Final answer:
Franz Boas did not call for a moratorium in the usual sense of the word; instead, he opposed racial theories in anthropology, emphasizing that environmental factors influenced physical characteristics. His work advocated for understanding cultural development as a unique and complex process, not attributable to biological differences.
Step-by-step explanation:
Franz Boas, a pioneering anthropologist, did not directly call for a moratorium in the sense of a temporary prohibition as commonly understood today. Instead, Boas ardently opposed ethnocentric and racist theories within anthropology. However, the term moratorium often appears within the context of historical events, such as President Hoover's Hoover Moratorium in 1931, which called for a halt to World War I reparations payments. Boas' work itself profoundly challenged racist methodologies and the measurement of skulls to support white supremacist theories, asserting those physical characteristics were largely influenced by environmental factors rather than being indicators of intellect or cultural attainment.
Boas championed the idea that cultures developed uniquely and were influenced by a multitude of factors, a concept that undermined theories used to justify racism and ethnocentrism. He put forth the idea that biological differences played no role in cultural, language, or achievement differences, effectively arguing for a conceptual moratorium on the use of anthropology to support such discriminatory practices.