CHAPTER VI.

THE ORIGIN OF LAUGHTER.

To attempt to get back to the beginnings of human laughter may well seem to be too ambitious a proceeding. Beginnings are small things, and may easily escape detection, even when they lie well-lit not far from the eye. How, then, can we hope to get at them when they are hidden in the darkness of the remote past?

It is evident that our method here can only be the modest one of conjecture, a method which must do its best to make its conjecture look reasonable, while it never loses sight of the fact that it is dealing with the conjectural. Our aim is to get an intelligible supposition, by the help of which we may explain how laughter broke on the earthly scene, adding one more to the many strange sounds of the animal world.

This bit of conjectural inquiry will begin by trying to answer the question: By what process did the laugh, from being a general sign of pleasure, become specialised into an expression of the uprising of the mirthful, fun-loving or jocose spirit? It will then address itself to the problem: What has been the course of development of the spirit of fun and of its characteristic mode of utterance?

It would not, of course, be possible to attempt even a conjectural account of these far-off and unchronicled events, but for the new instruments of hypothetical construction {156} with which the Theory of Evolution has furnished us. In attempting so hazardous a task we have, at least, the example of one of the most modest of men to draw us on. Charles Darwin has taught us how to be at once daring and cautious in trying to penetrate the darkness of the ages behind us; and one can wish nothing better than to be able to walk worthily in his steps.

It will be evident that in essaying an effort which can at best end in only a plausible guess we must use every available clue. This means, not merely that we try to trace back the history of mirthful utterance, alike in the evolution of the individual and of the species, to its rude inchoate forms, but that we search for vestiges of utterances vaguely resembling human laughter in the animal world.

This last suggestion may well seem to the reader like another blow to man’s early pride of race. The worthy naturalist who called his species the “laughing animal” did not probably trouble himself about the question of the dignity of the attribute. Since laughing was one of the things that only man could do, it served as a convenient way of describing him. Yet, since the later evolutional psychology has led us to be more generous in recognising in the lower animals something closely similar to our own processes of reasoning, we need not be greatly shocked to hear that it is actually crediting other species than our own with a simple sense of fun, and a characteristic manner of expressing the feeling; that is to say, an utterance answering to our laugh.

Now here, if anywhere, we must be on our guard. In attempting to detect traces of mirthful expression in animals we are exposed to a two-fold danger: that common to all observation of animal ways—a too anthropomorphic kind of interpretation; and that of mistaking in other beings, {157} whether human or sub-human, what we envisage as funny, for their conscious fun. It is eminently natural, when we do not screw ourselves up to the severely scientific attitude, to see signs of chuckling glee in animals. I remember how I watched somewhere in Norway, in the early morning, a magpie as he stood for some time ducking his head and throwing up his long tail, accompanying these movements with chuckle-like sounds; and how I found it exceedingly hard not to believe that he was having a good laugh at something, possibly the absurd ways of the foreign tourists who visit his coast. Yet, judged by the standard of scientific observation, this “natural” interpretation was scarcely satisfactory.

Since our aim compels us to be scientific, we cannot accept common modes of interpreting the “mischievous” performances of animals. Many of a monkey’s tricks are “funny” enough; yet we may seriously doubt whether he enjoys them as practical jokes. His solemn mien certainly does not suggest it; but then it may be said that human jokers have a way of keeping up an appearance of gravity. A consideration of greater weight is that what looks to us much like a merry joke may be a display of the _teasing_ instinct, when this goes beyond the playful limit, and aims at real annoyance or mischief. The remark probably applies to some of the well-known stories of “animal humour,” for example, that of Charles Dickens about the raven. This bird, it may be remembered, had to share the garden with a captive eagle. Having carefully measured the length of this formidable creature’s chain, he turned to good account the occasion of the giant’s sleep by stealing his dinner; and then, the rightful owner having presumably woke up, made an impudent display of eating the same just safely outside the {158} eagle’s “sphere of influence”. This doubtless showed some cunning, and something of spite; but it is not clear that it indicated an enjoyment of the fun of the thing.

That this teasing and playing of tricks by animals may now and again approach the human attitude of malicious mirthfulness is not improbable. A cat that “plays” with its captive mouse, half-pretending, as it seems, not to see the small thing’s hopeless attempt to “bolt,” may, perhaps, be enjoying something of the exultant chuckle of a human victor. So, too, some of the mischievous behaviour of a lively and imperfectly domesticated monkey, which a simple-minded sailor has brought to his mother by way of making her happy, may disclose a germ of the spirit of fun, of a malicious playfulness which is capable of enjoying its jokes as such.

