia, including humans.

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[edit] Historical background

For most of the twentieth century, the dominant approach to animal psychology was to use experiments on intelligence in animals to uncover simple processes (such as classical conditioning and operant conditioning) that might then account for the apparently more complex intellectual abilities of humans. This reductionist philosophy was combined with a strongly behaviorist methodology, in which overt behavior was taken as the only valid data for the study of psychology, and in its more extreme forms (the radical behaviorism of B. F. Skinner and his experimental analysis of behavior) behavior was taken as the only topic of interest. In effect, the mental processes that humans experience in themselves were viewed as epiphenomena.

The success of cognitive psychology in addressing human mental processes, from the late 1950s on, led to a re-evaluation of the research paradigm, and researchers began to address animal mental processes from the opposite direction, by taking what is known about human mental processes and looking for evidence of comparable processes in other species. In a sense this was a return to the approach of Darwin's protegé George Romanes, arguably the first comparative psychologist of the modern era. However, whereas Romanes relied heavily on anecdote and an anthropomorphic projection of human capacities onto other species, modern researchers in animal cognition are in most cases firmly behaviorist in methodology, even though they differ sharply from the behaviorist philosophy. There are some exceptions to the rule of behaviorist methodology, such as John Lilly and, some would argue, Donald Griffin, who have been prepared to take a strong position that other animals do have minds and that human's should approach the study of their cognition accordingly. However, their claims have not found wide acceptance in the scientific community, though they have attracted an enthusiastic following among lay people.

The development of animal cognition was also strongly influenced by:

This account of the history of the study of animal cognition is inevitably oversimplified. From Romanes on, there have always been comparative psychologists who have been more or less cognitively inclined: obvious examples are Wolfgang Köhler, famous for his studies of insight in chimpanzees, and Edward C. Tolman, who introduced into psychology, as an explanation of the behavior of rats in mazes, two ideas that have been immensely influential in human cognitive psychology - the cognitive map and the idea of decision-making in risky choice according to expected value.

[edit] Methodology

Research in animal cognition continues to use some of the established research techniques of comparative psychology and the experimental analysis of behavior, such as mazes and Skinner boxes, though it employs them in new varieties (such as the 8-arm maze and water maze that have been used in many studies of spatial memory) and in new ways. However, it complements those with observation of animals in their natural environments, or quasi-natural environments and also with field experiments. It has also been characterised by a number of very long term projects, such as the Washoe project and other ape-language experiments (e.g. project Nim), Irene Pepperberg's extended series of studies with the African Gray Parrot Alex, Louis Herman's work with bottlenosed dolphins, and studies of long-term memory in pigeons in which birds were shown to remember pictures for periods of several years. Some cognitive research also requires the management of animal behavior, and the use of operant conditioning to facilitate animal training. In general, the conclusion of concept formation in an animal requires a generalization test where the animal responds appropriately to a novel stimulus to which associative learning cannot explain the response behavior. Some researchers have made effective use of a Piagetian methodology, taking tasks which human children are known to master at different stages of development, and investigating which of them can be performed by particular species. Others have been inspired by concerns for animal welfare and the management of domestic species: for example Temple Grandin has harnessed her unique expertise in animal welfare and the ethical treatment of farm livestock to highlight underlying similarities between humans and other animals.

[edit] Research questions

Given the broad program of animal cognition, of looking for the animal analogs of human cognitive processes, the areas of study in animal cognition follow more or less from those in human cognitive psychology. However progress in the different areas has been variable. Among the fields of interest are:

[edit] Attention

Research has focused on animals' ability to distribute attention between different aspects of a stimulus, and on visual search. As in humans, it appears that sharing attention between stimulus features reduces the capacity to detect any one of them, though there are some ecologically relevant visual search tasks at which particular species show remarkable abilities (for example, pigeons have an extraordinary capacity to pick out grain from substrate).

[edit] Categorization

Following pioneering research by Richard Herrnstein, there has been a mass of research on birds' ability to discriminate between categories of stimuli, including the kinds of ill-defined category that are used in everyday human speech. Birds have been found to learn this kind of task easily, and to transfer correct responses readily to new instances of the categories.

[edit] Memory

The categories that have been developed to analyse human memory (short term memory, long term memory, working memory) have been applied to the study of animal memory, and some of the phenomena characteristic of human short term memory (e.g. the serial position effect) have been detected in animals particularly monkeys. However most progress has been made in the analysis of spatial memory, partly in relation to studies of the physiological basis of spatial memory and the role of the hippocampus, and partly in relation to scatter-hoarding animals such as Clark's Nutcracker, certain jays, titmice and certain squirrels, whose ecological niches require them to remember the locations of thousands of caches, often following radical changes in the environment.

