The baby's increased interest in seeing centered especially on the faces about her, at which she gazed with rapt interest. Even during the period of mere staring, faces had oftenest held her eyes, probably because they were oftener brought within the range of her clearest seeing than other light surfaces. The large, light, moving patch of the human face (as Preyer has pointed out) coming and going in the field of vision, and oftener chancing to hover at the point of clearest seeing than any other object, embellished with a play of high lights on cheeks, teeth, and eyes, is calculated to excite the highest degree of attention a baby is capable of at a month old. So from the very first--before the baby has yet really seen his mother--her face and that of his other nearest friends become the most active agents in his development and the most interesting things in his experience. Our baby was at this time in a way aware of the difference between companionship and solitude. In the latter days of the first month she would lie contentedly in the room with people near by, but would fret if left alone. But by the end of the month she was apt to fret when she was laid down on a chair or lounge, and to become content only when taken into the lap. This was not yet distinct memory and desire, but it showed that associations of pleasure had been formed with the lap, and that she felt a vague discomfort in the absence of these. Nature has provided an educational appliance almost ideally adapted to the child's sense condition, in the mother's face, hovering close above him, smiling, laughing, nodding, with all manner of delightful changes in the high lights; in the thousand little meaningless caressing sounds, the singing, talking, calling, that proceed from it; the patting, cuddling, lifting, and all the ministrations that the baby feels while gazing at it, and associates with it, till finally they group together and round out into the idea of his mother as a whole. Our baby's mother rather resented the idea of being to her baby only a collection of detached phenomena, instead of a mamma; but the more you think of it, the more flattering it is to be thus, as it were, dissolved into your elements and incorporated item by item into the very foundations of your baby's mental life. Herein is hinted much of the philosophy of personality; and Professor Baldwin has written a solid book, mainly to show from the development of babies and little children that all other people are part of each of us, and each of us is part of all other people, and so there is really no separate personality, but we are all one spirit, if we did but know it. 5. Sex Differences[62]