BEHAVIOR AND BEHAVIORISM. The term behavior was used first to describe the conditions of animal activities, but because of the peculiar relations that exist between the actions of man and animals it has developed into a name for one general explanation of or attitude toward human and animal actions and psychological problems in general. The prob lem as to how the activities of men and of ani mals are related has been discussed from the beginning of thought. For the most part it was assumed that one could know directly the mind of man and that all that remained was to de termine whether and to what degree animals had a similar mind. As there is no direct method of determining whether animals have mental states, the development of scientific analysis compelled the investigator to raise the more definite question of what the criteria of mental activities in animals might be. This again led away from the problem, since an unambiguous answer could not be given to the more general question of what different kinds of acts is the animal capable and what is the explanation of each.
One can trace the gradual development of the notion of behavior as a separate type of organic activity through three stages in the work of the last three decades. The first stage is represented by Loeb, whose experiments on animals led him to the conclusion that one must distinguish two types of control in the responses of animals. The lower animals re spond as plants respond by heliotropism, geotro pism, etc., a response that might very easily be reduced to simple mechanical laws, the con traction of the tissue on the side toward the light and its expansion on the opposite side, e.g., would explain positive heliotropism. The movements of higher animals were explained from the more human analogy as due to °asso ciative tnemory,D the simplest of the learning processes. Bethe a little later made an attempt to explain all actions of animals in purely mechanical and chemical terms. He asserted that movements similar to those of the amceba were made by drops of liquids and could be explained by the action of the surface film under different conditions. From experiments on ants he argued that they too were merely reflex machines, guided largely by the chemical excitations that we call odors. Jennings, in a
long series of experiments, became convinced that there could be no sharp break in the line of development from lower to higher. In at tempting to repeat Bethe's experiments he found that the reactions of the lowest organ isms were by no means as simple as Bethe had assumed. Traces of learning, i.e., modification of responses as a result of earlier responses could be detected even in unicellular organ isms. At the same time he believed nothing was to be gained by assuming consciousness as a cause. To all forms of action he applied • the term ((behavior.) Behavior, then, is a term that designates the activities of animals as wholes. It distin guishes their !movements from the movements of inanimate objects, and at the same tirne does not make reference to consciousness or to any mental state. Behavior as the action of the whole is not referred to the action of the parts as in physiology. In this way it leaves room for an explanation of the organism's activity apart from physiology, although the behaviorist assumes that the laws of physiology must hold and be essential for the explanation of the animal's activity. Instead of analyzing the various acts into the mechanical action of the members, behavior is explained by ref erence to the natural endowment of the organ ism through instinct and particular heredity and to its earlier acts caused by forces in the environment. While originally developed as a negative term to show how animal movements were not to be explained, the term has gradu ally taken on a somewhat positive meaning to designate the explanation of these movements in terms of wider influences. This comes in part from the success of the psychologist and zoologist in determining the laws of behavior in animals. Within the last quarter of a cen tury the laws of learning, certain of the in stincts and the differential responses to stimuli have• been pretty fully determined in many animals ranging from the amceba to the ape_ These together give a fairly satisfactory ex planation of behavior.