Yet, while we may question the truth of the proposition that these mischievous actions are enjoyed as practical jokes—in the way in which Uncle Remus represents them—we need not hesitate to attribute to animals a simple form of the child’s sense of fun. This trait appears most plainly in the pastimes of the young of many familiar species, including our two domestic pets, pastimes which are quite correctly described as animal play. The particular forms of this playful activity, the tusslings, the attacks and retreats on both sides, the chasings and the rest, are pretty certainly determined by special instincts.[89] But, as play, these actions are an expression of high spirits and of something analogous to a child’s love of “pretending”. Is it not a bit of playful make-believe, for example, when a dog, on seeing the approach of a canine stranger, “lies low” wearing the look of an alert foe; yet, as soon as the stranger approaches, “gives {159} away the show” by entering with an almost disgraceful celerity into perfectly friendly relations with him? It is the same when a dog teases another dog by startling him, showing signs of enjoying the trick. H. M. Stanley writes: “My dog took the same delight in coming up quietly behind a small dog and giving a terrifying bark as does the child in jumping out from a corner and crying ‘boo’”.[90]

Owing, to no little extent, perhaps, to the fact of its education by man, the dog gives much the clearest indications of a sense of fun. No one can observe a dog during a walk with his child-comrades without noting how readily he falls in with their playful proposals. The infectiousness of an announcement of the playful temper is clearly illustrated here. The dog imitates the gambols, and will even seem to respond to the vocal outbursts of his merry playmates. Darwin has rightly recognised a germ of our “sense of humour” in a dog’s joining in the game of stick-throwing. You throw a bit of stick for him to fetch, and having picked it up he proceeds to carry it away some distance and to squat down with it on the ground just before him. You then come quite close as if to take the stick from him, on which he seizes it and bears it off exultingly, repeating the little make-believe with evident enjoyment.[91]

I have tested a dog again and again when playing with him in this fashion, and have satisfied myself that he is in the play-mood, and knows perfectly well that you are too; so that if you pretend to be serious and to command him in your most magisterial voice to give up the stick he sidles up with a hollow show of obedience which could impose on nobody, as if to say, “I know better: you are not really serious; so I am going on with the game”. All {160} the notes of a true sense of fun seem to be present in this case: the gay and festive mood, a firm resolve _desipere in loco_, and a strong inclination to play at “pretending”.

Prof. Lloyd Morgan gives an example of what certainly looks like a dog’s merry make-believe in which man’s lead takes no part. The writer tells us that he used at one time to take an intelligent retriever to a sandy shore, where the dog engaged spontaneously in the following pastime. He buried a number of small crabs in the sand, and then stood waiting till a leg or a claw appeared, “upon which he would run backwards and forwards giving short barks of keen enjoyment”.[92]

I find it hard to doubt that this was a genuine outburst of joyousness and of something indistinguishable from a love of fun, and that it was connected with the “coming off” of a practical joke. The repetitions of the burial when the dog had seen that it was ineffectual, points clearly to a consciousness of the make-believe character of the performance.

Whatever a dog’s powers of jocosity when uninstructed by man, it seems safe to set down a good share of his highly developed sense of fun to his profound susceptibility to man’s educative influence; which again (as the difference between the educability of the dog and of the cat at once shows) implies an unusual strength of those instincts of attachment to man which have made him almost the type of fidelity.

How far, one wonders, will this educative influence of man be likely to go in the case of the most companionable of our domestic pets? W. Preyer tells us, that the dog is capable of imitating the signs of human gaiety, that an {161} intelligent specimen, when confronted with our laughter will draw back the corners of his mouth and leap into the air with a bright lustre in the eye.[93] Here we seem to have a rudiment of a genuine laugh, and may perhaps cease to speak rather confusingly of a dog’s “laughing with his tail”. G. J. Romanes relates that he had a dog who went some way towards qualifying himself for the office of clown. This animal would perform a number of self-taught tricks which were clearly intended to excite laughter. “For instance, while lying on his side and violently grinning, he would hold one leg in his mouth.” Under these circumstances “nothing pleased him so much as having his joke duly appreciated, while, if no notice was taken of him, he would become sulky”.[94]

This animal must, one supposes, have been in an exceptional degree a “funny dog”. It seems a pity that the observer did not take a “snapshot” at that grin so that it might be a shade less abstract and “in the air” than the grin of the Cheshire cat, as treated by Mr. Lewis Carroll. What seems clear is, that the physiognomy of a dog manages to execute a weirdly distorted semblance of our smile. With respect to the vocal part of the expression, we must not expect too much. The bark may not be able to adjust itself to our quick explosions of gaiety. It is commonly said that the dog has a special bark for expressing pleasure, and it seems likely that he employs this when he is said to be seized by the sense of the funniness of things.

On the moral side, the possibility of the dog’s becoming a humorous beast looks more promising. He certainly exhibits rudiments of feelings and mental attitudes which {162} seem in man to be closely related to a reflective humour. As the inner circle of his human friends know, he can be terribly bored. I saw, not long since, a small dog undergoing the process of chaining by his mistress before she took him into a shop. He drew a long yawn, and his appearance was eminently suggestive of a keen sense of the absurdity of the shopping habits of ladies, a sense which only wanted the appropriate utterance to become a mild, tolerant kind of satire. Yet one must be mindful of one’s own warning against a too hasty interpretation of such actions.

