Racial Differences in Early Cognitive and non-Cognitive Neurodevelopment in Brazil

Racial disparities in child development have been widely reported in several racially admixed countries.  In Brazil, the largest and most racially admixed country in South America, children of African ancestry have overall worse health outcomes than those of European ancestry.  These racial gaps are almost entirely explained by differences in demographic and socioeconomic characteristics and geographic location.  However, little is known about racial differences in early neurodevelopment, an important outcome and marker for future health.  In this paper, we investigate racial differences in several aspects of early neurodevelopment in Brazil and the mechanisms for these differences.  We employ a unique dataset for a sample of 412 healthy children aged 3 to 24 months who had normal birth outcomes (birth weight, gestational age, Apgar scores) and no major health problems.  The children were enrolled during routine well-child care visits to pediatric clinics attended by physicians affiliated with the study.  The study physicians were trained and calibrated in measuring infant neurodevelopment using a standardized instrument.  The physicians also interviewed the mothers about household demographic and socioeconomic characteristics and investments in child development.   We compare children of African ancestry alone and children of African ancestry with other ancestries to those of European ancestry alone in three regression specifications: A basic model controlling age and gender; a second model that adds household characteristics (maternal age, health, and marital status; numbers of child siblings and adults in household; maternal smoking during pregnancy; whether father and grandparent(s) are caregivers for the child; private health coverage; frequency of reading to the child, several playing activities, and watching TV); and a third model that adds geographic fixed effects.  Preliminary results indicate that children of African ancestry (alone or with other ancestries) lag significantly behind those of European ancestry on overall neurodevelopment and cognitive and receptive/expressive domains but not on neurological (gross/fine motor) domain.   The gaps are overall similar for African ancestry alone or mixed with other ancestries except for cognitive scores, which are lower for children of African ancestry alone.  Children of African ancestry alone are 21% more likely to score in a range indicative of high risk for neurodevelopment than those of European ancestry alone (18% for children of African ancestry with other ancestries).  Differences in household characteristics explain part of the gaps (up to 50% for total neurodevelopment score); geographic location explains the most of the remaining gaps and the entire gap in cognitive performance for both African ancestry groups.  Children of African ancestry alone score higher than those of European ancestry alone on the neurological domain controlling for household characteristics and geographic location.  The findings suggest that the large gaps in neurodevelopment by race in Brazil are entirely driven by social and geographic mechanisms that are largely related to racial differences in geographic location, highlighting the importance of policies to reduce residential segregation and improve social and economic environments.