Anthropology's basic concerns are "What defines Homo sapiens?", "Who are the ancestors of modern Homo sapiens?", "What are humans' physical traits?", "How do humans behave?", "Why are there variations and differences among different groups of humans?", "How has the evolutionary past of Homo sapiens influenced its social organization and culture?" and so forth.
In the United States, contemporary anthropology is typically divided into four sub-fields: cultural anthropology also known as social anthropology, archaeology, linguistic anthropology, and physical (or biological) anthropology.[3] The four-field approach to anthropology is reflected in many undergraduate textbooks[4] as well as anthropology programs (e.g. Michigan, Berkeley, Penn). At universities in the United Kingdom, and much of Europe, these "sub-fields" are frequently housed in separate departments and are seen as distinct disciplines.[5]
The social and cultural sub-field has been heavily influenced by structuralist and post-modern theories, as well as a shift toward the analysis of modern societies (an arena more typically in the remit of sociologists). During the 1970s and 1990s there was an epistemological shift away from the positivist traditions that had largely informed the discipline.[6] During this shift, enduring questions about the nature and production of knowledge came to occupy a central place in cultural and social anthropology. In contrast, archaeology, biological anthropology, and linguistic anthropology remained largely positivist. Due to this difference in epistemology, anthropology as a discipline has lacked cohesion over the last several decades. This has even led to departments diverging, for example in the 1998–9 academic year at Stanford University, where the "scientists" and "non-scientists" divided into two departments: anthropological sciences and cultural & social anthropology;[7] these departments later reunified in the 2008–9 academic year.[8]