Although primogeniture is commonly assumed to have prevailed throughout the world and firstborns are regarded as most likely to achieve success, many of the most prominent figures in biblical literature are younger offspring, including Isaac, Jacob, Joseph, Moses, Samuel, David, and Solomon. Central to the plot of most biblical stories, the sibling relationships depicted are rarely harmonious, and the surprising preference for younger siblings is an intriguing and unexplained pattern.

Using evidence from a wide range of disciplines. Frederick E. Greenspahn presents a seminal interpretation of this phenomenon. In this study, he demonstrates that ancient Israelite fathers were in fact free to choose their primary heirs. The Bible's propensity for younger offspring, Greenspahn shows, reflects neither a legally mandated norm nor a protest against the prevailing custom, but rather conforms to a widespread folk motif, evoking innocence, vulnerability, and destiny.

Within the biblical context, this theme heightens God's role in supporting ostensibly unlikely heroes. Drawing on the resources of law, anthropology, folklore, and linguistics, Greenspahn shows how, in portraying younger siblings triumphing over older ones, these tales serve as complex parables of God's relationship to his chosen people, and reflect Israel's own discomfort with the contradiction between its theology of election and the reality of political weakness.