[edit] Tool and weapon use

There are some species that use particular tools as an essential part of their foraging behavior, for example the Woodpecker Finch of the Galapagos Islands. However these behaviors are often quite inflexible and cannot be applied effectively in new situations. Several species have now been shown to be capable of more flexible tool use. A well known example is Jane Goodall's observation of chimpanzees "fishing" for termites in their natural environment, and captive great apes are often observed to use tools effectively; several species of corvids have also been trained to use tools in controlled experiments, or use bread crumbs for bait-fishing [1].

Research in 2007 shows that chimpanzees in the Fongoli savannah sharpen sticks to use as spears when hunting, considered the first evidence of systematic use of weapons in a species other than humans.[1][2]

[edit] Reasoning and problem solving

Closely related to tool use is the study of reasoning and problem solving. Many of the data on these issues come from earlier comparative psychologists such as Wolfgang Köhler, rather than recent experiments. It is clear that animals of quite a range of species are capable of solving a range of problems that are argued to involve abstract reasoning; modern research has tended to show that the performances of Köhler's chimpanzees, who could achieve spontaneous solutions to problems without training, were by no means unique to that species, and that apparently similar behavior can be found in animals usually thought of as much less intelligent, if appropriate training is given.

[edit] Language

The modeling of human language in animals is known as animal language research. In addition to the ape-language experiments mentioned above, there have also been more or less successful attempts to teach language or language-like behaviour to some non-primate species, including the parrot Alex, and Great Spotted Woodpeckers. Louis Herman published research on artificial language comprehension in the bottlenosed dolphin using cognitive research methods at the height of the skepticism produced by Herbert Terrace's criticism of chimpanzee language experiments through his own results with the animal Nim Chimpsky. In particular, the focus on the comprehension mode only allowed cognitive methods of utilizing blinded observers to grade the animals' gross physical behavior, rather than trying to interpret putative language production. Herman's results (Herman, Richards, & Wolz, 1984) were published in the (human) journal Cognition, regarding work on the dolphins Akeakamai and Phoenix.

[edit] Consciousness

The sense in which animals can be said to have consciousness or a self-concept has been hotly debated; it is often referred to as the debate over animal minds. The best known research technique in this area is the mirror test devised by Gordon Gallup, in which an animal's skin is marked in some way while it is asleep or sedated, and it is then allowed to see its reflection in a mirror; if the animal spontaneously directs grooming behaviour towards the mark, that is taken as an indication that it is aware of itself. Self-awareness, by this criterion, has been reported for chimpanzees and also for some other great apes, some cetaceans and a solitary elephant, but not for monkeys. However both the interpretation of such data, and the data themselves, remain controversial, as it would seem to test the ability of an animal to understand their image has been captured, more than an animal's actual awareness of their own self.

[edit] Deception, empathy, and theory of mind

Related to the issue of self-consciousness is the question of whether an animal can show empathy, i.e. can understand what another animal is thinking. It is usually argued that to show empathy requires you to have a theory of mind, i.e. to attribute mental processes to other individuals, and that without a theory of mind it is impossible for an animal or person to show tactical deception. Experiments to test for theory of mind in animals have mainly been carried out on primates. No convincing evidence has been found for theory of mind in any primate species other than the great apes; the interpretation of the data from great apes is currently controversial, but some researchers are convinced that they do show theory of mind.

[edit] Emotion

The question of whether animals have emotions, that is, feelings, and if those are qualitatively the same as humans' feelings or in fact simple stimulus responses, is under debate at the moment. See Emotion in animals.

[edit] Continuing controversy

The broad program of research into animal cognition has achieved a good deal. Nonetheless, its results and philosophy continue to be debated, on a number of grounds:

  • Particular issues within animal cognition, particularly the interpretation of language-learning and self-awareness experiments, have generated major controversies both about the extent of the animals' achievements, and about the correct interpretation of the behavior observed.
  • Cognitive scientists have been interested in comparing and contrasting human cognition with artificial intelligence or machine cognition, but have been less interested in including animal cognition in the analysis - despite the fact that the common biological origins of human and animal cognition suggest that there might be greater resemblance, at least in some respects, between human and animal cognition than between human and machine cognition. There is also a minority of cognitive scientists who simply neglect accumulated psychological knowledge about cognition, whether animal or human.
  • Those psychologists who are committed to radical behaviorism and the experimental analysis of behaviour discount cognitive analyses of animal behavior. This is not surprising since for the most part they also reject cognitive analyses of human behaviour, and it is perhaps a category error: in so far as the study of animal cognition exposes new behavioural phenomena, it simply provides more that a radical behaviourist must explain without using mentalistic language.

