In the light of these researches and observations the normal course of development of the child's affections, so far as they concern us here[8], would seem to be somewhat as follows[9]: In the earliest period of its existence those tendencies which are afterwards to develop into love, affection and desire for persons or objects in the outer world are at first connected with sensations from various parts of the child's own body. This constitutes the auto-erotic stage in which the child is for the most part concerned with outer things as objects of desire merely in so far as they serve to bring about his own bodily comfort and satisfaction. To begin with there is indeed in all probability no clear distinction between the self and the environment or between the animate or inanimate objects of the environment. Corresponding to the gradual development of these distinctions there is found the beginning of what is called by Freud "object love", the experience of desire for, and affection towards, some object or person of the environment, the highest manifestation of which is found in the passionate and all absorbing loves of subsequent adolescent or adult life. This beginning of object love is a most important stage of development, since on its success depends not only the possibility of a normal growth of the sexual trends to full maturity, but also, to a great extent, the occasion and opportunity for the unfolding of many of the higher altruistic tendencies and motives. [Sidenote: Heterosexuality] It is natural that, in the gradual transition from auto-erotism to object love, the first object of the child's affection should be chosen from amongst those who administer to its bodily needs and comfort. Thus it is probable that in the conditions of normal family life, the mother or the nurse is, in nearly all cases, the first person selected. It would appear, however, that at a relatively very early age, the sex of the child begins to exert an influence on the choice of the loved object, so that (as we have already noted) we find after a time a predominant tendency for selection of the parent of the opposite sex as the object of affection. This perhaps takes place to some extent in virtue of an already ripening tendency to heterosexual selection in the child. But there can be little doubt that in many cases another factor is to some extent operative in bringing about this result, _i. e._ the tendency of the child to appreciate and to return the manifestations of affection that are shown towards it. Now the parents in virtue of their developed heterosexual inclinations tend very frequently to feel most attracted to those of their children who are of the opposite sex to their own and thus (consciously or unconsciously) to indulge in greater manifestations of affection towards such children; this unequal distribution of affection being in turn perceived and reciprocated by the children themselves.