The Genetic Reification of “Race”?: A Story of Two Mathematical Methods

Two families of mathematical methods lie at the heart of investigating the hierarchical structure of genetic variation in Homo sapiens: diversity partitioning, which assesses genetic variation within and among predetermined groups, and clustering analysis, which simultaneously produces clusters and assigns individuals to these “unsupervised” cluster classifications. While mathematically consistent, these two methodologies are understood by many to ground diametrically opposed claims about the reality of human races. Moreover, modeling results are sensitive to assumptions such as preexisting theoretical commitments to certain linguistic, anthropological, and geographic human groups. Thus, models can be perniciously reified. That is, they can be conflated and confused with the world. This fact belies standard realist and antirealist interpretations of “race,” and supports a pluralist conventionalist interpretation.