We have seen that the hate attitude is sometimes and to some extent brought about indirectly as a consequence of jealousy aroused in connection with the love attitude (jealousy being caused by interference with the successful function of the love impulses), sometimes more directly by a more general hostility between parent and child. In so far as the first case is concerned, the hate attitude is obviously dependent upon the existence of sexual rivalry between the child and one of the parents. Granted the existence of the love impulse of the child towards the parent of the opposite sex, the conditions of this rivalry are to be found whenever the two parents live together--in fact wherever there is marriage, and more especially wherever there is monogamy. Now marriage of some sort would seem to exist in practically every human community--both primitive and cultured--that has as yet been subjected to any degree of careful study or investigation; in fact there is every reason to regard it as an institution fundamentally characteristic of the human race and of immemorial antiquity. It is therefore not surprising that we find evidence of sexual jealousy between parents and children in many early myths and customs and in the legends and beliefs of many peoples, both cultivated and uncivilised. There is good ground for supposing that parent hatred based on jealousy has been called into existence in innumerable successive generations and has thus had ample opportunity to impress itself on the forms, traditions and institutions of human society. [Sidenote: and especially of monogamy] [Sidenote: Parent-child jealousy perhaps less pronounced in the Totemic Age]