Animal intelligence: Experimental studies

by Edward L. Thorndike

Furthermore, there is no more truth in the statement that a man’s pain or anxiety or opinions are matters of direct consciousness, pure experience, than in the statement that his length, weight and temperature are, or that the sun, moon and stars are. If by the pain we must mean the pain as felt by some one, then by the sun we can mean only the sun as seen by some one. Pain and sun are equally subjects for a science of ‘consciousness as such.’ But if by the sun is meant the sun of common sense, physics and astronomy, the sun as known by any one, then by the pain we can mean the pain of medicine, economics and sociology, the pain as known by any one, and by the sufferer long after he was or had it.

All facts emerge from the matrix of pure experience; but they become facts for science only after they have emerged therefrom. A man’s anxiety may be the anxiety as directly felt by the man, or as thought of by him, or as thought of by the general consensus of scientific observers. But so also may be his body-temperature or weight or the composition of the blood in his veins. There can be no valid reason other than a pragmatic one for studying a man’s anxiety solely as felt by him while studying his body-temperature as thought of by him and others. And the practical reasons are all in favor of studying all facts as they exist for any impartial observer. A man’s mind as it is to thinking men is all that thinking men can deal with and all that they have any interest in dealing with.

Finally, the subject-matter of psychology is not sharply marked off from the subject-matter of physiology by being absolutely non-spatial. On the contrary, the toothache, anxiety and judgment are referred unequivocally, by every sane man who thinks of them, to the space occupied by the body of the individual in question. That is the surest fact about them. It is true that we do not measure the length, height, thickness and weight of an animal’s pain or anxiety, but neither do we those of his pulse, temperature, health, digestion, metabolism, patellar reflex or heliotropism.

Two noteworthy advantages are secured by the study of behavior. First, the evidence about intellect and character offered by action and the influence of intellect and character upon action are given due attention. Second, the connections of conscious states are studied as well as their composition.

The mind or soul of the older psychology was the cause not only of consciousness, but also of modifiability in thought and action. It was the substance or force in man whereby he was sensitive to certain events, was able to make certain movements, and not only had ideas but connected them one with another and with various impressions and acts. It was supposed to account for actual bodily action as well as for the action-consciousness. It explained the connections between ideas as well as their internal composition. If a modern psychologist defines mind as the sum total of consciousness, and lives up to that definition, he omits the larger portion of the task of his predecessors. To define our subject-matter as the nature and behavior of men, beginning where anatomy and physiology leave off, is, on the contrary, to deliberately assume responsibility for the entire heritage. Behavior includes consciousness and action, states of mind and their connections.

Even students devoted to ‘consciousness as such’ must admit that the movements of an animal and their connections with other features of his life deserve study, by even their kind of psychologist. For the fundamental means of knowing that an animal has a certain conscious state are knowledge that it makes certain movements and knowledge of what conscious states are connected with those movements. Knowledge of the action-system of an animal and its connections is a prerequisite to knowledge of its stream of consciousness.

There are better reasons for including the action-system of an animal in the psychologist’s subject-matter. An animal’s conscious stream is of no account to the rest of the world except in so far as it prophesies or modifies his action.[2] There can be no moral warrant for studying man’s nature unless the study will enable us to control his acts. If a psychologist is to study man’s consciousness without relation to movement, he might as well fabricate imaginary consciousnesses to describe and analyze. The lovers of consciousness for its own sake often do this unwittingly, but would scarcely take pride therein!

The truth of the matter is, of course, that an animal’s mind is, by any definition, something intimately associated with his connection-system or means of binding various physical activities to various physical impressions. The whole series—external situations and motor responses as well as their bonds—must be studied to some extent in order to understand whatever we define as mind. The student of behavior, by frankly accepting the task of supplying any needed information not furnished by physiology, and of studying the animal in action as well as in thought, is surer of getting an adequate knowledge of whatever features of an animal’s life may be finally awarded the title of mind.

The second advantage in studying total behavior rather than consciousness as such is that thereby the connections of mental facts one with another and with non-mental facts receive due attention.

The original tendencies to connect certain thoughts, feelings and acts with certain situations—tendencies which we call reflexes, instincts and capacities—are not themselves states of consciousness; nor are the acquired connections which we call habits, associations of ideas, tendencies to attend, select and the like. No state of consciousness bears within itself an account of when and how it will appear, or of what bodily act will be its sequel. What any given person will think in any given situation is unpredictable by mere descriptions and analyses of his previous thoughts each by itself. To understand the when, how and why of states of consciousness one must study other facts than states of consciousness. These non-conscious relations or connections, knowledge of which informs us of the result to come from the action of a given situation on a given animal, may be expected to be fully half of the subject-matter of mental science.