We may now turn to animals much nearer ourselves in the zoological scale. Among monkeys we obtain, undoubtedly, something more closely akin to our smile and laugh. Darwin has made a careful inquiry into the similarities between the two. He tells us that some of the essential features of the facial expression during a laugh, the drawing backwards of the corners of the mouth, the formation of wrinkles under the eyes, etc., are “characteristic and expressive of a pleased state of mind in various kinds of monkeys”.[95]

With respect to laughter-like sounds, Darwin gives us several pertinent facts. A young chimpanzee will make a kind of barking noise when he is pleased by the return of any one to whom he is attached, a noise which the keeper interprets as a laugh. The correctness of this interpretation is confirmed by the fact that other monkeys utter a kind of “tittering sound” when they see a beloved person. A young chimpanzee when tickled under the armpits produces a more decided chuckling or laughing sound. “Young ourangs, also, when tickled will make a chuckling sound and put on a grin.”

It has been found by Dr. L. Robinson that the young of {163} the anthropoid apes are specially ticklish in the regions of the surface of the body which correspond with the ticklish regions in the case of the child. Not only so, a young chimpanzee will show great pleasure when tickled, rolling over on his back and abandoning himself to the pastime, much as a child does. When the tickling is prolonged he resembles a child further by defending ticklish spots. So, too, does a young ourang. It may be added that young apes, like many children, make a pretence of biting when tickled.

To sum up: the young of the higher apes have something resembling our smile and laugh, and produce the requisite movements when pleased. Their attempt at laughter, as we might be disposed to regard it, appears as a sign of sudden joy in circumstances in which a child will laugh, _e.g._, on the reappearance of a beloved companion after a considerable interval. It further occurs when the animal is tickled, along with other manifestations which point to the existence of a rudiment of the child’s capacity for fun and for the make-believe of play.

One more fact should be added in order to bring out the similarity here to the human attitude towards the laughable. It is probable, from the testimony of several observers, that monkeys dislike being laughed at.[96] Now, it is true that the enjoyment of fun and the dislike to being made its object are not the same thing. Nor do they seem to vary together in the case of men; otherwise the agelast would not be so often found among those who keenly resent being the object of others’ laughter. Nevertheless, they may be regarded in general as correlative traits; creatures which show a distinct distaste for being made the objects of laughter may be supposed to be capable of {164} the laughing attitude, so far at least as to be able to understand it.

Turning now from sub-human kinds of laughter to the full expression as we know it in ourselves, we may briefly trace the history of the smile and laugh during the first years of life. Here the question of the date of the first appearance of these expressive movements becomes important; and happily we have more than one set of careful observations on the point.

With respect to the smile, which is commonly supposed to be the first to show itself, we have notes made by Darwin and by Preyer. According to the former, the first smile appeared, in the case of two of his children, at the age of forty-five days, and, of a third, at a somewhat earlier date.[97] Not only were the corners of the mouth drawn back, but the eyes brightened and the eyelids slightly closed. Darwin adds that the circumstances pointed to a happy state of mind. Preyer is much fuller here.[98] He points out the difficulties of noting the first true smile of pleasure. In the case of his own boy, it seems, the movements of the corners of the mouth, accompanied by the formation of dimples in the cheek, occurred in the second week, both in the waking and in the sleeping state. The father thinks, however, that the first smile of pleasure occurred on the twenty-sixth day, when after a good meal the child’s eyes lighted on the mother’s face. This early smile, he adds, was not an imitation of another’s; nor did it imply a joyous recognition of the mother. It was just the instinctive expression of a feeling of bodily satisfaction. {165}

Other observers differ, too, in respect of the date of the first occurrence of the true expressive smile. For example, Dr. Champneys puts it in the sixth, Sigismund in the seventh week, agreeing roughly with Darwin; whereas Miss Shinn gives as the date the latter half of the first month, and so supports Preyer’s observations. Another lady, Mrs. K. C. Moore, would go farther than Preyer and say that the first smile occurs on the sixth day of life.[99] It may be added that Miss Shinn is more precise than Preyer in her account of the early development of the smile. She tells us that, whereas the first smile of her niece—whom we will henceforth call by her name, Ruth—(latter half of first month) was merely the outcome of general comfort, a smile occurred in the second month which involved an agreeable perception, namely, that of faces bending over the child in which she took great interest. This smile of special pleasure, expressing much gaiety, occurred when she was lying fed, warm, and altogether comfortable.

It is fairly certain that these differences indicate some inequalities of precocity in the children observed. At the same time, it seems probable that the several observers are dealing with different stages in the development of the smile. Preyer shows clearly that it undergoes considerable expansion, involving increased complexity of movement, and the addition of the important feature, the brightening of the eye. Mrs. Moore gives no description of what she saw on the sixth and seventh days, and is presumably referring to a vague resemblance to a rudiment of a smile which had no {166} expressive significance; and some things in Preyer’s account lead us to infer that he is speaking of a less highly developed smile than Darwin.[100]

All that can certainly be said, then, is that the movements of a smile, as an expression of pleasure, undergo a gradual process of development, and that an approach to a perfect smile of pleasure occurs some time in the second month of life.

