Dr. Jordan Leitner of the University of California at Berkeley and three colleagues have published a study of the relationship between White racial attitudes and the health outcomes of Black Americans. Here are some things we already know:

• African-Americans have a higher death rate from cardiovascular diseases (e.g., heart attacks, strokes) than White Americans. (Other diseases as well, of course.)
• The perception by Blacks (and others) that they are being discriminated against (e.g., being followed by store employees, being pulled over by the police for a minor offense) is associated with physiological stress responses known to cause circulatory problems, and with increased mortality. However, since these studies measure perceived rather than actual discrimination, a skeptic could argue that Blacks only imagined that Whites were biased against them.
• African-Americans have higher death rates in locations where national surveys show that anti-Black attitudes are greater. But since these surveys include both Black and White respondents, it could be argued that the results were influenced by the attitudes of Black people who hate themselves.

Social psychologists distinguish between two types of prejudice. Implicit bias refers to automatic responses that are unintentional, and of which people may not be aware. Implicit bias was not related to any of the outcomed measured in this study. Explicit bias refers to responses that are deliberate and intentional. In this study, explicit bias was defined as the difference between how warmly (on a 10-point scale) participants said they felt toward White and Black Americans.

Leitner and his colleagues used a data base from Project Implicit consisting of the scores of about 1.4 million White Americans on the Implicit Association Test (IAT), a measure of implicit bias, collected between 2003 and 2013. When filling out the IAT, the participants indicated their race, age and gender, and completed the measure of explicit bias. The county in which their computer was located was determined from their Internet protocol address. Although it is large, this is not a representative sample of Americans, since the participants were younger than the average resident of their county. To correct this bias, the researchers weighted the responses of older participants more heavily. The results were the same with or without this correction.

In Study 1, racial bias was correlated with data from a 2012 telephone survey by the Centers for Disease Control (CDC), in which both race and county of residence were identified. Two questions were of interest. Access to affordable health care was measured by asking respondents whether they had ever, in the past year, needed to see a doctor but did not because of the cost. Coronary disease diagnosis was indicated by whether they reported being told by a health professional that they had a heart attack or heart disease.

In Study 2, racial bias was related to county-level statistics, also from the CDC, indicating the age-adjusted death rates from circulatory diseases of Blacks and Whites from 2003 through 2013. To control for alternative explanations, the data analyses of both studies statistically eliminated the effects of the following county-level characteristics: population, education, income, residential segregation, housing density and geographical mobility.

Below are scatterplots showing the outcomes of the two studies. Each dot represents a county and the lines indicate the statistical averages.

1. Blacks overall reported less access to affordable medical care. More importantly, as explicit racial bias among the county’s Whites increased, Blacks had less access to affordable medical care. Explicit bias did not affect Whites’ access to medical care.
2. However, explicit bias had no significant effect on coronary disease diagnosis among either Blacks or Whites.
3. In the second study, they found that the higher the explicit racial bias among Whites, the more likely both Blacks and Whites were to die of circulatory diseases. However, this relationship was stronger for Blacks than it was for Whites. For example, among counties in which Whites were high in explicit racial bias, the difference between Blacks’ and Whites’ death rates from circulatory diseases was 62 per 100,000. Among counties low in explicit bias, the difference was 35 deaths per 100,000.

According to the authors, this is the first large-scale study to demonstrate that White prejudice increases the death rate due to coronary disease of African-Americans living in the same counties. However, racial bias did not affect Black death rates due to cancer. Thus, physiological stress due to discrimination and its effects on the cardiovascular system appears to be critical in producing this effect.

The results of Study 1 imply that these increased deaths were also due in part to Blacks’ reduced access to affordable medical care. The failure of prejudice to affect coronary disease diagnosis among Blacks could be related to their difficulties in obtaining health care. Diagnosis and treatment require doctor visits, but death does not.

The fact that explicit racial bias predicted Black outcomes but implicit bias did not suggests that these health outcomes were an result of conscious bias on the part of the White majorities in these counties. Failure to provide adequate health care for poor people and minorities is an outcome of social policy decisions made by politicians and by corporate executives such as the managements of hospitals and clinics. Although the present data were collected prior to the Affordable Care Act, it would not be surprising if many of these same counties were located in states that failed to take advantage of the federal government’s offer to expand Medicaid in 2014.

I suspect that White prejudice at the community level has many other effects on the lives of African-Americans in addition to limiting access to health care. Black-White wage inequality and criminal justice policies affecting Blacks would seem to be obvious topics for future research.

You may also be interested in reading:

Outrage

The Implicit Association Test: Racial Bias on Cruise Control

Old-Fashioned Racism