Aside from publications based on ethnographic field research he has written theoretical works about political leadership and systems, ethnicity, cultural evolution.
Since the late 1990s he has published extensively about the history of anthropology, much of it offering new insights into the work and thought of Franz Boas.
Although born across the Hudson River in New Jersey he grew up in several communities around New York City, spending his high school years in Lynbrook on Long Island.
In the 1970s and 1980s, Lewis studied ethnicity, class, and culture change in Israel, focusing on those Jews who immigrated from Yemen and Morocco.
Contrary to the stereotype of the Yemenites as downtrodden and rather poor "Oriental" Jews (mizrachim in current usage) Lewis's evidence showed them to be confident, increasingly successful in status (occupation, education, political presence), as well as maintaining and developing aspects of their music, dance, arts, and persistent in the orthodox Jewish religious belief and practices they brought with them from Yemen.
This work responds critically to these critiques, offering evidence to counter the widespread notion of anthropology as the handmaiden of colonialism, and of its liability for exoticizing and otherwise misrepresenting what post-1960s writers call "the Other."
"Adapt Fully to Their Customs": Franz Boas as an Ethnographer among the Inuit of Baffinland (1883-84) and His Monograph The Central Eskimo (1888).