According to Watson, the phenomena seen in this tendency of emotions inhibited at one point to seek other outlets are too complex to be explained on the basis of conditioned reflex responses. All that we can say at present is that too great emotional pressure is drained off through whatever channel environmental and hereditary factors make possible.[8] This vicarious mode of expression may become habitual, however, and interfere with a return to natural activities in a manner analogous to that in which the development of the erotic fetish often prevents the normal reaction to the original stimulus. Because the conditioned emotional reactions and substitutions of vicarious motor outlets take place at neurological and physiological levels outside the realm of consciousness, they are called unconscious activities of the organism. There are many other unconscious factors which also modify the sex life of the human individual. The most fundamental of these are the impressions and associations of the infancy period, which may well be classed as conditioned reflex mechanisms, but are sufficiently important to receive separate consideration. It is generally conceded by students of child psychology that the social reactions of the child are conditioned by the home environment in which the earliest and most formative years of its life are passed. It is not surprising, therefore, that the ideal of the opposite sex which the boy or girl forms at this time should approximate the mother or father, since they are the persons best loved and most frequently seen. The ideals thus established in early childhood are very often the unconscious influences which determine the choice of a mate in adult life. Or the devotion to the parent may be so intense as to prevent the transference of the love-life to another person and thus entirely prohibit the entrance upon the marital relation. Elida Evans has given some very convincing cases in illustration of these points in her recent book, "The Problem of the Nervous Child."[2] On the other hand, in those unfortunate cases where the father or mother is the object of dislike, associations may be formed which will be so persistent as to prevent the normal emotional reaction to the opposite sex in later years. This, too, results in the avoidance of marriage and the establishment of vicarious outlets for the sexual emotions, or less often in homosexual attachments or perversions of the sex life. Conditioned emotional reactions such as these play a dominant role in the social problem of sex, as will become apparent in succeeding chapters.