The Heredity Matrix: Genetics and the Understanding of Mestizaje, Health, and Belonging in Mexico

Abstract 
Empirical data gathered from group discussions with Mexican undergraduate students from different regions and backgrounds showed that students tend to incorporate information about genetics into their accounts of hereditary intergenerational transmission linked to issues of family resemblance, health, and mestizaje (racial admixture) in a nuanced, elaborated, and non-simplistic manner. Locality and cultural variations can define the ways hereditary transmission is understood, which precludes any generalization about how genetics contributes to defining group or personal features. In the students’ accounts, gene action appears as stable but not deterministic, and they tend to sideline genetics and race, when dealing with identity-linked notions like mestizo. Genes were considered by students to be only one influence among many that affect their health, identity, family resemblance and ancestry. They understood themselves as hereditarily linked to their relatives, their communities, and their localities in what we call the proximate dimension of belonging. This contrasted with how they portrayed themselves in distant, more abstract belongings pertaining to ethnic, regional, or national ascriptions. This dual framing of genetic narratives was a main feature of a connected set of ideas about heredity and belonging, which can be elucidated through the concept of heredity matrix. This complements previous STS contributions to the research on Genetics in Society and Public Understanding of Science.