Despite known risk factors associated with families headed by single mothers such as delinquency, substance abuse, and early unprotected sex, researchers have rarely focused on how family relations positively shape the developmental trajectories of youth living in nontraditional families. The purpose of this correlational study was to examine the relationship between the independent variables of ethnicity, parent-child relationship, and family interaction (including the relationship with important non-parental adults) and the dependent variables of developmental outcomes (social and emotional competence) for youth living in families headed by single mothers. The associations were investigated using data collected from the Project on Human Development in Chicago Neighborhoods, a longitudinal cohort study. The relationships between variables were analyzed using a descriptive statistics method. The results of the study indicated no race-related differences in a child's closeness to mother in single-mother families. A significant positive correlation showed a difference in closeness to family members across ethnic groups, by age. Multiple regression analysis was employed to determine if there were statistically significant differences between closeness to the mother or family members, and the outcomes. The findings indicated that closeness to family was positively correlated to emotional outcomes for youth, and a significant positive correlation was found between family interaction and social outcomes. These results may have implications for positive social change by providing public health practitioners with strategies to support positive youth development, altering the future of youth, families, and society which will ultimately benefit from a stronger population of emotionally and socially competent young adults.