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}