There’s no question that “a dozen pairs of arms” can make lighter work of family life. Society should applaud those who step up to try to rescue adults and children left adrift in a nation where, despite promising trends, many children still grow up outside an intact two-parent family.

But Americans should not presume that society can successfully replace families headed by married parents with models oriented more around kith and kin. Caution is especially warranted as extended families and communities struggle to foster upward mobility or to raise the next generation successfully in circumstances where the family once anchored by marriage has broken down in their midst.

It turns out that the relationship between nuclear families and larger communities is more symbiotic than substitutionary; more interdependent than interchangeable. Whatever the merits of extended or other nonnuclear forms of family life, research has yet to show that they are entirely equipped to shoulder the unique role of a child’s two parents.