Anthony Giddens, Social Theory and Modern Sociology (Cambridge: Polity Press, 1987), p. 357. Recent research on this topic is summarized and assessed in Gordon Wenham, Genesis 16–50, Word Biblical Commentary 2 (Dallas: Word Books, 1994), pp. xx–xxviii; the best recent study is P. Kyle McCarter, “The Patriarchal Age,” in Hershel Shanks, ed., Ancient Israel (Washington, DC: Biblical Archaeology Society, 1988). See also my brief treatment of these issues in “Genesis, Book of,” Anchor Bible Dictionary, vol. 2, pp. 937–938.