摘要：Objectives. To improve measurement of discrimination for health research, we sought to address the concern that explicit self-reports of racial discrimination may not capture unconscious cognition. Methods . We used 2 assessment tools in our Web-based study: a new application of the Implicit Association Test, a computer-based reaction-time test that measures the strength of association between an individual's self or group and being a victim or perpetrator of racial discrimination, and a validated explicit self-report measure of racial discrimination. Results . Among the 442 US-born non-Hispanic Black participants, the explicit and implicit measures, as hypothesized, were weakly correlated and tended to be independently associated with risk of hypertension among persons with less than a college degree. Adjustments for both measures eliminated the significantly greater risk for Blacks than for Whites (odds ratio = 1.4), reducing it to 1.1 (95% confidence interval = 0.7, 1.7). Conclusions . Our results suggest that the scientific rigor of research on racism and health will be improved by investigating how both unconscious and conscious mental awareness of having experienced discrimination matter for somatic and mental health. A small but fast-growing body of public health research is investigating the association between self-reported experiences of racial discrimination and population health. 1 – 5 To date, the strongest positive and generally linear associations have been observed for what are also the most commonly studied outcomes: self-reported psychological distress and self-reported health behaviors (e.g., smoking, alcohol use, and other drug use). 1 – 5 By contrast, evidence for somatic health outcomes, chiefly cardiovascular health, has been more mixed, with studies variously reporting linear, nonlinear, and no associations between self-reported experiences of discrimination and health status. 1 – 5 The largest published study on racial discrimination and risk of elevated blood pressure reported a positive linear (dose–response) relationship among professional Blacks but a curvilinear association among working-class Blacks, whose data revealed a J-shaped curve (i.e., blood pressure was higher among respondents reporting no discrimination than among those reporting moderate discrimination and highest among those reporting the most discrimination). 6 This phenomenon of a linear relationship among persons with more socioeconomic resources but a J-shaped curve among those with fewer has been replicated in other studies on self-reported discrimination and health. 7 , 8 One hypothesis that accounts for these results concerns what people are willing or able to say. 1 , 6 For persons with more socioeconomic resources, a response of no discrimination may more accurately capture the lack of personally experienced discrimination, whereas among persons with fewer socioeconomic resources, the same response may reflect an accurate report of no discrimination; a positive illusion, denial, or internalized oppression that is not consciously perceived; or a conscious decision not to report the discrimination because it is uncomfortable or dangerous to do so. 1 , 6 The latter 2 scenarios imply that a health risk may exist, via pathways involving physiological and behavioral responses to racial discrimination as a psychosocial stressor, 1 – 5 with bodies revealing health effects of exposures that can be subject to distortions in perceptions, memory, and rationalizations. 1 , 9 If so, reliance solely on self-report measures of racial discrimination, which has been standard to date, 1 – 5 may be problematic. 1 The need to critically assess measurement of exposure to discrimination is demonstrated by what psychologists term person–group discrimination discrepancy (PGDD). 10 – 15 It is well-documented that people typically report more discrimination for their group than for themselves personally, even though, statistically, the group level cannot be high if every individual's is low. PGDD is postulated to arise from an automatic protective mechanism, 16 reflecting a larger psychological tendency to view and present oneself positively, even when such denial may not be in one's ultimate self-interest. 17 – 19 During the past decade, social psychologists, borrowing basic methods of cognitive psychology, have developed a new approach—the Implicit Association Test (IAT), a computer-based reaction-time measure—to study phenomena for which self-report data might not fully capture what people think and feel. 20 – 23 An outgrowth of several decades of experimental research in the social, cognitive, clinical, and neuropsychological sciences concerned with the general architecture of the human mind, human learning, and unconscious mental processes, 20 , 24 – 28 the IAT is now one of the most robust and widely employed measures in social, cognitive, and even clinical psychology; it is used to assess the ease with which the mind makes associations. Building on the central finding that learning involves changes in neural function of different neurons that are active at the same time, the underlying cognitive principle is that concepts in the mind that are more closely associated with each other are more closely linked. These associations can occur both for conscious cognitive processes and for unconscious mental processes that lie beyond the reach of introspective access, with evidence indicating that implicit (unconscious) associations can form about many different phenomena—the self, other people, places, animals, memories, fantasies, inanimate objects, and nontangible ideas. 20 , 27 For example, an IAT could measure how much a person prefers flowers to bugs by contrasting the time it takes to make associations between the word pairs flowers and good and bugs and bad and then comparing what happens when participants are asked to pair flower with bad and bugs with good . A difference in average matching speed for opposite pairings determines the IAT score, a measure of strength of association. Participants are typically aware that they are making these connections but are unable to control them because of the rapid response times and the structure of the test. IAT methods are well-described in the social psychology literature, 21 , 22 and programming resources to develop IATs are available online. 29 To address extant questions about measuring experiences of discrimination, 1 – 5 , 30 , 31 we employed a novel application of the IAT to assess unconscious cognition about discrimination and consider the implications of using both explicit (self-report) and implicit measures for research on racism and health. Our work builds on and extends research that used the IAT to study racial prejudice and stereotypes. 32 – 35 Recent health-related studies found that the IAT for racial prejudice can predict physicians' clinical decisions. 36 , 37 Focusing on the somatic health of Black Americans, we hypothesized that the explicit and implicit measures would be weakly associated with each other (because of their varying abilities to measure unconscious processes) and independently associated with risk of hypertension (as modified by socioeconomic position) and with the greater hypertension risk among Blacks than Whites in the United States.
