INTRODUCTION

Biological explanations do political work, writes anthropologist Margaret Lock, “creating the rules for belonging and exclusion” (Lock 1999, 83–113). Scientific criteria have long served as a means to create and justify social categories on the basis of “natural” distinctions. The biological sciences have been used to differentiate “good citizens” (those who, in a prevailing social context, will contribute to work, economic growth, and prosperity) from “bad citizens” (those who are criminally inclined, dependent, unhealthy, or likely to be costly risks). They have been used to identify membership in particular racial and ethnic groups for purposes of entitlements, and they have been used to explain inequalities by casting the differential treatment and status of particular groups as a natural consequence of essential, immutable traits.

The power of science as a means of categorizing people expanded in the late nineteenth century when clinicians and public health officials began to explore the etiology of disease in the distinctive features and susceptibilities of individual patients and their social milieu. Historian Matthew Jacobson describes how the increased focus on the individual had significant implications for many areas of social policy (Jacobson 1998, 113). Scientific fields such as craniometry and phrenology were developed to evaluate and categorize people according to their behavioral characteristics, susceptibility to disease, and ability to do particular types of work. They became tools in criminal investigations and provided guidelines for employment practices.