Culture as a mediator of gene-environment interaction: Cultural consonance, childhood adversity, a 2A serotonin receptor polymorphism, and depression in urban Brazil.

Research on gene-environment interaction was facilitated by breakthroughs in molecular biology in the late 20th century, especially in the study of mental health. There is a reliable interaction between candidate genes for depression and childhood adversity in relation to mental health outcomes. The aim of this paper is to explore the role of culture in this process in an urban community in Brazil. The specific cultural factor examined is cultural consonance, or the degree to which individuals are able to successfully incorporate salient cultural models into their own beliefs and behaviors. It was hypothesized that cultural consonance in family life would mediate the interaction of genotype and childhood adversity. In a study of 402 adult Brazilians from diverse socioeconomic backgrounds, conducted from 2011 to 2014, the interaction of reported childhood adversity and a polymorphism in the 2A serotonin receptor was associated with higher depressive symptoms. Further analysis showed that the gene-environment interaction was mediated by cultural consonance in family life, and that these effects were more pronounced in lower social class neighborhoods. The findings reinforce the role of the serotonergic system in the regulation of stress response and learning and memory, and how these processes in turn interact with environmental events and circumstances. Furthermore, these results suggest that gene-environment interaction models should incorporate a wider range of environmental experience and more complex pathways to better understand how genes and the environment combine to influence mental health outcomes.

Cultural consonance and arterial blood pressure in urban Brazil.

In previous research in Brazil, we tested the hypothesis that cultural consonance is associated with arterial blood pressure. Cultural consonance is the degree to which individuals are able to approximate in their own behaviors the prototypes for behavior encoded in shared cultural models. Individuals who had higher cultural consonance in the domains of lifestyle and social support had lower blood pressures. The aim of the current research was to replicate and extend these findings. First, a more extensive cultural domain analysis was carried out, improving the description of cultural models. Second, more sensitive measures of cultural consonance were developed. Third, data were collected in the same community studied previously. The following findings emerged: (a) cultural domain analysis (using a mix of quantitative and qualitative techniques) indicated that cultural models for these domains are widely shared within the community; (b) the associations of cultural consonance in these domains with arterial blood pressure were replicated; and, (c) the pattern of the associations differed slightly from that observed in earlier research. This pattern of associations can be understood in terms of macrosocial influences over the past ten years. The results support the importance of long-term fieldwork in anthropology.