One of its most obvious characteristics is its contagiousness, already referred to.[227] The potent appeal of laughter to a mechanical imitativeness is significant in more ways than one. It suggests how large a part of human hilarity is nothing but a kind of surface resonance, as empty of ideas as the infectious yawn or cough. But it suggests also that laughter is social in the sense that it is essentially choral and so uniting. A gathering of yokels at a fair laughing at a clown tends for the moment to become a coherent group; and the habit of laughing together will tend to consolidate the group. When the conjoint laughter is less automatic and issues from community of ideas and sentiments, the contagious property still plays a part. It is as if the swift response of others’ laughter, the drowning of one’s own outburst in the general roar, effaced for the time the boundaries of one’s personality. To rejoice together in the full utterance of the laugh, though it moves us less deeply than to weep together, is perhaps no less potent in cementing a lasting comradeship. The social side of laughter comprehends, however, much more than this. It is commonly recognised that the feeling expressed has something human for its object. Now those {256} who directly or indirectly serve as the butt are all the world over disposed, till the grace of a genial tolerance has been added, to dislike and resent the part thrust on them. So far, then, laughter would seem to be anti-social and dividing, and, alas, the history of literature will furnish the student with notable illustrations. Yet this hurtful edge in laughter becomes one of its valuable social properties. As the despised Greenlanders may teach us, laughter supplies a mode of punishment which combines with effectiveness, economy and humanity, a good deal of enjoyment for the onlookers. In all societies, if not exactly in the Greenland fashion, it has been accorded an important place among the agencies which, by castigating vices and follies, seek to lower their vitality. The sharp edge of laughter represents, however, only one of its effects on the sensibilities of the butt. Savage life has given us illustrations, not only of its disagreeable consequences turned to judicial purposes, but of its agreeable consequences in cajoling others out of attitudes of hostility and stubbornness. This curious effect, as it may seem, of a mode of treatment which is primarily hurtful is to be explained in the main by its playful function. To substitute a joke for argument or coercive pressure is, like tickling, to challenge to play, and tends to call up the play-mood in the recipient of the challenge. The mutual teasings of savages serve, as we have seen, as a training, an ἄσκησις, in simple and estimable virtues, such as the maintenance of good temper, toleration, and the setting of comradeship above one’s private feelings.