03/27/2013 12:01 pm ET Updated May 27, 2013

Racism Passes Health Risk Down Generations

Recently, I wrote a piece for The Atlantic on how racism is bad for the body. For the bulk of the essay, I discuss how racism harms a single person's health directly -- and I link public health research with the NYPD's stop and frisk policy. But at the end of the piece, I write:

... no person discriminated against is an island. When conditions of social injustice affect this many people, and prompt poor health outcomes, risk passes down generations. And this damage isn't going away any time soon. Even in the absence of discrimination, Nancy Krieger argues that populations "would continue to exhibit persistent disparities reflecting prior inequities."

How does this work, exactly? We're probably aware of genetic traits and social habits -- desirable and undesirable -- that we've inherited from our parents. And we probably agree that racism is often taught by parents and learned by children. But how does health risk from racism pass down generations?

In 2009, Howard University College of Medicine researchers proposed a conceptual model of how discrimination harms a child's health. First, they divided the types of racial discrimination into microsystem (individual) and macrosystem (structural) exposures. Second, they argued that both types click on psychological and biological responses. These responses cause mental distress and changes in allostatic load (which means, for example, a person's immune response decreases and blood pressure increases). Ultimately, these changes result in poor health and create health disparities.

But what's especially striking is how the impact of discrimination flows from the parent to the child. In the Howard model, with the exception of racist bullying, both the microsystem and macrosystem exposures focus on parental experience. On the micro level, parents may suffer from harassment. On the macro level, they may also suffer from discrimination in housing, employment, and health care. These sources are not always neatly split. Personal and institutional discrimination can be two dimensions of the same event -- consider a leasing agent who discriminates against an apartment applicant. No matter the source, the health outcome may be the same.

To see the effects of discrimination, sometimes we need to follow its path downstream. We can imagine many scenarios. For example, we know minorities are disproportionately stopped, searched, and arrested for non-violent drug offenses. This can eliminate their ability to gain student loans and access to education, which can limit their employment opportunities. When this person becomes a parent, this can frustrate their ability to provide quality education, housing, and health care. As they attempt to provide in a system that delivers anything but opportunity, discrimination may also drain their emotional resources for parenting and shape their involvement with social systems that hurt them before.

This tells us that the effects of racism are often not instant. Racism is not an on/off switch for health. Perhaps what we need is a model that accounts for how events unfold over time and link lives together.

In a 2012 paper in the American Journal of Public Health, Gilbert Gee and colleagues proposed a life course perspective to think about racism and health inequities. How racism impacts health depends on a person's age. Among other things, a life course model accounts for sensitive periods, when social stressors exert the most impact on a person's future. One of the most sensitive periods, as one might expect, is early childhood.

But the reason may be less obvious. As we age, we enter (and exit) social systems. Gee and colleagues point out that these social systems -- for example, education, criminal justice, and labor -- drive health inequities. But the lives of parents and children are linked. So, when a parent is discriminated against in one social system, such as labor, it can affect a child during a critical development stage. In fact, research shows that early childhood poverty has long-term effects on that child's achievements, health, and income as an adult. The life course perspective shows how the effects of discrimination proliferate, are latent, and link lives together.

Discrimination creates fault lines across generations. Usually, when we think of inheritance, we think about genes, or social habits, or wealth. And these, no doubt, are important factors for health. But there's more. Discrimination works to constrain life chances. Sometimes the actual event occurs before the child is born. Even if we eliminate the micro and macro level sources of discrimination today, we are still behind -- and we've got a lot of catching up to do.

This blog originally appeared on March 19, 2013 at PLOS Blogs Public Health Perspectives.