From all of these lines of argument, without going over the evidence in greater detail, it seems reasonable to conclude with Westermarck "that the hypothesis of a primitive state of promiscuity has no foundation in fact and is essentially unscientific." The facts put forth in support of the theory do not justify the conclusion, Westermarck says, that promiscuity has ever been a general practice among a single people and much less that it was the primitive state. Promiscuity is found, however, more or less in the form of sexual irregularities or immorality among all peoples; more often, however, among the civilized than among the uncivilized, but among no people has it ever existed unqualified by more enduring forms of sex relation. Moreover, because promiscuity breaks up the social bonds, throws the burden of the care of children wholly upon the mother, and lessens the birth rate, we are justified in concluding that promiscuity is essentially an antisocial practice. This agrees with the facts generally shown by criminology and sociology, that the elements practicing promiscuity to any great extent in modern societies are those most closely related with the degenerate and criminal elements. Those elements, in other words, in modern society that practice promiscuity are on the road to extinction, and if a people generally were to practice it there is no reason to believe that such a people would meet with any different fate. _The Earliest Form of the Family Life in the Human Species_, therefore, is probably that of the simple pairing monogamous family found among many of the higher animals, especially the anthropoid apes, and also found among the lower peoples. This primitive monogamy, however, as we have already seen, was not accompanied by the social, legal, and religious elements that the historic monogamic family has largely rested upon. On the contrary, this primitive monogamy rested solely upon an instinctive basis, and, as we have seen, unless children were born it was apt to be relatively unstable. Permanency in family relations among primitive peoples depended largely upon the birth of children. Thus we find confirmed our conclusion drawn some time ago that family life rests primarily upon the parental instinct. That it still so rests is shown by the fact, as we shall see later, that divorce is many times more common among couples that have no children than among those that have children.