Dr. Bela Hubbard, in "The Hybrid Race Doctrine":
... the Barbadian Negro displays mental stability and strength of character in marked contrast to the hybrid Negroes of neighbouring islands. ... On such occasions as a storm at sea or a brush with Motilone Indians in the jungle, it was invariably the Barbadian Negroes who displayed the greater stamina and courage.
While in Trinidad, Hubbard asked the chief of police why pure Negroes figured so heavily on his force:
He explained that although there were no racial qualifications, Mulattoes rarely passed the rigorous physical examination...