This study examined the specific factors relative to healthy socialization and economic well-being that predicted toddler mental development in rural Paraguay. Thirty toddlers and their primary caregivers were assessed using the Bayley Scales of Infant Development-II (BSID-II), the Home Observation for Measurement of the Environment (HOME) to assess socialization, and a Family Resource Survey to assess economic well-being. As has been found in other studies, parent responsivity, parent support of child learning, and family economic well-being predicted BSID-II scores. Similar to results from other developing world samples, children's mental development scores decreased across the second year of life, a finding attributed to the parasitic load that many rural Paraguayan children carry, their family's lack of social capital, and inadequate parent-child socialization. The framework for the paper is centered on Amartya Sen's (1999) contention that family-, community-, and country-level well-being must be adequate to support healthy human development. (Contains 7 tables.)