ABSTRACT
One fundamental reason for the high breakup rate is that the nature of marriage has changed. The economic bond has become displaced by affluence, by female economic pursuit, and by state support; extended family pressures on marriages have all but vanished; and modern societies have become increasingly secular. Pair-bonds are considered to be an evolutionary development of enormous importance to the human species, a major reason for our extraordinary success in the world of nature. Human nature today still largely functions in these terms, but there is a joker in the deck. The evolved human pair-bond does not seem well matched with the marriage ideal of the modern nuclear family-voluntary, sexually-faithful, lifelong monogamy in which husband and wife share love and companionship. The modern nuclear family was a truly remarkable development in the history of human social organization, and probably the only example in history in which voluntary lifelong monogamy was widely practiced.
