Racism May Interrupt Age-related Brain Growth of African American Children in the United States.

BACKGROUND: Considerable research has documented age-related growth in brain size as a marker of normal brain development. This is particularly important because brain volume has a significant role in overall cognitive performance. However, less research is done on whether age-related changes in the global brain volume differ across diverse racial and ethnic groups. We hypothesized that age-related growth in brain size would be disrupted in African American children who are historically affected by racism. PURPOSE: Considering race as a proxy of racism rather than genetics, this study tested racial and ethnic differences in the effects of age on global brain volume using structural brain imaging data. Built on a sociological, rather than a biological theory, we built our study on Marginalization-related Diminished Returns (MDRs) framework, which argues that under racism, resources and assets are less effective for social groups that are historically racialized, discriminated against, marginalized, and segregated. Considering age as an asset/resource that increases the global brain volume, we expected weaker effects of age on overall brain size of African American and Hispanic children, than White and non-Hispanic children, again as a result of racism. METHODS: We borrowed the structural Magnetic Resonance Imaging (sMRI) data from the Children Brain Cognitive Development (ABCD) study, which included 9,311 9-10 year old children. The independent variable was the child's age treated as a continuous measure (in months). The primary outcome was global brain volume. Sex, parental employment, parental education, household income, and parental marital status were the covariates. Race and ethnicity, as proxies of racism, were the moderators. To analyze the data, we used linear regression models. RESULTS: Age was positively associated with the global brain size in children. In line with the MDRs, the positive association between age and global brain volume was weaker for African American than White children, while family structure, sex, and family socioeconomic status was controlled. CONCLUSIONS: Under racism, age has unequal effects on global brain size of diverse racial groups. In line with the MDRs, we observe diminished age-related growth of the brain for African American children, which documents detrimental effects of racism. For White children who are not affected by racism, age makes a large difference regarding global brain volume. Age-related growth of global brain size is diminished in African American children, whose daily lives are shaped by racism. School and residential segregation may have a role in reducing the effect of age on children's brain growth in African American families. The results should not be interpreted as inferiority of one group but social processes that hinder normal development of a historically oppressed group.

Maternal Education at Birth and Youth Breakfast Consumption at Age 15: Blacks' Diminished Returns.

BACKGROUND: Based on the Marginalization-related Diminished Returns (MDRs) framework, high socioeconomic status (SES) such as parental education shows weaker effects for Blacks than Whites. For example, high SES Black individuals report a high level of depression, anxiety, suicide, chronic disease, smoking, and mortality. Limited knowledge exists on MDRs of parental education on dietary behavior. AIMS: Built on the MDRs framework, we tested the hypothesis of whether the effect of parental education on eating breakfast differs for Black compared to White families. We hypothesized that there is an association between mothers' educational attainment and eating breakfast and compared Blacks and Whites for the effect of mothers' educational attainment on the frequency of eating breakfast. METHODS: The Fragile Families and Child Wellbeing Study is a 15-year follow up study of a random sample of births in cities larger than 200,000 population. The predictor was parental education at birth. The outcome was the frequency of eating breakfast at age 15. Linear regression was used for data analysis. RESULTS: Maternal educational attainment at birth was positively associated with youth frequency of eating breakfast among Whites, not Blacks. We also found a significant interaction between maternal educational attainment at birth and race, suggesting that the association between maternal education and youth frequency of eating breakfast at age 15 was weaker for Black than White families. CONCLUSIONS: Diminished returns of maternal educational attainment on healthy youth diet may contribute to the racial disparities in poor health of high SES Black families. That is, a smaller protective effect of maternal education on changing health behaviors for Black than White youth may be one of the mechanisms by which health is worse than expected in high SES Black families. The health disparities are not only due to racial differences in SES but also the diminishing returns of socioeconomic status indicators such as education for racial minorities. Research should study contextual and structural factors that reduce Black families' ability to mobilize their human capital and secure health outcomes in urban settings.

Family Income and Gang Presence in the Neighborhood: Diminished Returns of Black Families.

