“…Yet in moving beyond nuclear, middle-class family households, researchers serious about studying cocaregiving and family group dynamics can find themselves challenged to accurately define the core coparental unit for study. For example, within the sizeable underclass in the United States today, both blood and fictive kin frequently organize flexibly to provide a broad family base for young children (CrosbieBurnett & Lewis, 1999), promoting continuous responsibility for dependent children even across changes in relationships among adults. In such families, the relevant coparenting "unit" may involve many or even all of those adults involved in the nurturance and support of an identified child regardless of household membership, demanding that researchers be especially attentive in defining the functional family group (Brooks-Gunn &Furstenberg, 1986;Crosbie-Burnett&Lewis, 1999;Roschelle, 1997;Stack, 1974).…”