begun, we can get a fair picture of the type of activity to be seen and of the method of studying this equipment. . . . At birth or soon thereafter we find nearly all of the socalled clinical neurological signs or reflexes established, such as the reaction of the pupil to light, the patellar reflex and others. We find the birth cry followed forever afterward by breathing, the heartbeat and all circulatory phenomena, such as vasomotor constriction (decrease in diameter of vessels) and dilatation, pulse beat, etc. Beginning with the alimentary tract, we find sucking, tongue movements, and swallowing. We find hunger contractions, digestion, necessitating glandular reactions in the whole alimentary tract and elimination (defæcation, urination, sweat). The acts of smiling, sneezing, and hiccoughing belong in part at least to the alimentary canal system. . . We find general movements of the trunk, head and neck best observed, so far as the trunk is concerned, when the infant suspends himself with the hands. Rhythmical "climbing" movements then appear. We can see the trunk at work in breathing, when the infant cries, during defæcation and urination, when turning over or when the head is raised or turned. We find the arms, wrist, hands and fingers in almost ceaseless activity (the thumb rarely taking part until later). In this activity especially are to be noted: grasping, opening and closing hands repeatedly, "slashing" about of the whole arm, putting hand or fingers into mouth, throwing arm and fingers to face when nose is held. We find the legs, ankles, foot and fingers in almost ceaseless movement except in sleep and even during sleep if external (and internal) stimuli are present. The knee can be bent, leg moved at hip, ankle turned, toes spread, etc. If the bottom of the foot is touched, there is a characteristic movement of the toes (Babinski reflex); if the left knee is pinched the right foot is brought up to the point of stimulation and vice versa. Other activities appear at a later stage-such as blinking, reaching, handling, handedness, crawling, standing, sitting up, walking, running, jumping. In the great majority of these later activities it is difficult to say how much of the act as a whole is due to training or conditioning. A considerable part is unquestionably due to the growth changes in structure, and the rest is due to training and conditioning. . . . Actual observation (of infants) thus makes it impossible for us any longer to entertain the concept of instinct. We have seen that every act has a genetic history. . . . In order that you may more easily grasp one of the central principles of behaviorism-viz., that all complex behavior is a growth or development out of simple resources, I want to introduce here the notion of "activity stream.. We have passed in review many of the known facts on the early behavior of the human infant. Let us draw a diagram [Fig. 11] to represent the whole increasing complexity of man's organization. This picture will be very incomplete for several reasons. In the first place we have room on the chart to show only a few of those activities. In the second place our studies are not complete enough to draw an adequate chart even if we had the space, and finally we will not have the time to take up in these lectures man's visceral and emotional equipment, his manual habits and his language habits. In spite of these handicaps, though, try to think of a complete life chart-of the ceaseless stream of activity beginning when the egg is fertilized and ever becoming more complex as age increases. Some of the unlearned acts we perform are shortlived-they stay in the stream only a little time-such, for example, as suckling, unlearned grasping (as opposed to learned grasping and manipulation), extension of the great toe (Babinski), etc., then disappear forever from the stream. Try to think of others beginning later in life, e.g., blinking, menstruation, etc., and remaining in the stream-blinking until death; menstruation until, say, 45-55 years, then disappearing.. But try hardest of all to think of each unlearned act as becoming conditioned shortly after birth-even our respiration and circulation. Try to remember, too, that the unlearned movements of arms, hands, trunks, legs, feet and toes become organized quickly into our stabilized habits, some of which remain in the stream throughout life, others staying in only a short time and then disappearing forever. For example, our 2-year habits must give place to 3- and 4-year habits. 