If we turn to the dates assigned to the first occurrence of a laugh, we find the uncertainties are at least equal to those encountered in the case of the smile. Darwin illustrates how a smile may gradually take on an accompaniment of sound which grows more and more laughter-like. One of his children, who, he thinks, first smiled at the age of forty-five days, developed about eight days later a more distinct and impressive smile, accompanied by a little “bleating” noise, which, he adds, “perhaps represented a laugh”. It was not, however, till much later (113th day) that the noises became broken up into the discrete sounds of a laugh. Another child of his, when sixty-five days old, accompanied his smile by “noises very like laughter”. A laughter, with all the indications of genuine fun behind it, occurred in the case of one of his children on the 110th day, when the game was tried of throwing a pinafore over the child’s face and then suddenly withdrawing it, this being varied by the father’s suddenly uncovering his own face and approaching the child’s. He adds that, some three or four weeks before this, his boy appeared to enjoy as a good joke a little pinch on his nose and cheeks.

Preyer puts the date of the first laughter-like sounds, as {167} he puts that of the first smile, earlier than Darwin. He says he observed a visible and audible laugh in his boy on the twenty-third day. This was a chuckling at the view of a rose-tinted curtain. The sounds were repeated in the following weeks at the sight of slowly swinging coloured objects and at new sounds, _e.g._, those of the piano. At the same time he tells us that a prolonged loud laughter, recognisable as such by a person not looking at what was going on, first occurred in the eighth month when the boy was playing with his mother. Among the other observers it may suffice to refer to one of the most careful, Miss Shinn. This lady, who, it will be remembered, puts the date of Ruth’s first smile as early as the first month, assigns the child’s first genuine laughter to the 118th day. It was excited by the sight of the mother making faces. It is worth adding that Ruth reached her third performance eleven days later.[101]

In this case, too, it is probable that we have to do, not merely with differences of precocity in the children observed, but with the difficulties of determining what is a clear example of the expression concerned.[102] There is no doubt that the full reiteration of our laughter is reached by stages. This is brought out fully by Darwin, and is allowed by Preyer. Yet how much of the series of more or less laughter-like sounds produced by an infant during states of pleasure is to be regarded as entering into the development of laughter, it is not easy to say. Miss Shinn heard Ruth give out curious little chuckling sounds of two syllables on the 105th day, that is thirteen days before she produced her {168} laugh. She adds under the date, 113th day, that is to say, five days before the laugh, that the child had developed new throat sounds, crowing, croaking, etc., and showed a strong disposition to vary sounds in a pleasurable mood. It seems highly improbable that these sounds were not preparatory stages in the development of the laugh.[103]

It is fairly certain that laughing comes after smiling. Preyer’s words may no doubt seem to suggest that the first laugh (twenty-third day) comes before the first smile (twenty-sixth day); but his account of the development of the two shows plainly that this is not his meaning. He distinctly says that laughter is only a strengthened and audible (laut) smile; and remarks, further, that “in all (children) alike the utterance of pleasure begins with a scarcely noticeable smile, which quite gradually passes into laughter in the course of the first three months”. He adds that this development depends on that of the higher brain centres, and the capability of having perceptions.[104]

The first laughter is, like the smile, an expression of pleasure. As Preyer puts it, the laughter is a mere heightening of the look of pleasure. It marks, however, a higher level of agreeable consciousness. Whereas the first clumsy experiments in smiling denote nothing but a comfortable state of repletion, the first attempts at laughter are responses to gladdening sense-presentations, such as swinging coloured objects, and the new sounds of a piano. This laughter at new visual and aural presentations was followed, according to Preyer, between the sixth and the {169} ninth week by a laughter more distinctly joyous or jubilant, as the child regarded his mother’s face and appeared to recognise it. This laughter of mental gaiety seems at an early age—about the fourth month—to ally itself with movements of the limbs (raising and lowering of the arms, etc.) as a complex sign of high spirits or gladness.[105]

How far the provocative of laughter mentioned by Darwin, namely, suddenly uncovering the child’s head (or his own) implied a rudiment of fun, I am not sure. It shows, however, the early connection between laughter and agreeable surprise, that is to say, a mild shock, which, though it borders on the alarming, is on the whole gladdening.

One other early form of laughter, which is found also in certain young animals, is that excited by tickling. This has been first observed, in the case of the child, in the second or the third month. Preyer’s boy laughed in response to tickling in the second month.[106] Dr. Leonard Hill tells me that his little girl, who was by-the-bye specially sensitive to titillation, responded first by laughter in the tenth week.

Since our analysis has led us to regard the effect of tickling as largely mental, and as involving a playful attitude, this fact confirms the conclusion that the specialised laughter which is the accompaniment of play occurs in a well-defined form within the first three months.

To sum up: We find, within the first two or three months, both the smile and the laugh as expressions of pleasure, including sensations of bodily comfort and gladdening sense-presentations. We find, further, in the reflex reaction of laughter under tickling, which is observable about the {170} end of the second month, the germ of a sense of fun, or of mirthful play; and this is indicated too in the laughter excited by little pinches on the cheek at the end of the third month.

