There have been throughout these Dark Ages 'voices crying in the wilderness', but they were dismissed as old-fashioned. Thus McDougall (1923) kept reaffirming that the earth was round and that striving towards a goal was often more satisfactory than reaching it. Allport held that activities originally derived from biological needs may become autonomous and self-rewarding: 'The characteristic feature of such striving is its resistance to equilibrium: tension is maintained rather than reduced.' [17] Goldstein emphasized the tendency of organisms towards 'self-actualization' [18] But the revival of a dynamic psychology which reinstated the academic respectability of such terms as curiosity, exploratory drive, purpose, only came about when experimental evidence showed that even in the rat the urge to explore may prevail over hunger and fear.
The experiments of Harlow, Montgomery, Butler, Hudson, etc., on rats and monkeys showed -- what naturalists had always known -- that animals are inquisitive, that they have an urge to manipulate, explore, to 'look what's inside', which is independent from such biological drives as hunger, sex, and fear -- or, rather, that the exploratory drive itself stems from a primary biological need. They showed that exploratory behaviour may combine with, or enter the service of, hunger or fear, but that it may also compete with and sometimes assert itself against them; and that novelty, surprisingness, or puzzlement are as real incentives to learning as pellets of food dropped into the Skinner box. [19]
As far back as 1930 Nissen had found that rats would cross an electrified grill to reach a maze which contained nothing but some unusual objects; he concluded that an exploratory urge did exist -- 'a biogenic drive to explore, perceive, to know'. [20] Experiments by Hudson, Berlyne, and Walley, in which rats were punished for approaching some novel visual pattern, led them to conclude that 'objects that have become associated with danger are often explored before they are shunned'. [21] Carr and Williams [22] showed that the exploratory drive varies with heredity and environment: hooded rats explore more than black rats, and black rats more than Albino rats. Montgomery and Barnett [23] showed that wild rats are more frightened, tame rats more attracted by novelty; Thompson and Heron [24] that young animals are more curious than old ones, and -- as one would expect -- that female rats are more inquisitive than males. [25] Confronted with novel situations, hungry rats interrupt their feeding to explore their surroundings; [26] but rats whose cerebral cortex has been removed in part, while still capable of learning to run a maze to get at food, show a diminished tendency to exploration. They 'do not evince the preference for a variable path over a standardized path that is characteristic of a normal rat, except when the variable path is the shorter. Brain-damaged rats likewise show less variability of route in a Dashiell maze.' [27] Yet, as Lashley's rats have shown, even depriving the creature of substantial portions of its brain does not make it conform to the S.-R. ideal.
On higher levels of the animal kingdom the evidence becomes less monotonous and depressing. What a relief to get out of the Skinner box and to read Lorenz's description of curiosity battling with fear in one of his birds: [28]
A young raven, confronted with a new object, which may be a camera, an old bottle, a stuffed polecat, or anything else first reacts with escape responses. He will fly up to an elevated perch and, from this point of vantage, stare at the object literally for hours. After this, he will begin to approach the object very gradually, maintaining all the while a maximum of caution and the expressive attitude of intense fear. He will cover the last distance from the object hopping sideways with half-raised wings, in the utmost readiness to flee. At last, he will 'deliver a single fearful blow with his powerful beak at the object and forthwith fly back to his safe perch. . . .' In the end 'he will grab [the object] with one foot, peck at it, try to tear 'off pieces, insert his bill into any existing cleft and then pry apart his mandibles with considerable force. Finally, if the object is not too big the raven will carry it away, push it into a convenient hole and cover it with some inconspicuous material.
As for primates, we can comfortably fall back on Darwin's Descent of Man:
All animals feel Wonder, and many exhibit Curiosity. They sometimes suffer from this latter quality, as when the hunter plays antics and thus attracts them; I have witnessed this with deer, and so it is with the wary chamois, and with some kinds of wild-ducks. Brehm gives a curious account of the instinctive dread, which his monkeys exhibited, for snakes; but their curiosity was so great that they could not desist from occasionally satiating their horror in a most human fashion, by lifting up the lid of the box in which the snakes were kept.
