A new EPI study of the academic preparation of kindergartners by social class and race ended up being less about absolute preparation of children at the beginning of school and more about how prepared they are relative to one another. In short, children do not start school as equals. According to Inequalities at the Starting Gate: Cognitive and Noncognitive Skills Gaps between 2010–2011 Kindergarten Classmates, children’s school preparation is highly unequal, and what determines being better or worse off is a student’s social class.

While inequalities in the cognitive abilities of our young people have been documented by previous research (see EPI’s Inequality at the Starting Gate study from 2002 and Robert Putnam’s new book, Our Kids: The American Dream in Crisis), our study uses a dataset that allowed for examining how prepared children are in both cognitive (reading and math) and noncognitive domains (social skills, persistence, and creativity, among others). The data set (the National Center for Education’s Early Childhood Longitudinal Study of the Kindergarten Class of 2010-2011) also offers information on individual and family demographic characteristics and various enrichment activities that parents undertake with their children, enabling assessment of the importance of these variables for children’s preparation. All in all, the data allowed us to understand the broad school readiness of a recent generation of students. These students were born after—and thus presumably benefited from—the spread of prekindergarten education and other advances in school preparedness research and policymaking. But these children were also raised in a context of economic stagnation.

Consistently, results showed that having less money puts children at a relative disadvantage, in terms of the cognitive and noncognitive skills developed by the age of 5, while having more money benefits them, as skill levels increase along with social class. Most gaps are striking in size and appear for all the examined cognitive, noncognitive, and executive function skills. For example, children in the highest socioeconomic group have reading and math scores that are a full standard deviation larger than the scores of their peers in the lowest socioeconomic group. To give a sense of how large this gap is, it would take up to four independent, “substantively important,” education interventions to close the gap, according to a “classification of effects” from the U.S. Department of Education’s What Works Clearinghouse. The social-class-based gaps in other skills such as working memory, persistence in completing tasks, and self-control are 0.7, 0.4, and 0.5 standard deviations, respectively.

Whether current performance gaps in cognitive and noncognitive skills between children of different economic classes at the beginning of school will affect children’s future social class remains to be determined. However, the counter relationship—that the significant effect of current social class on current performance—is apparent.

While forthcoming blogs will focus on gaps by race and on other findings of the study, this headline finding about the link between school readiness and social class really deserves thorough consideration here. That early education inequalities are a reflection of economic inequalities raises serious concerns about the presumed relationship between education and social mobility. It also calls into question the claim that we can reduce income inequality if we just focus more on education. More broadly, the finding that economic inequalities produce skills inequalities before children even begin school means that we, as a society, are not providing the proclaimed equality of opportunities to children.

The consequences of these stark income-based inequalities are potentially dire. Research has shown that, on average, social-class based education inequalities persist throughout the student school career. For example, academic performance of students who are eligible for free or reduced-price lunch is about a full standard deviation below non-eligible students (according to the National Center for Education Statistics’ National Assessment of Educational Progress (NAEP) in 2013). And the odds that even high-performing low-income students graduate   from college are equal to the odds that the lowest-performing students in the highest income brackets graduate, notes Robert Putnam in his new book, Our Kids: The American Dream in Crisis. NAEP data, Putnam’s study, and other studies suggest that social class drives education performance at any age, and that it can undermine the real educational opportunities afforded to our low-income youth.

Unfortunately, early inequalities persist due to insufficient political action and possibly a lack of awareness of the size of the problem and/or ultimate consequences of these inequalities for both individuals and the country itself. Not only are schools given children in very unequal circumstances, but also the school system treats children very unequally. And these funding inequities and segregation of students by race and/or economic status compound children’s individual challenges and constrict their progress. Research-based knowledge of practices that work is not being translated into sufficient practical support of disadvantaged students before and after they start school. Programs aren’t inclusive and comprehensive enough to reach all of those children that need to be reached. Policies borne of rethinking the solution to inequalities at the beginning of kindergarten should aim to provide real opportunities to all children. In addition to the current push for early education policies, the findings of the study also call for embracing a wider economic and political solution that tackles the intimate link between inequality and education. More comprehensive policies are needed to alter the vicious cycle of inequality begetting unequal education begetting more inequality.