Final answer:
Franz Boas taught that ethnocentrism leads to a lack of objectivity in scientific thinking, emphasizing cultural relativism and the unique development of each culture.
Step-by-step explanation:
True, Franz Boas did teach that ethnocentrism results in a lack of objectivity and impedes scientific thinking. Boas, who is considered the father of modern anthropology, pioneered the concept of cultural relativism. He challenged the ethnocentric and racist theories prevalent during his time, accentuating the idea that understanding other cultures requires an objective and scientific approach free from one's own cultural bias. Through his work, Boas emphasized the importance of collecting ethnographic data directly from the people being studied and recognized that cultures develop through unique historical trajectories influenced by interactions with others, rather than along some universal path deemed 'civilized' by Western standards.