18. Instincts in the Nursery [WATSON, John B., "What the Nursery Has to Say About Instincts" (Powell Lecture in Psychology at Clark University, January 16, 1925), Pedagogical Seminary and The Journal of Genetic Psychology, June, 1925, Vol. 32, pp. 293-327.] Man is an animal born with certain definite types of structure. Having that kind of structure, he is forced to respond to stimuli at birth in certain ways (for example: breathing, heart FIG. 11. THE ACTIVITY STREAM. Rough diagram showing increasing complexity of certain human ac tion systems. The black solid line shows the unlearned beginning of each system. The dotted line shows how each system is made complex by conditioning it. Some of the systems apparently are not modified. They exist in the stream throughout life without increasing in complexity. The chart is neither complete nor accurate. Until more thorough genetic work has been done, a chart of this kind cannot be used as a measuring rod of what to expect of infants of different ages. beat, sneezing, and the like). This repertoire of responses is in general the same for each of us. Yet there exists a certain amount of variation in each-the variation is probably merely proportional to the variation there is in structure (including in structure, of course, chemical constitution). It is the same repertoire now that it was when the genus homo first appeared many millions of years ago. Let us call this group of reactions, man's unlearned behavior. In this relatively simple list of human responses there is none corresponding to what is called an "instinct" by present day psychologists and biologists. There are then for us no instincts we no longer need the term in psychology. Everything we have been in the habit of calling an "instinct" to-day is a result largely of training-belonging to man's learned behavior. As a corollary from this, I wish to draw the conclusion that there is no such thing as an inheritance of capacity, talent, temperament, mental constitution and characteristics. These things again depend on training that goes on mainly in the cradle. The behaviorist would not say, "He inherits his father's capacity or talent for being a fine swordsman." He would say: "This child certainly has his father's slender build of body, the same type of eyes. His build is wonderfully like his father's. He, too, has the build of a swordsman." And he would go on to say: "—and his father is very fond of him. He put a tiny sword into his hand when he was a year of age, and in all their walks he talks sword play, attack and defense, the code of dueling and the like." A certain type of structure, plus early trainingslanting-accounts for adult performance. . ... So let us hasten to admit-yes, there are heritable differences in form, in structure. Some people are born with long, slender fingers, with delicate throat structure; some are born tall, large, of prize-fighter build; others with delicate skin and eye coloring. These differences are in the germ plasm and are handed down from parent to child. More questionable are the inheritance of such things as the early or late graying of hair, the early loss of hair, the span of life, the bearing of twins, and the like. Many of these questions have already been answered by the biologists and many others are in the process of being answered. But do not let these undoubted facts of inheritance lead you astray. . . . The mere presence of these structures tell you not one thing about function. This has been the source of a great deal of confusion in the subject we have under consideration. Much of our structure laid down in heredity would never come to light, would never show in function, unless the organism were put in a certain environment, subjected to certain stimuli and forced to undergo training. Our hereditary structure lies ready to be shaped in a thousand different ways-the same structure mind you-depending on the way in which the child is brought up.... The fact that there are marked individual variations in structure among men has been known since biology began. But we have never sufficiently utilized it in analyzing man's behavior. I want to utilize still another fact only recently brought out by the behaviorists and other students of animal psychology, namely, that habit formation starts in all probability in embryonic life, and that even in the human young, environment shapes behavior so quickly that all of the older ideas about what types of behavior are inherited and what are learned break down. Grant variations in structure at birth and rapid habit formation from birth, and you have a basis for explaining many of the so-called facts of inheritance of "mental" characteristics. Let us take up these two points: 1. Human Beings Differ in the Way They Are Put Together 2. Differences in Early Training Make Man Still More Different Our conclusion, then, is that we have no real evidence of the inheritance of traits. I would feel perfectly confident in the ultimately favorable outcome of careful upbringing of a healthy, well-formed baby born of a long line of crooks, murderers, thieves and prostitutes. Who has any evidence to the contrary? Many, many thousands of children yearly, born from moral households and steadfast parents, become wayward, steal or become prostitutes, through one mishap or another of nurture. Many more thousands of sons and daughters of the wicked grow up to be wicked because they couldn't grow up any other way in such surroundings. But let one adopted child who has a bad ancestry go wrong and it is used as incontestable evidence for the inheritance of moral turpitude and criminal tendencies. Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select a doctor, lawyer, artist, merchant-chief, and, yes, even into beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations and race of his ancestors. I am going beyond my facts and I admit it, but so have the advo |