摘要:Recent studies show that racism may influence health inequities. As individuals grow from infancy into old age, they encounter social institutions that may create new exposures to racial bias. Yet, few studies have considered this idea fully. We suggest a framework that shows how racism and health inequities may be viewed from a life course perspective. It applies the ideas of age-patterned exposures, sensitive periods, linked lives, latency period, stress proliferation, historic period, and cohorts. It suggests an overarching idea that racism can structure one’s time in asset-building contexts (e.g., education) or disadvantaged contexts (e.g., prison). This variation in time and exposure can contribute to racial inequities in life expectancy and other health outcomes across the life course and over generations. From crib to coffin, race is invented, recorded, and reported. The classification of people’s race on their birth certificates, college applications, medical charts, and death certificates highlights the central role of racial stratification in US society. 1,2 Racial classification follows one across the life course, and with this classification comes the potential for exposure to racism and health inequities. 3 A recent study suggested that in 2000, about 176 000 deaths were attributable to one specific form of racism, racial residential segregation. 4 Segregation, however, is but one type of inequality. 5 The complexity of the effects of racism over the course of development is insufficiently recognized. Most studies emphasize the main effect of a given exposure at a specific period in the life course. For instance, many studies demonstrate that the reporting of racial discrimination in childhood or adulthood is associated with illness. 6,7 A few studies go further, perhaps by specifying discrimination in multiple contexts (e.g., everyday discrimination vs workplace discrimination) 8,9 or by examining the interaction between discrimination and other factors, such as social strains. 10 However, a more complex and potentially more realistic model of racial health inequities can consider how race and racism intersect throughout the life course. The life course perspective emphasizes that one of the most important functions of age and time are not simply their biological and developmental significance, but also their social significance. 11 Eighteen-year-old persons do not simply have older organs than 17-year-old individuals; they also possess rights, roles, and obligations that 17-year-old individuals do not. These include (depending on place and historical time) the ability to drive, vote, marry, smoke cigarettes, drink alcohol, be sued, and hold a prison record. Each of these rights, roles, and obligations is potentially shaped by race and racism. 12 A life course perspective emphasizes the importance of change. Exposure to racism can change in nature, importance, and intensity. 13–15 Similarly, health and the factors that produce health can change. A growing body of research shows that health is not merely the result of risks that occur sporadically at one point in time. 16 Failure to attend to these temporal changes not only shortchanges our knowledge base, but also can lead to missed opportunities for intervention. The principles of the life course perspective have been well described in the literature. 11,16,17 We focus on a subset of ideas that may be particularly useful for studies of racial health inequities. They include the ideas of age-patterned exposures, sensitive periods, linked lives, latency periods, stress proliferation, historical period, and cohorts. These ideas are summarized in Table 1 and elaborated in the remainder of the article. TABLE 1— Description of Life Course Concepts Life Course Concept Definition Implications Age-patterned exposures (also termed “social pathways”) The pathways that individuals follow throughout the life course, which historical events can alter and social institutions can structure. 11 Accordingly, as individuals age, they exit some social institutions and enter new ones. Thus, exposure to discrimination within one social institution may reverberate across the life course and increase the risk of exposure to discrimination within other social institutions later in life. Prevalence of discrimination within certain settings (e.g., employment) is likely to vary over the life course. Racism researchers should consider tailoring measurement instruments to a given developmental stage and context. Sensitive period Certain events have a more profound effect on health when they are experienced during specific developmental stages. Outside of this period, the effect is much weaker. 18 Exposure to discrimination at certain developmental periods may have a greater effect on health than at other developmental periods. Studies should consider “age × exposure to discrimination” effects on health. Linked lives Events that affect one person also affect other persons in their network. 11,19 Thus, individuals are interdependent. Research on racism that focuses solely on the target of racism is missing important indirect effects of racism on others in the target’s social networks. Interventions against racism that are focused on a single individual are incomplete. Latency period The period between exposure and disease appearance. 20 Exposure to discrimination may have a longer latency period for physical health than for mental health. Short-term reactions (e.g., pulse rate, somatic symptoms) may or may not have long-term health outcomes. Stress proliferation Exposure to a single stressor may lead to additional secondary stressors. 21 Researchers must pay careful attention to whether a given factor is a confounder or mediator of the discrimination-health pathway. Period effect Historical events and social change affect individuals’ life course trajectories or pathways, but the effect is relatively uniform across birth cohorts. 11 Historical, racialized events can provide natural experiments from which to study the effects of discrimination on health. Cohort effect Historical events and social change differentially affect individuals’ life course trajectories or pathways across successive birth cohorts. 8 Historical, racialized events can provide natural experiments from which to study the differential effects of discrimination on health across generations. Open in a separate window