Abstract

Certain traits, such as intelligence and mental deficiency, have been the focus of eugenic research and propaganda. This focus on such eugenic traits builds on three commonsense ideas: (1) People differ with respect to some of their traits, such as eye-colour and height; (2) Many traits run in families, being passed on from parents to their children; (3) Some traits are desirable, while others are undesirable. These three ideas about traits—their variability, heritability, and desirability—fed the much more controversial eugenicist view that some traits make a person of “good stock”, while others reflect the fact that she comes from “inferior stock”. In combination with the power to influence human reproduction, the systematic study of eugenic traits has thus been thought to provide the basis for human improvement across generations. Three sources reveal which traits were considered important to eugenicists, the public, and decision makers: the research publications of eugenicists, discussions of eugenics in public and popular media, and legislation.