Surprise is connected with fear, and for this reason is in itself a disagreeable sensation; yet, on account of its strong psychophysical effect—namely, the shock which it produces—it becomes highly enjoyable in play, and displays, perhaps more clearly than any of the other cases, the charm of strong stimuli. Children indulge very early in play involving the shock of surprise, and its effectiveness as a means of giving pleasure becomes more and more intense. Darwin relates that his son, from the one hundred and tenth day, was wildly delighted when a handkerchief was laid over his face and then suddenly withdrawn, or when his father’s face was hidden and revealed in this way. “He then uttered a little noise, which was an incipient laugh.” I referred to this in speaking of expectancy, which, indeed, goes hand in hand with surprise, however opposed they may appear, since surprise which is entirely unexpected is of course no part of play. There is always playful experimentation with the shock when we expect it, but do not know when or in what form it will appear. It is just this combination which makes the emotional effect of surprise greater than it would otherwise be. When, for example, we hold a lighted match over a lamp, we are the more startled by the slight explosion because we have attentively awaited it; and there are many games for children in which the combined effect of expectation and surprise furnish an essential part of the pleasure, such as those where persons or objects are hidden. The excitement, too, which is caused by loud and sudden sounds is of the same character. M. Reischle, in his fine paper on child’s play, distinguishes a special group of expectation and surprise games, and points out that the little ones peek while their comrades are hiding, and yet are overjoyed to find them, and apparently surprised. In many throwing and catching games both elements are influential in heightening the stimulus, and special plays grow out of them, such as “Hide-and-Seek,” “Blind-Man’s Buff,” “Drop the Handkerchief,” as well as many games of chance. Indeed, in the last named the stimulus of surprise is often of special importance,[348] and one of the chief sources of pleasure is the tension of expectancy followed by the sudden decision on the fall of dice.