School do not create achievement gaps. By the time children enter kindergarten, dramatic socio-economic and racial school-readiness gaps are deeply entrenched. Data from the Early Childhood Longitudinal Study (ECLS-K), a large, nationally representative survey, show that at kindergarten entry, the average cognitive scores of children from high socioeconomic backgrounds are approximately three-fifths of a standard deviation higher than those of children from lower socioeconomic backgrounds (Reardon, 2003;lee & Burkham, 2002; Coley, 2002). Significant differences in cognitive assessment scores are also evident between racial groups, with white students scoring two-thirds of a standard deviation higher on a test of reading. The Hispanic-white gap is even more pronounced (Fryer & Levitt, 2004; Rumberger & Anguiano, 2004). Study after study confirms this early childhood gap, which seems to surface as early as 18 months and widen throughout early childhood (Shonkoff & Phillips, 2000).