Study Finds Sleep Duration Does Not Account for Racial Disparities in Grades and Attendance Among Georgia Ninth Graders

Led by Henok Mulatu Teferi from Emory University’s Rollins School of Public Health, alongside co-first author Gina Marie Mathew from Stony Brook University, the study analyzed data from 406 ninth graders across two racially and ethnically diverse high schools. Ninth grade is particularly critical in the U.S. education system as it marks the transition into courses contributing to graduation and often sets patterns for absenteeism.

Previous studies have identified racial and ethnic disparities in grade point averages and school attendance, with links drawn between sleep and academic performance. However, it remained uncertain whether sleep differences significantly influenced these disparities. Utilizing counterfactual-based mediation analysis, the researchers examined how race and ethnicity, categorized as Asian, Black, Hispanic, or White, might impact academic outcomes through sleep measures: average sleep duration and mid-sleep on free days (MSFsc), a proxy for chronotype.

The findings highlighted that compared to White students, Black students had lower GPAs, with a regression coefficient of -2.70, while Asian students outperformed their White peers with a coefficient of 5.46. Attendance rates also varied, with Asian students showing a relative risk of 0.51 for absences compared to White students, indicating they were about half as likely to miss school. Hispanic students showed a similar pattern with a relative risk of 0.59.

Despite these evident disparities, the researchers found that sleep duration and MSFsc did not mediate the differences in academic outcomes. This null mediation result is significant given the clear presence of disparities in the data, suggesting that factors beyond sleep likely contribute to academic inequities.

The study complicates the common perception that addressing sleep issues could resolve achievement gaps. Although the National Sleep Foundation recommends 8 to 10 hours of sleep for teenagers, and prior research links inadequate sleep to poorer school performance, this study indicates that interventions focusing solely on sleep may not suffice to close the GPA or attendance gaps.

Some limitations of the study include its cross-sectional design, capturing only a single snapshot without tracking long-term impacts, and the reliance on self-reported sleep measures rather than objective assessments. The study calls for longitudinal research utilizing objective sleep data.

Furthermore, the results suggest that researchers should explore additional factors influencing chronic absenteeism, such as school climate, disciplinary practices, and social determinants. The findings underscore that while sleep is an important aspect of adolescent health, it cannot fully account for the complexities of educational inequity.

For educators and policymakers, the findings emphasize that while improving sleep health is beneficial, closing racial and ethnic gaps in academic performance requires addressing broader social and structural factors. The study serves as a reminder that disparities in academic success among Georgia ninth graders cannot be explained by sleep alone, redirecting focus toward a comprehensive understanding of the factors at play in American high schools.