BACKGROUND: Based on the Minorities' Diminished Returns (MDRs) framework, indicators of high socioeconomic status, such as higher family income, show weaker protective effects on various developmental, behavioral, and health outcomes for Black than White families. As a result of these MDRs, Black families who access education and income still report high levels of depression, smoking, obesity, and chronic disease. Limited knowledge exists on MDRs of income on neighborhood quality. AIMS: Built on the MDRs framework, this study tested the hypothesis of whether the effect of family income and maternal education at birth on neighborhood gang presence varies between Black and White families. The hypotheses were that: (1) higher income families would report lower gang presence in their neighborhood, and (2) compared to Whites, Blacks would show weaker protective effects of family income on gang presence in their neighborhood. METHODS: The Fragile Families and Child Wellbeing Study is a 15-year follow up study of a random sample of births in cities with larger than 200,000 population. Two thousand nine hundred and nineteen White or Black families were included and were followed from birth of their child for 15 years. The predictors were family income and maternal education at birth, treated as categorical variables. The outcome was gang presence in the neighborhood at age 15. Logistic regression was used for data analysis. RESULTS: Higher maternal education at birth was inversely associated with gang presence in the neighborhoods, while family income at birth did not show an effect on reducing gang presence in the neighborhood at age 15. Family income at birth and race interact, suggesting that the association between family income at birth and gang presence in the neighborhood at age 15 was weaker for Black than White families. Our race-stratified models also showed an inverse effect of family income at birth on gang presence in the neighborhood at age 15 in White but not Black families. CONCLUSIONS: Diminished returns of family income at birth on neighborhood safety and social disorder may be a mechanism that contributes to racial health disparities in higher socioeconomic status and also poor outcomes for Black families across socioeconomic status (SES) levels. That is, a smaller protective effect of family income on changing the real lives of Black compared to White families may be one of the mechanisms by which health is worse than expected in Black families, across the entire SES spectrum. The health, behavioral, and developmental disparities are not only due to the racial gap in SES but also diminishing returns of socioeconomic status indicators such as family income for racial minorities. Research should study contextual and structural factors that reduce Black families' ability to mobilize their human capital and secure health outcomes in urban settings.

Unequal Protective Effects of Parental Educational Attainment on the Body Mass Index of Black and White Youth.

BACKGROUND: Parental educational attainment is shown to be protective against health problems; the Minorities' Diminished Returns theory, however, posits that these protective effects tend to be smaller for socially marginalized groups particularly blacks than whites. AIMS: To explore racial differences in the effect of parental educational attainment on body mass index (BMI) in a national sample of US adolescents. METHODS: In this cross-sectional study, we used baseline data of 10,701 (8678 white and 2023 black) 12-17 years old adolescents in the Population Assessment of Tobacco and Health (PATH; 2013). Parental educational attainment was the predictor. Youth BMI (based on self-reported weight and height) was the dependent variable. Age, gender, ethnicity, and family structure were covariates. Race was the focal moderator. RESULTS: Overall, higher parental educational attainment was associated with lower youth BMI. Race, however, moderated the effect of parental educational attainment on BMI, suggesting that the protective effect of parental educational attainment on BMI is significantly smaller for black than white youth. CONCLUSIONS: In the United States, race alters the health gains that are expected to follow parental educational attainment. While white youth who are from highly educated families are fit, black youth have high BMI at all levels of parental educational attainment. This means, while the most socially privileged group, whites, gain the most health from their parental education, blacks, the least privileged group, gain the least. Economic, social, public, and health policymakers should be aware that health disparities are not all due to lower socioeconomic status (SES) of the disadvantaged group but also diminished returns of SES resources for them. Black-white health disparities exist across all high socioeconomic status (SES) levels.

Family Socioeconomic Status at Birth and Youth Impulsivity at Age 15; Blacks' Diminished Return.

Minorities’ Diminished Return theory suggests that health effects of socioeconomic status (SES) are systemically smaller for racial and ethnic minorities compared to Whites. To test the relevance of Minorities’ Diminished Return theory for youth impulsivity, we investigated Black⁻White differences in the effects of family SES at birth on subsequent youth impulsivity at age 15. Data came from the Fragile Families and Child Wellbeing Study (FFCWS), 1998⁻2016, a 15-year longitudinal study of urban families from the birth of their children to age 15. This analysis included 1931 families who were either White (n = 495) or Black (n = 1436). The independent variables of this study were family income, maternal education, and family structure at birth. Youth impulsivity at age 15 was the dependent variable. Gender was the covariate and race was the focal moderator. We ran linear regressions in the overall sample and specific to each race. In the overall sample, higher household income (b = −0.01, 95% CI = −0.01 to 0.00) and maternal education (b = −0.24, 95% CI = −0.44 to −0.04) at birth were associated with lower youth impulsivity at age 15, independent of race, gender, and family structure. A significant interaction was found between race and household income at birth (b = 0.01, 95% CI = 0.00 to 0.02) on subsequent youth impulsivity, which was indicative of a stronger protective effect for Whites compared to Blacks. Blacks’ diminished return exists for the long-term protective effects of family income at birth against subsequent youth impulsivity. The relative disadvantage of Blacks in comparison to Whites is in line with a growing literature showing that Black families gain less from high SES, which is possibly due to the existing structural racism in the US.