Darwin was 'so much surprised at this account' that he proceeded to the monkey-house at the Zoological Gardens armed with a stuffed snake, a dead fish, a mouse, and a live turtle:
The excitement thus caused was one of the most curious spectacles which I ever beheld.' The greatest success was the turtle. The monkeys 'showed unbounded astonishment, as well as some fear. . . . This was displayed by their remaining motionless, staring intently with widely opened eyes, their eyebrows being often moved up and down. Their faces seemed somewhat lengthened. They occasionally raised themselves on their hindlegs to get a better view. They often retreated a few feet, and then turning their heads over one shoulder, again stared intently. . . . In the course of a few minutes some of the monkeys ventured to approach and touch the turtle. . . . I then placed a live snake in a paper bag, with the mouth loosely closed, in one of the larger compartments. One of the monkeys immediately approached, cautiously opened the bag a little, peeped in, and instantly dashed away. Then I witnessed what Brehm has described, for monkey after monkey, with head raised high and turned on one side, could not resist taking a momentary peep into the upright bag, at the dreadful object lying quietly at the bottom. [29]
This was written half a century before Köhler's Mentality of Apes was translated into English -- with a delay of eight years after the appearance of the German original. [30] It had the effect of something like a bombshell on American psychology, in which Pavlov and Watson were all the rage. Yet even Köhler, though he attacked Thorndike, remained essentially conservative as far as motivation is concerned; it took another quarter-century for a new crop of experimentalists to discover, in the 1950s, that the exploration of novelty, the manipulation of objects, the dismantling and reassembling of complex manual puzzles, and even scribbling and drawing were self-rewarding and self-arousing activities.
'Those who have had opportunities to observe monkeys and apes at close hand for prolonged periods invariably dwell on their addiction to looking, mauling, prodding, licking, and generally squeezing every drop of possible entertainment from whatever crosses their path.' [31] Particularly revealing is the fact that Rhesus monkeys who have learned to dismantle a complex manual puzzle of interlocking pieces performed better when there was no food reward put inside the puzzle than when they knew that there was one. In the second case they got impatient and tried short-cuts; in the first case they practised disinterestedly, 'l'art pour l'art'. [32]
The Exploratory Drive
The cumulative evidence of these and similar experiments led Harlow to the conclusion:
There are logical reasons why a drive-reduction theory of learning, a theory which emphasizes the role of internal, physiological-state motivation is entirely untenable as a motivational theory of learning. The condition of strong drive is inimical to all but very limited aspects of learning -- the learning the ways to reduce tension. . . . The hungry child is a most uncurious child, but after he has eaten and become thoroughly sated, his curiosity and all the learned responses associated with his curiosity take place. [33]
Montgomery came to similar conclusions, which he put into the laconic formula: 'Exploratory behaviour is motivated by the exploratory drive.'
These clarion calls of a new generation of experimentalists in fact echoed the earher 'voices in the wilderness' -- such as Woodworth's: 'To see, to hear -- to see clearly, to hear distinctly -- moment by moment, such concrete, immediate mot
ives dominate the life of relation with the environment.' [34] In the meantime, however, these 'old-fashioned' views had received added, powerful support from neurophysiology. Lindsley (1951), Hebb (1955) and others have shifted their attention from tension-reducing, stabilizing processes in the nervous system to the supposedly arousing, attention-sharpening functions of certain structures in the midbrain -- the so-called 'reticular activating system', RAS. Although these theories are still controversial, parallel studies on sensory deprivation have dramatically revealed the deleterious effects of protracted stimulus-starvation, and the organism's need for more or less constant stimulation, or at least a steady inflow of information -- a hunger for experience and thirst for excitation probably as basic as hunger and thirst themselves. Instead of responding passively to the environment, 'human beings and higher animals spend most of their time in a state of relatively high arousal and . . . expose themselves to arousing stimulus situations with great eagerness'. [35] Two thousand years ago Juvenal had said much the same: 'Duas tantum res anxius optat, / Panem et circenses.'
