Ethology
Ethology is a branch of zoology concerned with the study of animal behavior. Ethologists study a range of animal behaviors including sexual selection, social behavior, kinship, reciprocity and cooperation, parental investment, conflict and aggression. (comparative approach – usually studies one behavior comparatively across a variety of species)
Methodologically, ethologists engage in hypothesis-driven experimental investigation, often in the field. This combination of lab work with field study reflects an important underpinning of the discipline: behavior is assumed to be adaptive to the species’ natural environment. (Only animals have nervous systems, with their implications for perception, coordination, orientation, learning, and memory)
Ethology emerged as a discrete discipline in the 1920s; its founding practitioners, themselves influenced by the German ornithologist Oskar Heinroth, were Konrad Lorenz, Karl von Frisch, and Niko Tinbergen, who were jointly awarded the 1973 Nobel Prize in Physiology or Medicine for their contributions to the study of behavior. (maybe construe them as popularizers and synthesizers of foundational earlier work of Douglas Spalding, Heinroth, C. Lloyd Morgan, Herbert Spencer Jennings, et al.)
One of the key ideas of classical ethology is the concept of fixed action patterns (FAPs). FAPs are instinctive behaviors that will occur reliably in a member of a species in response to an identifiable stimulus from the environment. For example, at the sight of a displaced egg near the next, the greylag goose will roll the egg back to the others with its beak. If the egg is removed, the animal continues to engage in egg-rolling behavior, pulling its head back as if an imaginary egg is still being maneuvered by the underside of its beak. It will also attempt to move other egg-shaped objects, such as a golf ball, doorknob, or even an egg too large to have been laid by the goose itself (Tinbergen, 1991).
Classical ethology spawned problematic grand theories about internal control mechanisms and the extent to which they were genetically hardwired (innate or instinctive, according to the terminology). (what do we think today that's different – a model that has since been revised to do xyz)
Although ethology as a disciplinary label has largely faded from use, the desire to understand the animal world has made ethology's intellectual inheritors – such as behavioral ecology and evolutionary psychology – rapidly growing fields. Today, students of animal behavior tend to place greater emphasis on social relationships (rather than the individual as variable); however, these studies retain ethology’s tradition of hypothesis-driven investigation and its grounding in evolutionary theory.
Relation to comparative psychology
In order to illuminate the concepts and methods that underlie ethological study, it might be helpful to compare classical ethology to early work in comparative psychology, an alternative approach to the study of animal behavior:
- Comparative psychology construes its study as a branch of psychology rather than as an outgrowth of biology. Thus, where comparative psychology sees the study of animal behavior in the context of what is known about human psychology, ethology situates animal behavior in the context of what is known about animal anatomy, physiology, neurobiology, and phylogenetic history.
- Comparative psychologists are interested more in similarities than differences in behavior; they are seeking general laws of behavior, especially relating to development, which could be applied to all animal species, including humans. Hence, early comparative psychologists concentrated on gaining extensive knowledge of the behavior of a handful of species, while ethologists were more interested in gaining knowledge of behavior in a wide range of species in order to be able to make principled comparisons across taxonomic groups.
- Ethologists focus primarily on lab experiments involving a handful of species, mainly rats and pigeons, whereas ethologists concentrated on behavior in natural situations.
In sum, comparative psychology studies general processes, while ethology focuses on adaptive specialization. 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, ethology, which had developed in Europe, failed to gain a strong foothold in North America, where comparative psychology was dominant. Since the 1970s, animal behavior has become an integrated discipline, with comparative psychologists and ethological animal behaviorists working on similar problems and publishing side by side in the same journals.
Methodology
Tinbergen's four questions for ethologists
The practice of ethological investigation is grounded in the scientific method of hypothesis-driven experimentation. Lorenz's collaborator, Niko Tinbergen, argued that ethologists should consider the following four categories when attempting to formulate a hypothesis that explains any instance of behavior:
- Function: how does the behavior impact the animal's chance of survival and reproduction?
- Mechanism: what are the stimuli that elicit the response? How has the response been modified by recent learning?
- Development: how does the behavior change with age? What early experiences are necessary for the behavior to be demonstrated?
- Evolutionary history: how does the behavior compare with similar behavior in related species? How might the behavior have arisen through the process of phylogeny (the development of the species, genus, or group)?
Using fieldwork to test hypotheses
As an example of how an ethologist might approach a question about animal behavior, consider the study of hearing in an echolocating bat. A species of bat may use frequency chirps to probe the environment while in flight. A traditional neuroscientific study of the auditory system of the bat would involve anesthetizing it, performing a craniotomy to insert recording electrodes in its brain, and then recording neural responses to pure tone stimuli played from loudspeakers. In contrast, an ideal ethological study would attempt to replicate the natural conditions of the animal as closely as possible. It would involve recording from the animal’s brain while it is awake, producing its natural calls while performing some natural behavior such as insect capture.
Key principles and concepts
Behaviors are adaptive responses to natural selection
Because ethology is understood as a branch of biology, ethologists have been particularly concerned with the evolution of behavior and the understanding of behavior 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 Man and Animals (1872) has influenced many ethologists. (Darwin’s protégé George Romanes became one of the founders of comparative psychology, positing a similarity of cognitive processes and mechanisms between animals and humans.) need another sentence ab. Evolutionary underpinnings.
