Little is known about the relationship between family income and children's non-cognitive (or socio-emotional) skill formation. This is an important gap, as these skills have been hypothesized to be a critical link between early outcomes and adult socioeconomic status. This paper presents new evidence of the importance of family income in the formation and evolution of children's non-cognitive skills using a recent US panel dataset that tracks children between grades K-5. Findings suggest an important divergence in non-cognitive skills based on family income that accumulates over time and does not seem to be explained by children's health status differences. (C) 2016 Elsevier Ltd. All rights reserved.