Berlyne [36] has made a systematic survey of the manifestations of the exploratory drive on various levels -- from orientation reflexes to artistic and scientific curiosity. At the bottom of the ladder we have Pavlov's 'investigatory' or 'what is it?' reflex. 'It is this reflex', Pavlov wrote in a famous passage, 'which brings about the immediate response in men and animals to the slightest changes in the world around them, so that they immediately orientate their appropriate receptor-organ in accordance with the perceptible quality in the agent bringing about the change, making full investigation of it.' [37] From true reflexes such as dilatation of the pupil and automatic scanning, we ascend to oculo-motor responses, movements of the head or the whole body towards the stimulating phenomenon: animals prick their ears, tense their muscles, sniff the air 'musingly'. Next comes 'locomotor exploration' which 'appears to be universal among higher vertebrates and present to some degree in other branches of the animal kingdom'; yet, as Berlyne ruefully remarks: 'It has been studied systematically in rather few species. By far the greater part of the relevant literature is concerned with the rat.' According to Darchen [38], even the cockroach is capable of disinterested latent learning, prompted by sheer curiosity; while kittens, puppies, and young chimps seem to spend a major portion of their time in 'locomotive exploration'. Lastly, we come to 'investigatory' or 'inquisitive' behaviour, ranging from Darwin's monkey who cannot refrain from peeping into the snake-infested Pandora's box, to the 'insatiable curiosity' of the artist and explorer.
Thus neuro-physiological considerations, laboratory work with animals, and the observations of ethologists of the Lorenz-Tinbergen school, all seem to converge in the same direction. Even the embryological studies of Coghill (pp. 430 ff.) and Weiss (p. 434 seq.), with their emphasis on spontaneous, intrinsic activities on all levels of the organic hierarchy, lend indirect support to the primacy of the exploratory drive. The lesson of fifty years of rats-in-mazes has been summed up, e.g. by Thacker in the statement that 'motivation for learning is central and neural . . . organized and proliferated cognitive structure itself is the goal towards which learning moves'. [39]
In other words, the motivation for learning is to learn.
Thorpe, for all his habitual caution, has gone even further. He starts with a rhetorical question: 'And so it becomes important to consider how far there is evidence of learning motivated by a general drive quite independent of the motivation of particular instincts'; [40] and he concludes that 'there is now substantial and precise evidence for a general drive in a number of animals, and this can be looked upon as an indication of a primary motivation which to some extent, however slight, is superior to the governing centres of any of the instincts or of their combinations, and finds its most characteristic expression in exploratory behaviour in all its various forms'. [41]
In his monograph on "The Nature of Explanation" (1943), which has inspired a great many neurologists and computer-theorists, the Cambridge psychologist K. J. Craik put forward the idea that the function of the organism's nervous system is to set up a symbolic model of the external world: 'The brain . . . imitates or models external processes. The function of such symbolization is plain. If the organism carries a "small-scale model" of external reality and of its own possible actions within its head, it is able to try out various alternatives, conclude which is the best of them, react to future situations before they arise, utilize the knowledge of past events in dealing with the present and future, and every way to react in a much fuller, safer, and more competent manner to the emergencies which face it.' [42]
To extract information from the chaotic environment is as vital to the organism as it is essential for it to extract specific forms of energy from sunlight and food. If we assume this to be an inherent tendency of all living organisms, then we must also assume the existence of an inherent primary drive to explore the environment for relevant information.
Thus the organism functions not merely by responding to the environment, but by asking it questions. The main incentive to its exploratory activities are novelty, surprise, conflict, uncertainty.* The exploratory drive may combine with, or be instrumental to, other drives -- sex, nutrition, anxiety. But in its purest form -- in play, latent learning, unrewarded problem-solving -- 'stimuli' and 'responses' are undistinguishable parts of the same feedback loop along which excitation is running in a circle like a kitten chasing its tail. 'The scientist', wrote Allport, 'by the very nature of his commitment, creates more and more questions, never fewer. Indeed the measure of our intellectual maturity, one philosopher suggests, is our capacity to feel less and less satisfied with our answers to better problems.' [43]
We have thus established a broader base for the scientist's motivation as discussed earlier on (Book One, XI). The exploratory drive may combine with the self-transcending mysticism of a Kepler or with the self-asserting vanity of a Galileo. Each original artist has an element of the explorer in him: the poet does not 'manipulate words' as Watson thought, he explores the emotive and descriptive potentialities of language; the painter is engaged, throughout his life, in learning to see.