Animals use fixed action patterns in communication
As mentioned above, a fixed action pattern (FAP) is an instinctive behavioral sequence produced by a neural network known as the innate releasing mechanism in response to an external sensory stimulus called the sign stimulus or releaser. Once identified by ethologists, FAPs can be compared across species, contrasting similarities and differences in behavior to similarities and differences in form (morphology).
An example of how FAPs work in animal communication is the classic investigation by Austrian ethologist Karl von Frisch of the so-called "dance language" underlying bee communication. The dance is a mechanism for successful foragers to recruit members of the colony to new sources of nectar or pollen.
Imprinting is a behavior involved in learning
Imprinting describes any kind of phase-sensitive learning (i.e., learning occurring at a particular age or life stage) that is rapid and apparently independent of the consequences of behavior. It was first used to describe situations in which an animal or person learns the characteristics of some stimulus, which is therefore said to be "imprinted" onto the subject.
The best known form of imprinting is filial imprinting, in which a young animal learns the characteristics of its parent. 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. Lorenz demonstrated how incubator-hatched geese would imprint on the first suitable moving stimulus they saw within what he called a "critical period" of about 36 hours shortly after hatching. Most famously, the goslings would imprint on Lorenz himself (more specifically, on his wading boots).
Something on sexual imprinting, which occurs at a later stage? Sexual imprinting is the process by which a young animal learns the characteristics of a desirable mate. For example, male zebra finches appear to prefer mates with the appearance of the female bird that rears them, rather than mates of their own type (Immelmann, 1972).
Reverse sexual imprinting is also seen: when two people live in close domestic proximity during the first few years in the life of either one, both are desensitized to later close sexual attraction and capture-bonding. This phenomenon, known as the Westermarck effect, was first formally described by anthropologist Edvard Westermarck. The Westermarck effect has since been observed in many places and cultures, including in the Israeli kibbutz system, and the Chinese Shim-pua marriage customs, as well as in biological-related families.
In the case of the Israeli kibbutz farms, children were reared somewhat communally in peer groups - groups based on age, not biological relation. A study of the marriage patterns of these children later in life revealed that out of the nearly 3,000 marriages that occurred across the kibbutz system, only fourteen were between children from the same peer group. Of those fourteen, none had been reared together during the first six years of life. This result provides evidence not only that the Westermarck effect is demonstrable, but that it operates during the critical period from birth to the age of six (Shepher, 1983).
When close proximity during this critical period does not occur - for example, where a brother and sister are brought up separately, never meeting one another - they may find one another highly sexually attractive when they meet as adults. This observation is consistent with the theory that the Westermarck effect evolved to suppress inbreeding.
Recent developments in the field
In 1970, the English ethologist John H. Crook published an important paper in which he distinguished comparative ethology from social ethology. He argued that the ethological studies published to date had focused on the former approach—looking at animals as individuals—whereas in the future ethologists would need to concentrate on the social behavior of animal groups.
Since the appearance of E. O. Wilson's seminal book Sociobiology: The New Synthesis in1975, ethology has indeed been much more concerned with the social aspects of behavior, such as phenotypic altruism and cooperation. Research has also been driven by a more sophisticated version of evolutionary theory associated with Wilson and Richard Dawkins.
Furthermore, a substantial rapprochement with comparative psychology has occurred, so the modern scientific study of behavior offers a more or less seamless spectrum of approaches – from animal cognition to more traditional comparative psychology, ethology, and behavioral ecology. Evolutionary psychology, an extension of behavioral ecology, looks at commonalities of cognitive processes in humans and other animals as we might expect natural selection to have shaped them.
History of the term
The term "ethology" is derived from the Greek word "ethos" (ήθος), meaning "custom." Other words derived from the Greek word "ethos" include "ethics" and "ethical." The term was first popularized 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 for this purpose was never adopted.
List of influential ethologists
The following list represents a survey of scientists who have made notable contributions to the field of ethology (many are comparative psychologists):
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ReferencesISBN links support NWE through referral fees
- Barnard, C. 2004. Animal Behaviour: Mechanism, Development, Function and Evolution. Harlow, England: Pearson/Prentice Hall. ISBN 0-130-89936-4
- Tinbergen, N. 1991. The Study of Instinct. Reprint ed. New York: Oxford University Press. ISBN 0-198-57722-2
- might need to add refs from inbreeding section
Further reading
- Klein, Z. 2000. The ethological approach to the study of human behaviour. Neuroendocrinology Letters 21:477-81.
External links
- Most popular Internet platform for animal behaviour
- Konrad Lorenz Institute for Evolution and Cognitive Research (KLI)
- Center for the Integrative Study of Animal behaviour (CISAB)
- Introduction to ethology
- Applied Ethology
- The International Society for Human Ethology - aims at promoting ethological perspectives in the scientific study of humans worldwide
- The Four Areas of Biology
- The Four Areas of Biology AND levels of inquiry
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