Ethology is the scientific study of animal behaviour, construed as a branch of zoology.
Origins of the name
The term “ethology” was coined in its French form éthologie by the zoologist Isidore Geoffroy Saint-Hilaire. It was first popularised in English by the American Myrmecologist William Morton Wheeler in 1902. An earlier, slightly different sense of the term was proposed by John Stuart Mill in his 1843 System of Logic. He recommended the development of a new science, "ethology," whose purpose would be the explanation of individual and national differences in character, on the basis of associationistic psychology. This use of the word was never adopted, however.
Differences and similarities with comparative psychology
Ethology can be contrasted with comparative psychology, which also studies animal behaviour, but construes its study as a branch of psychology. Thus where comparative psychology sees the study of animal behaviour in the context of what is known about human psychology, ethology sees the study of animal behaviour in the context of what is known about animal anatomy and physiology. Furthermore, early comparative psychologists concentrated on the study of learning, and thus tended to look at behaviour in artificial situations, whereas early ethologists concentrated on behaviour in natural situations, tending to describe it as instinctive. The two approaches are complementary rather than competitive, but they do lead to different perspectives and sometimes to conflicts of opinion about matters of substance. In addition, for most of the twentieth century comparative psychology developed most strongly in North America, while ethology was stronger in Europe, and this led to different emphases as well as somewhat different philosophical underpinnings in the two disciplines. A practical difference is that comparative psychologists concentrated on gaining extensive knowledge of the behaviour of very few species, while ethologists were more interested in gaining knowledge of behaviour in a wide range of species, not least in order to be able to make principled comparisons across taxonomic groups. Ethologists have made much more use of a truly comparative method than comparative psychologists ever have.
Darwinism and the beginnings of ethology
Because ethology is understood as a branch of biology, ethologists have been particularly concerned with the evolution of behaviour and the understanding of behaviour in terms of the theory of natural selection. In one sense the first modern ethologist was Charles Darwin, whose book The expression of the emotions in animals and men influenced many ethologists. However, he pursued his interest in behaviour by encouraging his protégé George Romanes, who investigated animal learning and intelligence using an anthropormorphic method that did not gain scientific support. The early ethologists, such as Oskar Heinroth and Julian Huxley instead concentrated on behaviours that can be called instinctive, or natural, in that they occur in all members of a species under specified circumstances. Their first step in studying the behaviour of a new species was to construct an ethogram, a description of the main types of natural behaviour with their frequencies of occurrence. This approach provided an objective, cumulative base of data about behaviour, which subsequent researchers could check and build on, and as a way of building a science of behaviour, it proved much more fruitful.
The Fixed Action Pattern and animal communication
An important step, associated with the name of Konrad Lorenz though probably due more to his teacher, Heinroth, was the identification of fixed action patterns (FAPs). Lorenz popularized FAPs as instinctive responses that would occur reliably in the presence of identifiable stimuli (called sign stimuli or releasing stimuli). These FAPs could then be compared across species, and the similarities and differences between behaviour compared with the similarities and differences in morphology on which taxonomy was based. An important and much quoted study of the Anatidae (ducks and geese) by Heinroth used this technique. The ethologists noted that the stimuli that released FAPs were commonly features of the appearance or behaviour of other members of their own species, and they were able to show how important forms of animal communication could be mediated by a few simple FAPs. The most sophisticated investigation of this kind was the study by Karl von Frisch of the so-called “dance language” underlying bee communication. Lorenz developed an interesting theory of the evolution of animal communication based on his observations of the nature of fixed action patterns and the circumstances in which animals emit them.
A second important finding of Lorenz concerned the early learning of young nidifugous birds, a process he called imprinting. Lorenz observed that the young of birds such as geese and chickens spontaneously followed their mothers from almost the first day after they were hatched, and he discovered that this following response could be transferred to an arbitrary stimulus if the eggs were incubated artificially and the stimulus was presented during a critical period (now called a sensitive period) that covered the few days after hatching. The concept of imprinting has been widely adopted in developmental psychology.
Tinbergen's four questions for ethologists
Lorenz’s collaborator, Niko Tinbergen, argued that ethology always needed to pay attention to four kinds of explanation of any instance of behaviour:
- function: how does the behaviour impact on the animal’s chances of survival and reproduction?
- causation: what are the stimuli that elicit the response, and how has it been modified by recent learning?
- development: how does the behaviour change with age, and what early experiences are necessary for the behaviour to be shown?
- evolutionary history: how does the behaviour compare with similar behaviour in related species, and how might it have arisen through the process of phylogeny?
The flowering of ethology
Through the work of Lorenz and Tinbergen, ethology developed strongly in continental Europe in the years before World War II
. After the war, Tinbergen moved to the University of Oxford
, and ethology became stronger in the UK
, particularly under the influence leadership of Willard Thorpe, Robert Hinde and Patrick Bateson at the Sub-department of Animal Behaviour of the University of Cambridge
, located in the village of Madingley. In this period, too, ethology began to develop strongly in North America
Lorenz, Tinbergen, and von Frisch were jointly awarded the Nobel Prize in 1973 for their work in developing ethology.
Social ethology and recent developments
In 1970, the English ethologist John H. Crook published an important paper in which he distinguished comparative ethology from social ethology, and argued that much of the ethology that had existed so far was really comparative ethology, looking at animals as individuals, whereas in the future, ethologists would need to concentrate on the behaviour of social groups of animals and the social structure within them. This was prescient. E. O. Wilson’s book ‘’Sociobiology’’ appeared in 1975, and since that time the study of behaviour has been much more concerned with social aspects. It has also been driven by the stronger, but more sophisticated, Darwinism associated with Wilson and his populariser Richard Dawkins. The related development of behavioral ecology has also helped transform ethology. At the same time a substantial rapprochement with comparative psychology has occurred, so the modern scientific study of behaviour offers a more of less seamless spectrum of approaches, from animal cognition, more traditional comparative psychology, ethology, sociobiology and behavioural ecology.
List of ethologists
A list of people who have made notable contributions to the field of ethology: