Animal Learning and Cognition

An Introduction

John M. Pearce

• Publisher: Psychology Press
• Year: 2013
• ISBN:
  9781317709930
• Edition: 3
• Topic: Psychology
• Subtopic: Cognitive Psychology & Cognition
• Index: Psychology

Animal Learning and Cognition: An Introduction provides an up-to-date review of the principal findings from more than a century of research into animal intelligence. This new edition has been expanded to take account of the many exciting developments that have occurred over the last ten years.

The book opens with a historical survey of the methods that have been used to study animal intelligence, and follows by summarizing the contribution made by learning processes to intelligent behavior. Topics include Pavlovian and instrumental conditioning, discrimination learning, and categorization. The remainder of the book focuses on animal cognition and covers such topics as memory, navigation, social learning, language and communication, and knowledge representation. Expanded areas include extinction (to which an entire chapter is now devoted), navigation in insects, episodic memory in birds, imitation in birds and primates, and the debate about whether primates are aware of mental states in themselves and others. Issues raised throughout the book are reviewed in a concluding chapter that examines how intelligence is distributed throughout the animal kingdom.

The broad spectrum of topics covered in this book ensures that it will be of interest to students of psychology, biology, zoology, and neuroscience. Since very little background knowledge is required, the book will be of equal value to anyone simply interested in either animal intelligence, or the animal origins of human intelligence.

This textbook is accompanied by online instructor resources which are free of charge to departments who adopt this book as their text. They include chapter-by-chapter lecture slides, an interactive chapter-by-chapter multiple-choice question test bank, and multiple-choice questions in paper and pen format.

The study of animal intelligence

DOI: 10.4324/9781315782911-1

• The Distribution of Intelligence
• Defining Animal Intelligence
• Why Study Animal Intelligence?
• Methods for Studying Animal Intelligence
• Historical Background

A book dedicated to the study of animal learning and cognition is, in the broadest sense, concerned with understanding animal intelligence. Thus the present book will address questions of the following kind: What is animal intelligence? How does it differ from human intelligence? If there is a difference between the intelligence of humans and animals, why should this be? In what way do species of animals differ in their intelligence? How can animal intelligence be measured? None of these is an easy question to answer, and it is partly the difficulty of answering the first that makes it so difficult to answer all others.

This book examines a particular account of animal intelligence. It presumes that animals, like humans, possess a number of mental or cognitive processes and that these collectively contribute to an animal’s intelligence. Thus the way animals remember, learn, reason, solve problems, communicate, and so forth will be examined in some detail. One advantage of this approach is that it permits relatively straightforward answers to the questions posed earlier. For instance, a scale of intelligence might be constructed by ranking animals according to the number of the intellectual abilities they possess. Alternatively, it might turn out that it would be nonsensical to construct any such scale because a species better endowed than another with one of these abilities might be less well endowed with a second. In addition, as this account is based on a human model, it should readily permit the comparison of human and animal intelligence. The chapters that follow examine in some detail the various intellectual capacities that have been revealed in animals and—to a lesser extent—look at the way animals differ in their possession of these capacities. The purpose of the present chapter is to provide a background to this discussion by considering a number of preliminary issues:

1. A popular view of animal intelligence is that there is a growth of this capacity with evolutionary development; apes are therefore seen by many as being more intelligent than most other animals. Although common, this view deserves critical analysis, as it rests on questionable assumptions.
2. The study of animal intelligence is of interest in its own right, but this might be seen as insufficient justification for devoting a book to the topic. The study of human intelligence might be considered a more proper part of psychology. It is therefore worth identifying some of the benefits that can derive from the study of the mental life of animals.
3. The study of mental processes in animals is difficult because the subject matter is not available for direct observation. It is impossible at present to point at any event that can be regarded as a mental process in animals. As a result, special methods must be employed for the study of animal cognition, and the rationale for these needs discussion.
4. Much of the research discussed in this book relates to work conducted during the last thirty years or so, but the study of animal intelligence in the laboratory has now been pursued for over a hundred years. By way of providing a historical background to the rest of the book, the final section of the chapter presents a brief review of the dominant theoretical themes of this work.

The Distribution of Intelligence

Nakajima, Arimitsu, and Lattal (2002) asked university students in both Japan and the USA to rank the intelligence of a variety of animals relative to that of humans (who were assigned 100 points). The results from the survey, which can be seen in Table 1.1, revealed that chimpanzees were regarded as being the most intelligent animal and amoeba the least. The implication of this study is that most of us assume there is a progressive development of intelligence throughout the animal kingdom, culminating with our own species being the most intelligent.

