This work investigates the biological and sociological factors that define Jewish identity in the context of race and environmental influence. Maurice Fishberg, a physician and anthropologist, utilizes anthropometric data and demographic statistics from the early 20th century to challenge contemporary racial theories. He argues that the physical characteristics of Jewish populations are primarily the result of environmental adaptation and social isolation rather than inherent racial purity or biological distinctiveness.

Experts recognize this text as a significant early 20th-century contribution to the debate on Jewish identity and the critique of racial essentialism. Readers frequently note the academic density of the prose and the historical importance of Fishberg's empirical approach to social anthropology.