Do race-based stressors contribute to the achievement gap?

Schools, teacher quality and family income all play a large role in student success, but these factors do not fully explain the academic differences seen in the U.S. between whites and disadvantaged racial/ethnic minorities, including blacks and Hispanics.

In a review published in the journal American Psychologist, the researchers argue that the psychological stress associated with perceptions of discrimination and stereotype threat -- and the body's physiologic response to that stress -- may help explain the achievement gap.

More research is needed because "looking at both psychological and biological responses to stress will lead to a more complete understanding of why we have the racial/ethnic achievement gap," said study lead author, Dorainne Levy, who began the research while at Northwestern and is now a post-doctoral scholar at Indiana University.

The research team reviewed previous studies suggesting that blacks and Hispanics experience increased stress simply by belonging to a racial/ethnic minority group.

Race-based stress can be caused by perceived discrimination, or feeling like you've been treated unfairly based on your race. Another factor is stereotype threat, or the stress of wanting to perform well to overcome someone's negative expectation of the group you identify with.

Research also indicates that racial/ethnic minorities, particularly blacks, have altered stress biology compared with whites, including differences in levels of the stress hormone cortisol and sleep duration and quality.

"Stress, including the stress of racial discrimination, affects cortisol levels and sleep, which are important for cognition and learning," said study senior author Emma Adam, a professor of human development and social policy at Northwestern's School of Education and Social Policy and faculty fellow at the Institute for Policy Research.

Last year, Adam's team found that in both blacks and whites, everyday feelings of discrimination, especially during adolescence, can throw off the body's cortisol levels.

In African-Americans, however, the negative effects of perceived discrimination on cortisol are stronger than in whites, according to the study, one of the first to look at the biological response to the cumulative impact of prejudicial treatment.

"Racial inequality in educational outcomes is one of the biggest problems facing America today," Adam said. "We have to understand the origins of these disparities to reduce them."