Table 1.1 The rank order of the 56 animals students were asked by Nakajima et al. (2002) to score on intelligence, together with the means score assigned to each species. The maximum score was 100

Animal	Score	Animal	Score	Animal	Score	Animal	Score
Chimpanzee	77	Kangaroo	50	Penguin	40	Tuna	25
Orangutan	72	Panda	48	Rabbit	39	Octopus	24
Dolphin	72	Hawk	48	Ostrich	38	Lizard	24
Gorilla	68	Parrot	48	Crocodile	37	Ant	23
Dog	61	Sea lion	48	Rat	35	Frog	23
Baboon	60	Crow	46	Pigeon	33	Carp	22
Whale	57	Cow	45	Sparrow	32	Crab	20
Wolf	56	Giraffe	44	Quail	31	Cockroach	19
Cat	55	Owl	44	Fowl	31	Goldfish	19
Lion	54	Shark	43	Mole	31	Butterfly	17
Bear	52	Sheep	42	Snake	30	Jellyfish	15
Horse	52	Bat	41	Salmon	29	Earthworm	10
Fox	51	Koala	41	Turtle	28	Slug	10
Elephant	50	Pig	41	Honeybee	28	Ameba	8

I shall examine two popular justifications for the assumption that intelligence is distributed in this way. One is based on an interpretation of evolution that presumes that animals can be arranged in a sequence according to their phylogenetic status. The other is derived from the assumption that there is a relationship between intelligence and brain size. In fact, neither of these justifies the views expressed by the students questioned by Nakajima et al. (2002).

The role of evolution

Since the time of Aristotle (384–322 bc), attempts have been made to represent the animal kingdom in an orderly sequence. Such a sequence has been referred to as the scala naturae or the “great chain of being”. Typically, the lower rankings of these scales are occupied by formless creatures like sponges, whereas the upper echelons are reserved for humans. Ascending through the intermediate range of these scales can be found insects, fish, amphibians, reptiles, and various mammals. According to Aristotle, elephants were placed just below humans. Although these scales generally end with our own species, this has by no means been a universal practice. Occasionally the “great chain” has extended beyond humans to include angels and, ultimately, God.

Key Term

Scala naturae

A classical conception in which everything in the universe was assigned a place in a strict hierarchical sequence.

Various justifications have been proposed for such a simple ordering. Aristotle based his scheme on whether the animals possessed blood and on the number of their legs. More recently, evolutionary terms have been used to justify what is now referred to as the phyletic or phylogenetic scale. Since the publication of Darwin’s On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life, in 1859, it has become accepted that all existing species have descended or evolved from different, earlier species. As a result, it is possible to envisage a chain of evolution in which the earliest animals are placed at the bottom, and the species they led to are placed above them in the order of their appearance. Homo sapiens appeared some 100,000 years ago and would be very near the top of this scale. Most would accept that humans are vastly more intelligent than the protozoa to which we are distantly related, and so it is not difficult to regard the phyletic scale as roughly corresponding to the intellectual development of the species ordered along it. This interpretation could hardly be more incorrect.

Key Terms

Phylogenetic scale

A sequence in which all livings things are ordered according to their complexity. The scale has, at times, been justified erroneously on evolutionary grounds.

Evolution

The change in the inherited characteristics of a species from one generation to the next.

While on his voyage around South America on HMS Beagle, Darwin noted that the iguanas on the Galapagos Islands were different from those on the mainland in that only the former ate seaweed and swam in the sea. To explain this difference between such closely related species, he developed the principle of natural selection, which is based on two observations:

1. Many more animals are born than achieve reproductive success; some die before reaching sexual maturity, others might fail to find a mate.
2. The individuals of a given species are not identical but differ from one another in a variety of ways.

It follows from these observations that certain members of a species will be better suited than others to survive in a given environment, and will be more likely to mature sexually and to leave offspring. If we assume that offspring resemble their parents, it further follows that better-adapted characteristics will spread through a population at the expense of less well-adapted characteristics. If members of the same species should occupy different environments, the different demands they face will favor the reproduction of animals with slightly different characteristics. Eventually, their characteristics might have diverged to such an extent that they can no longer interbreed successfully, and they will constitute separate species.

Presumably, then, the ancestors of the iguanas observed by Darwin on the Galapagos Islands and on the mainland of South America were of the same stock. However, the radically different nature of these two environments—an abundance of seaweed and a dearth of vegetation on the islands, and a proliferation of vegetation on the mainland—would have favored the gradual development of different characteristics in successive generations of offspring from the common ancestor.

One important implication of this account is that the notion of a phylogenetic scale is a gross oversimplification of the history of evolution. Instead of one species evolving from another in a strict sequence, as the “great chain of ...