It is certain that these tendencies are not learned by imitation. This is proved by the fact, established by Preyer, that imitative movements do not occur in the normal child till considerably later, and by the fact that the child, Laura Bridgman, who was shut out by her blindness and deafness from the lead of companions, developed these expressions. We must conclude, then, that they are inherited tendencies.

Here the psychologist might well stop in his inquiries, if Darwin and others had not opened up the larger vista of the evolution of the species. Can we, by carrying the eye along this vista, conjecture how these instinctive movements came to be acquired in the course of animal evolution?

The first question that arises in this inquiry is whether the smile or the laugh was the earlier to appear in the course of racial development. The expressions of animals below man do not offer any decisive clue here. The anthropoid apes appear both to produce a kind of smile or grin, and to utter sounds analogous to our laughter. It may, however, be contended that this so-called laughter is much less like our laughter than the grin is like our smile. In the absence of better evidence, the fact that the smile appears first in the life of the child must, according to a well-known law of evolution, be taken as favouring the hypothesis that man’s remote ancestors learned to smile before they could rise to the achievement of the laugh. This is further supported by the fact that, in the case of the individual, the laugh when it occurs announces a higher form of pleasurable consciousness, the level of perception {171} as distinguished from the level of sensation which is expressed by the first smile. Lastly, I am informed that among imbeciles the smile persists lower down in the scale of degeneration than the laugh. Dr. F. E. Beddard writes to me: “I remember once seeing a defective human monster (with no frontal lobes) whose only sign of intelligence was drawing up the lips when music was played”.[107]

It is commonly held that, since the expression of pain, suffering, or apprehension of danger among animals is a much more pressing necessity for purposes of family and tribal preservation than that of pleasure or contentment, the former is developed considerably earlier than the latter. According to this view, we can understand why the adumbrations of a smile and a laugh which we find in animals closely related to man have been so imperfectly developed and appear only sporadically.

Supposing that the smile was the first of the two expressive movements to appear in the evolution of the human species, can we conjecture how it came to be the common and best-defined expression of pleasurable states? In dealing with this point we may derive more definite aid from Darwin’s principles.

The fact that the basis of a smile is a movement of the mouth at once suggests a connection with the primal source of human as of animal enjoyment; and there seems, moreover, to be some evidence of the existence of such a connection. A baby after a good meal will, I believe, go on performing something resembling sucking movements. The first smiles may have arisen as a special modification of these movements when there was a particularly lively feeling of organic contentment or well-being. I believe, further, {172} that an infant is apt to carry out movements of the mouth when food is shown to it. A similar tendency seems to be illustrated by the behaviour of a monkey which, when a choice delicacy was given it at meal-time, slightly raised the corners of the mouth, the movement partaking of the nature of “an incipient smile”.[108] Again, our hypothesis finds some support in the fact that, according to Preyer and others, the first smiles of infants were noticed during a happy condition of repletion after a good meal.[109]

Supposing the smile in its origin to have thus been organically connected with the pleasurable experience of sated appetite, we can easily see how it might get generalised into a common sign of pleasure. Darwin and Wundt have made us familiar with the principle that expressive movements may be transferred to states of feeling resembling those of which they were primarily the manifestations. The scratching of the head during a state of mental irritation is a well-known instance of the transference.

There are, I believe, facts which go some way towards verifying the supposition of a transference of eating-signs to states of lively satisfaction and pleasure generally. Savages are wont to express keen pleasure by gestures, _e.g._, rubbing the belly, which seem to point to the voluminous satisfactions of the primal appetite. The clearest evidence, however, seems to be furnished by the account of a baboon given us by Darwin. This creature, after having been made furiously angry by his keeper, on making friends again, “rapidly moved up and down his jaws and lips and looked pleased”. {173} Darwin adds that a similar movement or quiver of the jaws may be observed in a man when he laughs heartily, though with us the muscles of the chest rather than those of the lips and jaws are “spasmodically affected”.[110]

Judging from the interval between the occurrence of the first smile and of the first laugh in the life of the individual, we may conjecture that laughter did not grow into a full reiterated sound in “primitive man,” or his unknown immediate predecessor, till much later. We should expect that a considerable development of vocal power would be a condition of man’s taking heartily to this mode of emotional utterance. The study of the infant certainly supports this idea. The babble of the second and third months, which is made up of a reiteration of many vocal and consonantal sounds, may prepare for laughter, as it certainly does for speech. The observations of Miss Shinn, quoted above, on the expansion of the range of vocal sound before the occurrence of the first laugh are most significant here. They seem to point to the fact that in the evolution of the species the first laughter was selected from among a great variety of sounds produced in pleasurable states.

Let us now suppose that our immediate animal ancestor has reached the level of clear perceptions, and is given to the utterance of certain reiterated sounds during states of pleasure. Let us further conceive of him as having his sympathies developed up to the point of requiring a medium for expressing not only pains but pleasures, and more particularly for calling others’ attention to the presence of cheering and welcome objects, _e.g._, of a member of the family who has been abroad for a time. Such an animal would need to improve on his primal smiles and grins. He would require vocal utterances of some strength in order {174} to reach distant ears, something answering to the cackle of the hen when she has discovered some choice morsel and desires to bring her brood to her side. How is this improvement to be effected?

