The erotic impulse may have its responses conditioned in many other ways than the building up of erotic fetishes. Kempf has observed that the affective reactions of the individual are largely conditioned by the unconscious attitudes of parents, friends, enemies and teachers. For instance, one boy is conditioned to distrust his ability and another to have confidence in his powers by the attitude of the parents. Similarly, the daughter whose mother is abnormally prudish about sexual functions will surely be conditioned to react in the same manner towards her own sexual functions, unless conditioned to react differently by the influence of another person.[5] Through the everyday associations in the social milieu, therefore, the erotic impulse of an individual may become modified in almost any manner. Just as an emotional reaction may become conditioned to almost any other stimulus than the one which originally called it forth, so there is a tendency for any emotion to seek a vicarious outlet whenever its natural expression is inhibited. Were any member of the group to give free play to his affective life he would inevitably interfere seriously with the freedom of the other members. But the fear of arousing the disapproval of his fellows, which is rooted in man's gregarious nature, inhibits the tendency to self-indulgence. "A most important factor begins to exert pressure upon the infant at birth and continues throughout its life," says Kempf. "It is the incessant, continuous pressure of the herd ... to conventionalize its methods of acquiring the gratification of its needs."[5] The emotions thus denied a natural outlet seek other channels of activity which have received the sanction of social approval. It is obvious that the rigid social regulations concerning sexual activities must enforce repression of the erotic impulses more frequently than any others. The love which is thus denied its biological expression transmutes itself into many forms. It may reach out to envelop all humanity, and find a suitable activity in social service. It may be transformed into the love of God, and find an outlet in the religious life of the individual. Or it may be expressed only in language, in which case it may stop at the stage of erotic fantasy and day-dream, or may result in some really great piece of poetry or prose. This last outlet is so common that our language is full of symbolic words and phrases which have a hidden erotic meaning attached to them.