Researchers find biological evidence of the toll colorism takes on young adults

New research suggests that the bias against darker skin tones does more than affect social standing; it physically alters the body’s stress response mechanisms. A study published in Psychoneuroendocrinology links these specific experiences of discrimination to disruptions in cortisol levels and subsequent physical health declines in young adults. This research provides evidence that sociocultural stressors can bypass psychological defenses to impact biological function directly.

Health disparities between racial groups are well documented in the United States. However, broad racial categories often obscure the nuanced experiences of individuals within those groups. Antoinette M. Landor, an associate professor at the University of Missouri, sought to investigate these variations. Along with colleagues from several other institutions, Landor focused on the concept of colorism.

This term refers to bias that favors lighter skin over darker skin. It can come from outside one’s community or from within it. It acts as a layer of inequality separate from, though related to, racism. The researchers theorized that the stress arising from this specific type of bias creates a unique biological burden.

The team utilized an intersectional framework to guide their inquiry. This approach recognizes that systems of oppression do not operate in isolation. A person is not just influenced by their race or their gender separately. Instead, these identities overlap to create distinct experiences of privilege or marginalization.

Specifically, the study engaged with the “skin tone trauma model.” This theoretical model posits that skin tone is a primary marker for social stratification. It suggests that individuals with darker skin face more frequent and intense devaluation. The researchers aimed to see if this social trauma could be detected in the body’s hormonal rhythms.

They focused on the hypothalamic-pituitary-adrenal axis, often called the body’s central stress response system. When a person perceives a threat, this system activates a cascade of hormones. The end product of this cascade is cortisol. In a healthy individual, cortisol follows a specific daily pattern known as a diurnal rhythm.

Levels of this hormone typically spike roughly thirty minutes after a person wakes up. This surge helps mobilize energy to start the day. The levels then steadily drop as the day progresses. By bedtime, cortisol should reach its lowest point to facilitate sleep.

Chronic stress can disrupt this healthy curve. When the body stays in a state of high alert, the stress system may lose its sensitivity. The brain struggles to shut off the production of stress hormones. This results in a “flatter” diurnal slope.

A flatter slope means cortisol does not drop as much as it should during the day. This dysregulation is often associated with fatigue, depression, and cardiovascular issues. The researchers hypothesized that colorism acts as a chronic stressor that flattens this curve.

To test this, the team recruited 53 African American and Latino undergraduate students. These participants engaged in a rigorous data collection process over several weeks. At the start, the students rated their own skin tone using a visual scale. They also completed questionnaires detailing their recent experiences with ethnic-racial discrimination.

The most intensive part of the study involved collecting biological samples. Participants provided saliva samples three times a day for two consecutive days. They repeated this process every week for a month. This allowed the team to track cortisol fluctuations accurately over time.

Participants collected spit samples immediately upon waking, thirty minutes later, and right before bed. This provided the data points necessary to graph each individual’s cortisol slope. The researchers also asked participants to rate their general physical health at the beginning and end of the study.

The data revealed a clear pattern connecting appearance to social experience. Participants with darker skin tones reported more frequent instances of ethnic-racial discrimination. This finding aligns with sociological research suggesting that darker skin acts as a primary target for bias.

The study then connected these social experiences to biological markers. High levels of reported discrimination correlated with flatter diurnal cortisol slopes. The stress system appeared to lose its natural rhythm in those facing consistent prejudice. The body’s regulatory “brakes” seemed to function less effectively.

Finally, the analysis linked these hormonal patterns to general well-being. The flatter cortisol slopes were associated with poorer self-reported physical health six weeks later. This suggests a specific pathway for health deterioration. Darker skin leads to increased exposure to discrimination.

That discrimination acts as a persistent stressor that disrupts the endocrine system. Eventually, that physiological disruption manifests as a perceptible decline in physical health. The researchers controlled for initial health status to ensure they were capturing a change over time.

This biological “wear and tear” is consistent with a concept known as allostatic load. The body adapts to stress in the short term to survive. However, maintaining that state of adaptation requires energy and resources. Over time, this effort damages various bodily systems.

The findings support the idea that colorism contributes to this weathering process. It suggests that the health disadvantages faced by communities of color are not uniform. Those with darker skin may carry a heavier physiological load due to colorism.

The authors noted several limitations that provide context for these results. The sample size was relatively small, consisting of only 53 individuals. All participants were college students, who may have access to resources that buffer against stress. This specific demographic might not represent the general population of young adults.

Additionally, the study relied on participants to rate their own skin tone and physical health. Perceptions of skin tone can be subjective and influenced by social factors. Future investigations could benefit from objective measurements, such as using spectrophotometers to analyze skin color.

The researchers also suggest that future work should include more diverse age groups. Examining these dynamics in older adults could reveal how these effects accumulate over a lifetime. It would also be beneficial to look at participants from various socioeconomic backgrounds.

Despite these caveats, the study offers important insights for public health. It indicates that addressing health disparities requires looking beyond broad racial categories. Interventions may need to account for the specific stressors associated with skin tone.

Medical professionals and policymakers should be aware that colorism is a health risk factor. It is distinct from racism and requires targeted attention. The intersection of these biases creates a complex environment for young adults of color.

By identifying the biological footprints of this bias, the study validates the physical reality of social experiences. The phrase “getting under the skin” is often used metaphorically. This research suggests it is also a literal physiological process.

The study, “How colorism gets “under the skin”: The role of ethnic-racial discrimination and diurnal cortisol in the physical health of African American and Latino young adults,” was authored by Antoinette M. Landor, Katharine H. Zeiders, Alaysia M. Brown, Kayla M. Osman, Evelyn D. Sarsar, and Jasmine Godwin.