Anthropology began as a hobby for 19th century scholars who wrote travel diaries commenting on other cultures without conducting fieldwork. Early anthropologists constructed theories of cultural evolution to explain differences but later emphasized understanding each culture on its own terms through first-hand data collection. Bronislaw Malinowski established participant observation as the method for fieldwork in the early 20th century. Leslie White and Julian Steward viewed culture as adapting to the environment and harnessing resources. Modern anthropology utilizes both scientific approaches that see culture as adapting to the environment and humanistic approaches that emphasize cultural uniqueness. Ideational perspectives focus on ideas and symbols shaping behavior, while adaptive perspectives emphasize technology, ecology, demography and economics.