NOTES
To p. 496. Ernest Jones says in his biography: 'Freud partook in much of the prudishness of his time, when allusions to lower limbs were improper'. He then gives several examples -- such as Freud 'sternly forbidding' his fiancée to stay 'with an old friend, recently married, who, as she delicately put it, "had married before her wedding" ' (Jones, 1953, Vol. I, p. 142).
To p. 498. 'The simple reflex is probably a purely abstract conception, because all parts of the nervous system are connected together and no part of it is probably ever capable of reaction without affecting and being affected by various other parts . . . the simple reflex is a convenient, if not a probable, fiction' (Sherrington, 1906, p. 8).
To p. 500. 'His thinking was particular, not general. When he thought of secondary drive, he thought of . . . fear or anxiety. When he thought of secondary reinforcement, he thought of such things as . . . tokens substituting for food' (Hilgard, 1958, p. 177).
To p. 507. Uncertainty is more arousing than certainty -- as witnessed by the universal passion for gambling which coincided with the consolidation of the British Welfare State. Its rudiments can be found even in the rat and pigeon -- as Skinner himself pointed out -- when rewards are given rarely and irregularly; this treatment induces the creature to go on trying for an astonishingly long time without a single reward -- just as Britons will fill in week after week their football coupons.
IX
PLAYING AND PRETENDING
Logically every book on learning theory ought to have between the sections on 'innate behaviour' and 'acquired behaviour' a chapter on 'learning through play' -- or, at least, on 'ludic behaviour' (from ludere, to play) -- a term coined by Berlyne, presumably to make the subject sound more respectable. The role of play in the learning and practice of skills is too obvious to naturalists and pedagogues to need stre
ssing; yet play was another stepchild of the Psychology of the Dark Ages. Its connotations of curiosity, exploration, frivolousness and joie de vivre did not appeal to the spirit of the times; its unpredictability did not fit the S.-R. schema; above all, its self-reinforcing motivation, dissociated from the primary physiological needs, stood in flagrant contradiction to any drive-reducing theory. Thus the concept of 'ludic behaviour' was objectionable on the same grounds as the concept of the exploratory drive; the former appears in fact to be the purest manifestation of the latter.
Difficulties of Definition
A further reason for this neglect may have been the difficulty of defining 'play'* without making the definition circular. By way of elimination, let us try to distinguish between true play and vacuum activities during maturation. A young bird toys with straws and feathers 'aimlessly' before the other action-patterns of the nest-building instinct have matured; displays of fragmentary mating behaviour before sexual maturity fall into the same category. Some of these activities look playful in the sense of serving no apparent purpose (although in fact they may be useful as 'practice runs' in develop ing a skill); yet they can hardly be regarded as true play because they display all the rigidity of fixed action-patterns. They are performances of isolated bits of the animal's built-in repertory, and thus contrary to appearances, in the direct service of 'primary biological needs' in the classic sense. This implies that 'true play' is dissociated from those needs; that 'it does not have a biological function that we easily recognize'. [1] But precisely at this point the danger of circular definitions comes in: to say that play does not serve a primary need reopens the whole question of what needs, drives, motivations, should be called 'primary'. Thus, for instance, in Drever's Dictionary of Psychology play is defined as an 'activity, which may be physical or mental, existing apparently for its own sake, or having for the individual as its main aim the pleasure which the activity itself yields; usually involving also a detachment from serious aims and ends. . .' If we then ask 'What are serious aims and ends?' the answer is obviously: those which are not playful. The way out of the vicious circle is to 'take play seriously', as an activity with a definite 'primary biological function' -- viz. to give free rein to the exploratory drive. But such a view can only be held once it is recognized that the exploratory drive itself originates in a 'primary need' equal in importance to the others.
The Act of Creation Page 60