Organic chemistry can be an insurmountable “gateway” course for otherwise-qualified students in pre-health pathways. Recent data indicate that organic chemistry increases drop-out risk for females and underrepresented minority students (URMs), raising the provocative possibility that sleep disparities are an underrecognized contributor to achievement gaps in gateway STEM courses.
In Study 1, 481 students enrolled in organic chemistry courses completed sleep questionnaires at the beginning, midpoint, and end of the semester. In Study 2, non-chemistry majors were randomly assigned to normal sleep (8 hours) or sleep restriction (5.5 hours) before taking an organic chemistry virtual lecture and test. In Study 3, 35 students wore actigraphy for five nights and could earn extra credit on a mid-semester test by averaging ≥8 hours of sleep; actigraphy sleep durations were compared to 40 active-control students who only received sleep education.
In Study 1 (classroom), URM and female students earned lower organic chemistry grades than comparison students, p<.001. Baseline weekday sleep duration predicted test grades across the semester, and students who improved their weekday sleep subsequently improved their organic chemistry grades. In Study 2 (laboratory), mild sleep loss impaired meta-cognitive judgments of organic chemistry learning, a potential causal mechanism for reduced persistence in chemistry courses. In Study 3 (classroom), when better sleep behaviors were incentivized by extra credit, students slept an hour longer/night than control groups (7.8 vs 6.8 hours, p<.001). These benefits persisted 1 month later into finals week when sleep behaviors were not externally incentivized (7.3 vs 6.3 hours, p=.001). Improving sleep improved performance on difficult short answer questions after correcting for pre-final grades (Madjusted=78% vs 72%, p=.04).
Sleep disparities contribute to achievement gaps in gateway STEM courses, but incentives can reverse poor sleep habits. University administrators should develop and implement behavioral change programs to reduce sleep disparities.