Using field-based observations and standardized measures of the home environment and child development, the authors followed 59 rural Jamaican women and their offspring from birth to age 5. The findings suggest that conjugal multiplicity, a female reproductive pattern characterized by multiple unions, maternal unmarried status, and absent father, does not necessarily result in poorer developmental outcomes for preschool-aged children. Rather, it is a strategic adaptation to the conditions of poverty that may, in fact, provide developmental advantages for poor children in rural Jamaica. Households in which there are six or more maternal siblings, however, appear to compromise child development regardless of multiple unions, conjugal status, or father's presence.