The difficulties are, however, not really so formidable as they might at first seem to be. If a child is, on the one hand, highly susceptible to the contagion of laughter, there is, on the other, no expression of his feeling in which he is more spontaneous. The swift directness of the “natural” or spontaneous laugh may be readily discriminated by a fine observer. Not only so, but a difference may be detected in the tone of the laughter when it is perfectly natural and real, and when it is merely imitative and artificial. The note of affected laughter is well known to careful observers of children. It is particularly plain where a child is not merely reproducing the laughter of others at the moment, but has it suggested to him by others that a thing is laughable. Miss Shinn’s niece developed at the end of the second year a forced laugh on hearing the word “funny” employed by others. The best safeguard against this error is to choose an only child who is well isolated from mirthful surroundings. This need not be so cruel an experiment as it looks. In the social world of the merry little Ruth, nobody, we are told, was a “laughing person”. This circumstance gives great value to the observations made on this child. Her laughter was probably as purely self-initiated as anything in child-life can be. It may be added that, even if we could not eliminate the imitative and the artificial element, there would still be a pretty wide field for careful observation in the child’s own freer type of mirth. For, as all his friends know, his hearty laughter is frequently a response to things which leave us dull “grown-ups” wholly unaffected, or affected in quite another way. {188} With regard to the development of the expressive movements themselves I can find but few data at hand. These are enough, however, to show that the process of differentiation commences during the first year. Mrs. Moore tells us that her boy in the thirty-third week acquired a new form of smile “which gradually but not entirely supplanted the (earlier) broad open-mouthed smile. . . . The nose was wrinkled up, the eyes nearly closed. . . . This smile seemed to express an extreme and more conscious enjoyment.”[120] Preyer remarks that his boy developed in the last three months of the first year “a more conscious movement of laughter,” which, presumably, had a different character as an expressive movement. In the case of the boy C., of whom I have written elsewhere, a new and clearly differenced note was detected in the laugh of defiance (to be referred to later) which appeared early in the second year. Mrs. Hogan says she noticed a “mischievous laugh” at the age of fifty-five weeks, whereas Preyer remarks that the first “roguish laugh” occurred in his boy’s case at the end of the second year. A more precise record of the phonetic changes in laughter during the first two or three years is greatly to be desired.