We introduce the concept of stress disparities (systematic differences in perceived and biological stress across sub-groups of students) and hypothesize that stress disparities may help to account for disparities in academic outcomes. We propose to measure and test associations among race-based stress (RBSS, such as perceived racial discrimination), stress biology (cortisol daily rhythms and sleep hours and quality) and academic outcomes in 300 students followed for 4 years in a diverse high school. To provide experimental insights, we will implement an intervention designed to promote ethnic-racial identity (ERI) development, which we hypothesize will reduce the impacts of RBSS on stress biology and improve academic outcomes, particularly for minority youth. ... Read more about BIO Study: Race-based Biological Stress, Ethnic-Racial Identity, and Educational Outcomes: New Approaches to Studying Academic Achievement Gaps