[edit] Relative intelligence of different animal species

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There are people who have viewed some animals as more intelligent than others: dogs, horses, great apes, elephants, and (more recently) dolphins, crows, and parrots are seen as intelligent in ways that other animals are not. Crows have been attributed with humanlike intelligence by almost every culture that has encountered them. A number of recent survey studies have demonstrated the consistency of these rankings between people in a given culture. A common image is the scala naturae, the ladder of nature on which animals of different species occupy successively higher rungs, with humans typically at the top. Comparative psychologists have sought in vain for ways of providing an objective underpinning for these essentially subjective and anthropocentric judgements. Part of the difficulty is the lack of agreement about what we mean by intelligence even in humans (it obviously makes a big difference whether language is considered as essential for intelligence, for example).

Different animals seem to have different kinds of cognitive processes, which are better understood in terms of the ways in which they are cognitively adapted to their different ecological niches, than by positing any kind of hierarchy. One question that can be asked coherently is how far different species are intelligent in the same ways as humans are, i.e. are their cognitive processes similar to ours. Not surprisingly, our closest biological relatives, the great apes, tend to do best on such an assessment. It is less clear that the species traditionally held to be intelligent do unusually well against this standard, though among the birds, corvids and parrots typically are found to perform above average.

Domesticated animals tend to perform well, however the issues between unintentional human bias towards obedience and conditioned response associated with domestication makes the values of these assertions dubious at best. Another contentious issue is the more popularized rivalry between man's oldest companions, the dog and cat. Studies have put forth the superiority of intelligence in both camps, but its is generally more widely recognized that comparative analysis between them (and other species of similar disposition) is spurious and difficult at best greatly due to the huge differences in their behavioral (instinctual) priorities (cats being more solitary predators and dogs more prone to pack survival).

When examining intelligence separating instinct from higher thought is almost impossible to effectively quantify, though it is an important component for effective comparison between species, most importantly for comparing it to the human species as a point of reference. Thus the question inevitably arises of whether or not a given animal is reacting to certain stimuli through deliberate cognitive reasoning, or by instinctual drive.

Despite ambitious claims, evidence of unusually high human-like intelligence among cetaceans is patchy, partly because the cost and difficulty of carrying out research with marine mammals mean that experiments frequently suffer from small sample sizes and inadequate controls and replication. Octopuses have also been reported to exhibit a number of higher-level problem-solving skills, but cephalopod intelligence apparently hasn't been sufficiently researched, as the validity of most findings is still contested. Of the parrot family, the African Grey Parrot is understood to be the most intelligent.

The most intelligent, according to widespread belief, and most studied in relation to intelligence are the following species:

  • dolphins - most intelligent ocean species (playful, whales have brains of up to 10kg)
  • elephants - most intelligent herbivore species, also more intelligent than any carnivore (capable of art, tool use, playful, brains up to 5 kg)
  • apes - with humans being the most intelligent of them all (brains up to 2 kg)
  • carnivores - considered intelligent by pet owners, with cats, dogs and foxes mostly appreciated for their predatory cunning, necesary for survival (brains weight under 1kg, several hundred grams; 250g for lions, 70 g for dogs and 40 g for domestic cats)
  • other domesticated species, like horses, cows and pigs are considered intelligent. Some other, like oxes are famed for their herd animal stupidity (brains under 1 kg, several hundred grams)
  • parrots and crows - most intelligent birds, together with owls - traditionally the wisest of birds (brains up to 30 grams, capable of many tricks)
  • sharks and rays - most intelligent fishes (brains up to 100g; 35 g for white shark; other fishes have brains few grams at most, though elephantnose fish has a very large brain (2g) for its size, and brain to body mass ratio 1:50, and is capable of sophisticated electrolocation)
  • cephalopodes - most intelligent invertebrates (brains up to 20 grams, larger than almost any non-mammial marine life)

[edit] See also

[edit] References

  1. ^ http://desmoinesregister.com/apps/pbcs.dll/article?AID=/20070223/NEWS/702230385/-1/NEWS04
  2. ^ http://news.nationalgeographic.com/news/2007/02/070222-chimps-spears.html
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