One may hazard the guess that the process may have been something of this kind. The position of the open mouth during a broad smile was, we may reason, in itself favourable to the production of vocal sounds. We may, after the analogy of positions of the eyes, speak of it as the “primary position” of the vocal chamber when opened. This primary position would pretty certainly be specially favourable to the utterance of a certain kind of sound, let us say that commonly indicated by “eh,”[111] together with something of the guttural or chuckling accompaniment of this in the sound of laughter. We may then infer that, when some of the reiterated babble-like sounds were produced during states of pleasurable satisfaction, the same (primary) position would be taken up. We should thus get, as psycho-physical concomitants of the sensed position of the opened mouth during a broad smile or “grin,” not only a disposition to reiterate the “eh” or some similar sound as a completion of the whole action, of which the opening of the mouth is the first stage, but a definite associative co-ordination between the movement of opening the mouth and the reiterated actions of the muscles of the respiratory and vocal apparatus. In this way we may understand how, when the pleasurable state expressed by a smile increased in intensity, as, for example, when the happy feeling excited by the sight of a face passed into the joy of recognising a member of the family, the {175} movements would widen out into those of a laughter-like utterance.

It appears to me that, in this connection, the observed course of development of laughter in the individual is not without its suggestiveness. Miss Shinn remarks that Ruth’s mouth was opened wide on the 113th day—five days before the first laugh—while the child was tossed and tumbled. Under date of the 134th day, again, we read of much laughter of an inaudible kind, consisting of broad laughter-like smiles; and these observations certainly show that about the date of the first laughter an expanded smile, indistinguishable from a laugh save by the absence of the respiratory and vocal adjunct, was frequent. In other words, they tell us that about the time when she achieved her first laugh she was freely practising the intermediate facial step between the earlier smile and the true laugh.

This theory would plainly illustrate Mr. Herbert Spencer’s principle, that states of feeling affect the voluntary muscles in the order of increasing calibre, the smaller being called into play by feelings of lower intensity, the larger by those of higher intensity. But this theory is not enough. We must take into account also the order of frequency of use, and of consequent liability to discharge in the connected nerve-centres. It seems probable that the muscles engaged in the movements of the mouth and those exercised in phonation would, for these reasons, be specially liable to be acted upon. These wider tendencies would, according to the above hypothesis, be assisted by special associations. These would secure the combination of the two groups of movements, which I have assumed to have been employed independently as utterances of pleasurable feeling: namely, those involved in smiling, and those underlying the first happy reiterated sounds of a quasi-infantile babbling. {176}

One element in the laugh, its explosive vigour, seems unaccounted for on this hypothesis. Here, I think, the effect of relief from strain, which is so common a factor in human laughter, may be called in. The earliest laughter of the child seems to illustrate this element. For example, that which occurs during tickling, in a game of bo-peep, and at the sight of the mother making faces may be said to arise from a serious attitude suddenly dissolved. Perhaps the first great laugh was produced by man or by his proximate progenitor, when relief came after fear or the strain of battle. So far as primitive laughter was the outcome of such concentrated energy seeking relief, this circumstance would help to account for the prolongation as well as for the strength of the sounds.

Our conjecture cannot lay claim to be a hypothesis. It makes no attempt to explain the precise forms of the changes which enter both into the smile and into the laugh. At best, it is only a rough hint as to a possible mode of genesis.

I have here treated of the genesis of laughter under its more general aspect as an expression of pleasurable states of feeling. We have seen, however, that within the first three months of life another and clearly specialised variety of laughter emerges, namely, that called forth by tickling. It follows from our analysis of the effect of tickling that it is one of the earliest manifestations, in a clear form, of the laughter of fun or of play. As such, it demands special attention in any attempt to explain the development of laughter.

As a specialised reaction having a clearly marked reflex form, it is natural to ask whether laughter in response to tickling is not inherited, and, if so, how it arose in the evolution of the race. And we find that suggestions have {177} been made for explaining the genesis of this curious phenomenon. We will first glance again at the facts, and then examine the hypotheses put forward for explaining them.

Here, again, the question how far animals are susceptible of the effect becomes important. I have already alluded to Darwin’s remark, that if a young chimpanzee is tickled, more particularly under the armpits, he responds by a kind of laughter. The sound is of a chuckling or laughing kind. The emission of these sounds is accompanied by retraction of the corners of the mouth, and sometimes by a slight amount of wrinkling in the lower eyelids.[112] Dr. Louis Robinson publishes other observations of the effect of tickling on the young of anthropoid apes. He tells us that a young chimpanzee when tickled for some time under the armpits would roll over on his back showing all his teeth and accompanying the simian grin by defensive movements, just as a child does. A young ourang at the Zoological Gardens (London) behaved in a very similar way. The young of other animals, too, betray some degree of ticklishness. Stanley Hall remarks that a dog will retract the corners of his mouth and thus go some way towards smiling if tickled over the ribs.[113] Dr. Robinson finds that horses and pigs are also ticklish; and he thinks that these animals have specially ticklish regions, which correspond to a considerable extent to those which have been ascertained in the case of the child.

