The Science of Animal Behavior

The Science of Animal Behavior
Behavioral biologists have traditionally asked two kinds of questions about behavior: how animals behave and why they behave as they do. “How” questions are concerned with immediate or proximate causation. For example, a biologist might wish to explain the singing of a male whitethroated sparrow in the spring in terms of hormonal or neural mechanisms. Such physiological or mechanistic causes of behavior are proximate factors. Alternatively, a biologist might ask what function singing serves the sparrow, and then seek to understand those events in the ancestry of birds that led to springtime singing. These are “why” questions that focus on ultimate causation, the evolutionary origin and purpose of a behavior. These are really independent approaches to behavior, because understanding how the sparrow sings does not depend on what function singing serves, and vice versa. Students of animal behavior consider this distinction significant. Studies of proximate and ultimate causation are both important, but each may be of limited value in understanding the other.

The study of animal behavior has arisen from several different historical roots, and there is no universally accepted term for the whole subject. Comparative psychology emerged from efforts to find general laws of behavior that would apply to many species, including humans. Early research that depended heavily on inference was later replaced by replicable experimental approaches that concentrated on a few species, particularly white rats, pigeons, dogs, and occasionally primates. Following criticisms that the discipline lacked an evolutionary perspective and focused too narrowly on the white rat as a model for other organisms, many comparative psychologists developed more truly comparative investigations, some of these conducted in the field.

The aim of a second approach, ethology, has been to describe the behavior of an animal in its natural habitat. Most ethologists have been zoologists. Their laboratory has been the out-of-doors, and early ethologists gathered their data by field observation. They also conducted experiments, often with nature providing the variables, but increasingly ethologists have manipulated the variables for their own purposes by using animal models, playing recordings of animal vocalizations and altering the habitat. Modern ethologists also conduct many experiments in the laboratory where they can test their predictions under closely controlled conditions. However, ethologists usually take pains to compare laboratory observations with observations of free-ranging animals in undisturbed natural environments.

Ethology emphasizes the importance of ultimate factors affecting behavior. One of the great contributions of von Frisch, Lorenz, and Tinbergen was to demonstrate that behavioral traits are measurable entities like anatomical or physiological traits. This was to become the central theme of ethology: behavioral traits can be isolated and measured and they have evolutionary histories.

Sociobiology, the ethological study of social behavior, originated with the 1975 publication of E. O. Wilson’s Sociobiology: The New Synthesis. Wilson describes social behavior as reciprocal communication of a cooperative nature (transcending mere sexual activity) that permits a group of organisms of the same species to become organized in a cooperative manner. In a complex system of social interactions, individuals are highly dependent on others for their daily living. While social behavior appears in many groups of animals, Wilson identified four “pinnacles” of complex social behavior. These are (1) colonial invertebrates, such as the Portuguese manof- war, which is a tightly-knit composite of individual organisms; (2) social insects, such as ants, bees, and termites, which have developed sophisticated systems of communication; (3) nonhuman mammals, such as dolphins, elephants, and some primates, which have highly developed social systems; and (4) humans.

The inclusion by Wilson of human behavior in sociobiology, and his references to the genetic foundation of many human social behaviors, has been strongly criticized. Complex systems of human social interactions, including religion, economic systems, and such objectionable characteristics as racism, sexism, and war, are emergent properties of human culture and its history. Is it meaningful to search for a specific genetic basis or justification for such phenomena? Many would answer “no,” and look instead to the field of sociology, rather than sociobiology, to help us understand the complex, emergent properties of human societies.

Much of the work by comparative psychologists, ethologists, and those studying sociobiology can be found under the discipline of behavioral ecology. Behavioral ecologists often focus on how individuals are expected to behave to maximize their reproductive success. They then concentrate on a particular aspect of behavior, such as mate choice, foraging or parental investment.