Matthew effects for whom?

Which children are most at risk of experiencing a Matthew effect in reading? We investigated this question using population-based methodology. First, we identified children entering kindergarten on socio-demographic factors (i.e., gender, race/ethnicity, and socioeconomic status) known to index the relative risks and resources available to them as beginning readers. Second, we fitted growth curve models to the kindergarten-third-grade reading scores of these children as they participated in the Early Childhood Longitudinal Study-Kindergarten Class (ECLS-K) study. Third, we compared the relative reading achievement (as measured in standard deviation units from the sample's overall mean across the study's time points) of the children who were most and least at risk for reading disabilities. We found that the population subgroups most at risk for reading disabilities fell further behind typical readers over time. By contrast, those least at risk for reading disabilities did not move further ahead. Based on these findings, we conclude that a one-sided Matthew effect exists and that, moreover, it is likely to be experienced by children who are at greatest risk for reading disabilities.