We may now refer to the first appearances of the tickling reflex in the child. As pointed out above, the response by defensive movements appears shortly after birth, whereas {178} the earliest instance of a response by laughter occurs in the second, or in the first half of the third month. It is to be noted that this date is distinctly later than that of the first laughter of pleasure, though it is not far removed from that of the first clear appearance of the laughter of gaiety or jubilation.

These chronological facts bear out the theory that the laughter of a tickled child has a distinct _psychical_ antecedent. On this point Dr. L. Robinson writes to me as follows: “I have never been able to succeed in eliciting laughter from young infants under three months old by means of tickling, _unless one also smiled and caught their attention in some such way_”. This evidently points to the influence of mental agencies even in the first stages of laughter from tickling.

With respect to the parts in which the tickling first excites laughter, different observers appear to have reached dissimilar results. Preyer distinctly speaks of the tickling of the sole of the foot as provoking laughter in the second month. Whether he tried other parts he does not say. Dr. Leonard Hill tells me that one of his children first responded to tickling when the titillation attacked the palm of the hand, or ran up the arm. Responses to the tickling of the neck and soles of the feet came later.

The fact that the effect of tickling becomes so well defined by, or soon after, the end of the second month, proves pretty conclusively that it is an inherited reflex; and the evolutionist naturally asks what it means, what its significance has been in the life of our ancestors.

Dr. Stanley Hall carries back evolutional speculation very far, and suggests that in tickling we may have the oldest stratum of our psychic life, that it is a survival of a process in remote animal progenitors for which touch was the only {179} sense. He supposes that in these circumstances even light or “minimal” touches, say those coming from the movements of small parasites, being unannounced by sight or other far-reaching sense, would be accompanied by disproportionately strong reactions. He does not attempt to explain how laughter grew out of these reactions. He does indeed call them reactions “of escape,” but he does not follow up the idea by hinting that the violent shakings of the body by laughter, when it came, helped to get rid of the little pesterers. In truth, this ingenious thinker hardly appears to make the explanation of the laughter of tickling, as distinguished from the other reactions, the subject of a special inquiry.[114]

A more serious attempt to explain the evolution of the laughter of tickling has been made by Dr. Louis Robinson. He, too, hints at the vestigial survival of experiences of parasites, but appears to think that these account only for the disagreeable effects which are brought about when the hairy orifices of the nostril and the ear are tickled. This limitation strikes one as a little arbitrary. The reaction of laughter, which Dr. L. Hill called forth when he made his fingers run up the arm of his infant, is surely suggestive of a vestigial reflex handed down from ages of parasitic pestering.[115]

With regard to the laughing reaction, which, as we have seen, he considers to involve a distinct mode of stimulation, he suggests that it is an inherited form of that common mode of play among young animals, which consists in an exchange of good-natured and make-believe attacks and defences, or a sort of game of sham-fight. {180}

In support of this theory he lays stress on the fact that susceptibility to tickling is shared in by the young of a number of species of animals standing high in point of intelligence, including not only the higher apes, but the dog and the horse. He adds that, in general, there is a concomitance between the degree of playfulness of a young creature and that of its ticklishness, though lambs and kids which are not ticklish are allowed to be an awkward exception.

If tickling is a playing at fighting we may expect it, like other kinds of play, to mimic serious forms of assault. Now we know that the first rude attacks of man, so far as we can gather from the movements of a passionate infant, took the forms of striking, tearing with the nails and biting. Tickling may be said to be a sort of mild pretence at clawing. Dr. Robinson tells us that about 10 per cent. of the children he has examined pretended to bite when they were tickled, just as a puppy will do.

Dr. Robinson goes a step farther and seeks to show that the areas of the bodily surface which are specially ticklish in children are those likely to be attacked in serious warfare. In nearly all of them, he says, some important structure, such as a large artery, is close to the surface and would be liable to injury if the skin were penetrated. They would thus be highly vulnerable regions, and consequently those which would be singled out for attacks by teeth or claws. He argues that the same relation holds in the case of animals which attack one another in the same way as man. The regions of special ticklishness in their case, too, appear to correspond, roughly at least, with vulnerable regions. Indeed, in the young chimpanzee and the young ourang these ticklish areas are approximately the same as in the child. {181}

From all this he concludes that ticklishness, being bound up with the mimic warfare which fills so large a space in the life of many young animals, has its utility. The strong liking to be tickled, which children and, apparently, some other young animals express, serves, in combination with the playful impulse to carry out this gentle mode of attack, to develop mimic attacks and defences which are of high value as training for the later and serious warfare.

