A long time faculty member and researcher at the Escola de Sociologia e Política de São Paulo, he is known for his research on race in Brazil, particularly his years long studies on racial dynamics in the state of Bahia.
[4] His 1942 book, Negroes in Brazil, a Study of Race Contact at Bahia, based on his thesis, contains numerical tables classifying people based on race, and concluded that although Black people had occupied the lower ranks of the Brazilian social hierarchy, there was not racism as it had been defined in the United States.
His findings largely advanced the now-disproven racial democracy theory of Brazilian society, which posited that Brazilian society at large was not racist and societal inequities were defined by class rather than by race.
While at the Escola de Sociologia e Política de São Paulo, he coordinated research and studies, among the most notable being Cruz das Almas: A Brazilian Village (1951)[6] and O Homem no Vale do São Francisco (1972),[7][8] both part of his "community study" program, the first research program carried out by Pierson.
[11] He later was also named professor emeritus at the Faculty of Philosophy, Languages and Human Sciences, University of São Paulo in 1993.