3. The mother-in-law may re-awaken in the son-in-law, in the manner we have already indicated, feelings which are incestuous in origin, being a displacement of those originally directed towards his own mother; the repression of these feelings of affection then giving place to their opposite--a feeling of repulsion or hostility--as a means of preventing the irruption into consciousness of the tabooed incestuous desires. As some indication of the reality of this factor, apart from the results of psycho-analysis, may be mentioned the fairly well recognised facts that it is possible for a man to be attracted to his future mother-in-law before he falls in love with his future wife, that he may hesitate as to whether he shall marry mother or daughter, or that he may fall back upon the mother should the daughter die or fail him in some other way. As further evidence too--on the negative side--we may refer to the extraordinarily numerous and widespread taboos and "avoidances" which affect the relations between son-in-law and mother-in-law among primitive peoples. 4. A corresponding displacement of incestuous desires, leading to a similar repression and reversal of emotion, may occur in the case of the mother-in-law herself, who, in virtue of this displacement, identifies her son-in-law with a son of her own (either real or imaginary); the one re-awakening in her incestuous tendencies originally aroused in connection with the other. Or again, the primary motive on the part of the mother-in-law may be unconscious sexual jealousy of her daughter, to whom she grudges the superior attractiveness of youth and the pleasures of dawning sexual life--a life which for the mother may be largely or entirely at an end. In this case she may unconsciously identify herself with her daughter, imagining, as it were, that it is she herself, and not her daughter, that is married to her son-in-law. In either case it is often the less tender and more sadistic elements of the mother-in-law's love which are directed to the son-in-law, since these are more easily reconciled with the maintenance of the requisite degree of repression than would be the case with the more gentle and affectionate components. [Sidenote: Step-child and Step-parent]