Individual differences in academic trajectories from elementary to late middle school: Influences of gender, ethnicity, and income

Longitudinal academic data for a cohort of elementary to middle school students from a small diverse (50% Caucasian, 44% African American, 5% other ethnicity) Southeastern public school were analyzed with hierarchical modeling (HM). The influences of and interactions among gender, ethnicity, and income on academic growth were examined. The hypotheses tested included: (1) achievement gaps exist at 3rd grade, (2) gaps grow from 3rd to 8th grades, and (3) gender differences are more apparent in analyses of the tail distributions than in averages of the overall distribution. Performance data were scale scores for language arts, math, and science domains, from a widely-used standardized test. Ethnicity and income were strongly correlated (r(630)= 0.79, p<.01). Performance gaps by ethnicity were found at 3rd grade in language arts (beta 02 = -20.61, p<.05) and science (beta02 = -17.58, p<.05), and differences in linear and quadratic growth by ethnicity and income opened a performance gap in math by 8 th grade (beta22=-2.42, p < .05 beta 32=0.19, p < .05), with African American students averaging lower than Caucasians. Influences of ethnicity and income were large and stable in the tails, with low income and African American children over-represented in the bottom tail and nearly absent from the top tail over time. A significant interaction between gender and ethnicity showed African American boys scoring significantly lower in science than their peers at 3rd grade (beta04=-20.90, p<.05). The HM results predicted a significant acceleration in science growth by boys relative to girls after 6th grade (beta21=-2.89, p<.05 beta 31=0.25, p<.05). Analyses of the tail distributions make clear that average differences obscure important information: sex differences differed by academic domain, by tier of performance, and changed with time. These complex results preclude simple generalizations of "male advantage" or "female advantage" by academic domain.