Research News

Subtle Discrimination Harms, Too

Effects of perceived discrimination stronger for black participants


IPR researchers find that adolescence might be a critical period when it comes to shaping black adult stress biology.

The deaths of Michael Brown, Tamir Rice, Eric Garner, and others continue to frame the national conversation about race relations. Yet “A lot of the conversations around Ferguson, etc., have been about the impacts of these really overt forms of discrimination that are, in some cases, deadly,” said IPR psychobiologist Emma Adam. “But there are more subtle ways in which discrimination is hurting and harming African Americans.”

In a recent IPR working paper, Adam, IPR social psychologist Jennifer Richeson, several IPR graduate research assistants, and their colleagues consider whether experiences of perceived racial and ethnic discrimination (PRD) during adolescence and young adulthood affect how bodies react to stress later in life. 

Emma Adam

The researchers surveyed 120 black and white adults from the Maryland Adolescent Development in Context Study (MADICS)—a longitudinal study that followed nearly 1,500 students in the state for 20 years, starting in seventh grade. Throughout the course of the MADICS survey, participants were asked about their personal experiences with PRD. Adam, Richeson, and their colleagues then collected saliva samples three times daily for a week from 120 of the MADICS participants as adults. The researchers used the samples to assess participants’ diurnal cortisol profiles—a biomarker of stress. Normal cortisol levels start off high upon waking, increase in the half hour after waking, and decline over the rest of the day—with the lowest point around midnight.  Under stress, cortisol levels tend to be lower on waking and slightly higher in the evening, resulting in a flatter diurnal cortisol profile, and in some cases, lower average cortisol across the day.

Jennifer Richeson

Preliminary results suggest that while PRD appears to result in flatter diurnal cortisol profiles for both blacks and whites, effects on overall cortisol levels were stronger for black participants. Increased exposure to PRD among black participants predicted lower waking cortisol and lower total cortisol throughout the day when compared with their white counterparts—an indicator of chronic stress called hypocortisolism.  Hypocortisolism has been linked to fatigue and chronic pain, as well as overactive immune and inflammatory systems. 

Furthermore, the researchers find that adolescence might be a particularly critical period when it comes to shaping black adult stress biology. While more recent experiences of racial and ethnic discrimination during adulthood were associated with acute increases in cortisol, earlier histories of PRD during teen years were associated with considerably lower, flatter cortisol profiles.

The stark difference between the results of white and black participants surprised the researchers. “We expected to see the flatter, diurnal rhythms for both blacks and whites, but we didn’t expect to see how much lower the overall curves were for blacks exposed to high PRD in adolescence,” Adam said.

As the researchers point out, exposure to discrimination is more common among racial and ethnic minorities in the United States—meaning they might experience PRD more frequently and with a greater impact than their majority counterparts.

“One conclusion people could draw is that we need to help African Americans or other individuals exposed to discrimination to cope better with stress,” Adam said. “But I don’t think that’s a fair policy conclusion from this. The fair policy conclusion is that we really need to be addressing, in a very broad societal way, race relations in the United States and improving them.” 

Emma Adam is professor of human development and social policy and an IPR fellow. Jennifer Richeson is MacArthur Foundation Chair and professor of psychology and African American studies and an IPR fellow. For more information, read the IPR working paper, “Developmental Histories of Perceived Racial/Ethnic Discrimination and Diurnal Cortisol Profiles in Adulthood: A 20-Year Prospective Study” (WP-14-18).

For more race and ethnicity research, read:

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Racial Disparities in America, Pt. I Better Measure for Racial Disparities in Causes of Death To Reduce Mass Incarceration, Recognize Humanity