2. With this first start in the sense of personality we find also the beginning of the recognition of different personalities. It is evident that the sense of another's presence thus felt in the infant's consciousness rests, as all associations rest, upon regularity or repetition; his sense of expectancy is aroused whenever the chain of events is started. This is soon embodied largely in two indications: the face and the voice. But it is easy to see that this is a very meagre sense of personality; a moving machine which brought pain and alleviated suffering might serve as well. So the child begins to learn, in addition, the fact that persons are in a measure individual in their treatment of him; that their individuality has elements of uncertainty or _irregularity_ about it. This growing sense is very clear to one who watches an infant in its second half year. Sometimes its mother gives it a biscuit, but sometimes she does not. Sometimes the father smiles and tosses the child; sometimes he does not. Even the indulgence of the grandmother has its times and seasons. The child looks for signs of these varying moods and methods of treatment; for his pains of disappointment arise directly on the basis of that former sense of regular personal presence upon which his expectancy goes forth. This new element of the child's sense of persons becomes, at one period of its development, quite the controlling element. His action in the presence of the persons of the household becomes hesitating and watchful. Especially does he watch the face, for any expressive indications of what treatment is to be expected; for facial expression is now the most regular as well as the most delicate indication. Special observations on H.'s responses to changes in facial expression up to the age of twenty months showed most subtle sensibility to these differences; and normal children all do. Animals are also very expert at this. All through the child's second year, and longer, his sense of the persons around him is in this stage. The incessant "why?" with which he greets any action affecting him, or any information given him, is witness to the simple puzzle of the apparent capriciousness of persons. Of course he can not understand "why"; so the simple fact to him is that mamma will or won't, he knows not beforehand which. He is unable to anticipate the treatment in detail, and he has not of course learned any principles of interpretation of the conduct of father or mother lying back of the details.