An Essay on Laughter: Its Forms, Its Causes, Its Development and Its Value

by James Sully

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.