Paternity is certain; and, where descent is traced in the male line, "inheritance of power by sons becomes possible; and, where it arises, government is better maintained." The family cohesion is greater; and "this definite descent in the male line aids the development of ancestor-worship; and so serves in another way to consolidate society."[459] For these reasons chiefly he regards polygyny as a type of marriage higher than polyandry; though he remarks that, "were it not for the ideas of sacredness associated with that Hebrew history which in childhood familiarized us with examples of polygyny, we should probably feel as much surprise and repugnance on first reading about it as we do on first reading about polyandry."[460] But this is too favorable an estimate of the relative social value of polygyny. It is doubtful, to say the least, whether morally and physically it is more favorable to the offspring than polyandry; and it is almost certain that it is far worse in its effects upon the home and condition of women.[461] This fact alone, when considered in all its consequences, far outweighs the alleged relative structural advantages of polygyny, which besides have not been conclusively established. [455] Owing to the hard conditions of life, female beauty fades early among savage and barbarous peoples, sometimes even among those reckoned as civilized. A fresh wife is demanded when the first grows old. In some cases the husband is forbidden by custom to cohabit with his wife until the child is weaned, though suckling may continue two, three, or four years: WESTERMARCK, _op. cit._, 483-88; PLOSS, _Das Weib_, I, 58, 59 (fading beauty). [456] WAKE, _Marriage and Kinship_, 202 ff., thus summarizes the causes of polygyny: "_First_, the sterility of the first wife," as in the case of Rachel; "_secondly_, the length of time during which a woman suckles her child; _thirdly_, the sexual requirements of man while leading a hunting or pastoral mode of life; _fourthly_, the accidental scarcity of men; and, _fifthly_, the luxury or sensuality of man, or the desire for influence and power." [457] WESTERMARCK, _op. cit._, 489-91; _cf._ STARCKE, _op. cit._, 261. [458] WESTERMARCK, _op. cit._, 495,496; SPENCER, _op. cit._, I, 688. [459] SPENCER, _op. cit._, I, 688, 689, 690 ff., 697. _Cf._ on causes of polygyny, LUBBOCK, _Origin of Civilization_, 112. [460] SPENCER, _op. cit._, I, 682. _Cf._ the similar view of WAKE, _Marriage and Kinship_, 219.