These applications of the evolution theory are certainly interesting and promising. I think the idea of relief from parasites might be worked out further. May it not be that the light touches given by the fingers of the parent, or other member of the ancestral family when hunting for parasites on the surface of the young animal, have, by association with the effects of relief from the troublesome visitors, developed an agreeable feeling-tone? As we have seen, the laughter of tickling has a distinctly mental antecedent; it appears in the child, only when he is beginning to enjoy laughingly little pinches on the cheek, and otherwise to show a germ of a sense of fun. The light touches, reminiscent at once of unpleasant settlers, and of delivering fingers, would, one imagines, be exactly fitted to supply that dissolution into nothing of momentary apprehension indicated by our analysis of the mental factor in tickling.

With respect to Dr. Robinson’s hypothesis, it may be acknowledged ungrudgingly to be a brilliant piece of hypothetical construction. But, as the writer frankly confesses, the facts, here and there, do not point in its direction. A very serious objection is the fact that the sole of the foot and the palm of the hand are not taken into account in his attempt to establish a correspondence between the ticklish areas of {182} the surface and a high degree of vulnerability. In Stanley Hall’s returns it is the sole of the foot which is most frequently mentioned as a ticklish area; and, as we have seen, it was the first to give rise to laughter in the case of one child at least.[116]

There is another and more serious objection to Dr. Robinson’s theory as an explanation of laughter. One may urge that the occurrence of such violent movements would, by shaking the body and by inducing fatigue much earlier than need be, pretty certainly be detrimental to that prolonged practice of skill in attack and defence, to which Dr. Robinson attaches so much importance.

The supposition that tickling is a variety of play developed by natural selection among combative animals is, I think, highly probable. The play of animals, like that of children, is largely a form of social activity involving a playmate; and is apt, as we know, to take the form of attack and defence, as in chasing, throwing over, pretending to bite, etc. These playful attacks are, as we have seen, closely related to teasing; indeed, teasing may be viewed as merely a play-imitation of the first stage of combat, that of challenging or exciting to contest.[117] Tickling pretty obviously finds a fitting place among the simpler forms of playful combat which have a teasing-like character. Moreover, these forms of social play all seem to show, in a particularly clear manner, the utility referred to in the preceding chapter. {183}

Now, this idea will, I think, help us to understand how loud and prolonged laughter came to join itself to the combative game of tickling and being tickled. If play—pure, good-natured play—was to be developed out of teasing attacks, it would become a matter of the highest importance that it should be clearly understood to be such. This would mean, first of all, that the assailant made it clear that his aim was not serious attack, but its playful semblance; and secondly, that the attacked party expressed his readiness to accept the assault in good part as sport. It would be of the greatest consequence to the animal that chanced to be in the play-mood and wished to make overtures of friendly combat that he should be sure of an equally gamesome attitude in the recipient of the challenge. One may see this by watching what happens when a dog, unwisely trying to force a frolic on another dog, is met by a growl and possibly by an uncovering of the canine teeth. Now, what better sign of good-temper, of readiness to accept the attack as pure fun, could nature have invented than the laugh? The smile is, no doubt, a pretty good indicator in some circumstances. Yet one must remember that the rudimentary smile of an ape-like ancestor may, now and again, have been misleading, as our own smiles are apt to be. A laugh would presumably be less easy to affect in such circumstances than a smile; and, in any case, it would be far less liable to be overlooked.

In saying that the laughter which accompanies tickling and other closely allied forms of play in children owes its value to its being an admirable way of announcing the friendly playful mood, I do not mean that other signs are absent. Dr. L. Robinson reminds us that a tickled child will roll over on his back just like a puppy. The laughter and the rolling over seem to be two congenitally connected {184} modes of abandonment to the playful attack. In the young of other ticklish animals, _e.g._, the puppy, the rolling over may of itself suffice to give the friendly signal.

It seems not unlikely that this consideration, the utility of laughter as a guarantee to a playful challenger that his overtures will be received in the proper spirit, applies to the evolution of all laughter which enters into such forms of social play as the pretence to attack, to frighten, and generally what we call good-natured teasing. It has been suggested that teasing might well be taken as the starting-point in the evolution of play.[118] By adopting this idea, and by regarding laughter, in its elementary form, as essentially a feature of social play, we might set out with this consideration of utility in constructing our theory of the evolution of laughter. One is tempted, too, to follow this course by the fact, recognised in common language, that much, at least, of the later and more refined laughter is analogous to the effect of tickling.[119]

Nevertheless, as we have seen, the best evidence attainable points to the conclusion that this simple form of the laughter of social play was preceded by, and grew out of, a less specialised kind of laughter, that of sudden accession of pleasure. We may conjecture that the laughter provoked by tickling was reached in the evolution of our race soon after this reaction passed out of its primal and undifferentiated form as a general sign of pleasurable excitement, and began to be specialised as the expression of mental gaiety and of something like our hilarity. The fact, noted above, {185} that children only laugh in response to tickling when they are in a pleasurable state of mind seems to confirm the hypothesis that the love of fun, which is at the bottom of tickling and makes it perhaps the earliest clear instance of mirthful play with its element of make-believe, first emerged gradually out of a more general feeling of gladness.

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