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

by James Sully

It is not difficult to surmise why the liberated energy should follow this particular nervous route. There is no doubt that the motor apparatus, by the disturbances of which all such interruptions of the smooth flow of respiration are brought about, is very readily acted on by emotional agencies. Altered respiration, showing itself in altered vocalisation, is one of the first of the commonly recognised signs of emotional agitation; and this effect has been rendered more clear and precise by recent experiments. We should expect, then, that the collapse of strained attitudes, with the great change in feeling-tone which this must carry with it, would deeply affect the respiration. We know, however, more than this. Severe efforts of attention are in general accompanied by a partial checking of respiration, an effect which seems to be alluded to in the French expression, an effort “de longue haleine”. On the other hand, the termination of such an effort is apt to be announced by the sigh of relief. Now, though the movements of laughter are not the same as those of sighing, they resemble the latter in their initial stage, that of deepened inspiration. May we not conclude, then, that laughter is likely to occur as another mode of physiological relief from the attitude of mental strain? And supposing, as seems certain, that laughter in its moderate degrees, by bringing a new briskness into the circulation, relieves the congested capillaries of the brain, may we not go farther and say that nature has {70} probably come to our aid by connecting with the mental upheavals and the cruel strains here referred to, which pretty certainly involve a risky condition of the cerebral system of capillaries, a mode of muscular reaction which is peculiarly well fitted to bring the needed relief?

More special conditions may favour the movements of laughter in certain cases. As I have observed above, Darwin suggests that the rapid alternation of crying and laughing which occur among hysterical patients may be favoured by “the close similarity of the spasmodic movements”.[49] In other words, the motor centres engaged, when in the full swing of one mode of action, may readily pass to the other and partially similar action. This would help to account for the short outbursts of laughter during a prolonged state of painful agitation, and to explain the fact noted by Descartes, that no cause so readily disposes us to laughter as a feeling of sadness.[50]

Our theory plainly requires that these sudden breakdowns or relaxations of strained mental attitudes should, even when only momentary interruptions, be accompanied by an agreeable sense of relief. I believe that those whose experience best qualifies them to judge will say that this is so. The dead weight of the fear, the poignancy of the grief, and the constraining effect of the situation of gêne, seem to yield at the moment when the “awful laugh” is snatched at. This comforting sense of a lightened load, though in part the direct result of a cessation of cerebral strain, would, as we have seen, pretty certainly derive added volume from the returning sense-reports telling of the ameliorated condition of the bodily organs.

3. We have considered two of the varieties of laughter {71} which lie outside the region of our everyday mirth. We may now pass into this region, and inquire, first of all, into the causes of those varieties which come under the head of joyous laughter.

Here we shall best begin by touching on the simple and early form which may be called the overflow of good spirits. Darwin, as has been mentioned, rightly regards the full reaction of the laugh as the universal expression by our species of good spirits, of a joyous state of mind. We have now to examine the mode of production of this simple type.

It is important to note that all experiences of pleasure do not bring on laughter. There are quiet enjoyments of a soothing character which are far from generating the powerful impulse needed for the movements of diaphragm and rib. To lie on a summer day in a hammock in a wood and indulge in the sweets of dolce far niente is to be out of reach of the tickling imp. States of enjoyment, too, which, though exciting, require a measure of close attention, such as those occasioned by a glorious sunset, or stirring music, do not start the spasmodic contractions of muscle.

The enjoyment that moves us to laughter must, it is evident, amount to gladness or joy. And this means, first of all, that the pleasurable consciousness must come in the form of a large accession, and, for a moment at least, be ample, filling soul and body. As the expression “good spirits” suggests, the organic processes during such states of joyousness are voluminous and well marked. As a part of this heightened tide of vital activity, we have the characteristic motor expression of the gladsome mind, the movement of the limbs, the shouting and the laughing.

Not all risings of the vital tide, however, produce laughter. Gentle and gradual augmentations of the sense of well-being {72} and happiness hardly tend to stir the muscles concerned. The joyous outburst marks a sudden accession of happy consciousness. It has something of the character of a violent flooding of the spirit and the corresponding bodily conduits.

There is a negative condition, also, to which it may not be superfluous to allude. The flood-like rise of the happy mood which is to produce laughter must not be accompanied by any further demand on the attention. A girl reading a first love letter from the man whom her heart has chosen will be glad, and will grow gladder by leaps and bounds. But the fulness of laughter will not come while unread words still claim the eye.

The laughter of joy is most noticeable, I think, under two sets of conditions. Of these the first is the situation of release from external restraint. The wild jubilant gladness of boys as they rush out of school, provided that they have the requisite reserve fund of animal spirits, is the stock example of this sort of laughter. The explosion seems here to be a way of throwing off the constraint and the dulness of the classroom, and getting a deep breath of the delicious sense of restored liberty. So far as the outflow of good spirits is thus connected with an escape from a serious and difficult attitude—strenuous application of the energies of mind and body in work—it is plainly analogous to the nervous laughter already considered.