This article provides a brief history of interpretations of Head Start's objectives over the last 4 decades. We begin with the founding goal of helping children prepare for school and the later misguided adaptation of increases in IQ scores as an indicator of children's readiness. We then discuss Head Start's more contemporary objectives, social competence and school readiness, and discuss the relation between these two constructs. Only by defining at the outset what Head Start is striving for will we be able to judge objectively if the program has succeeded and create social policies that facilitate its effectiveness.