Since the work of Franz Boas and Bronisław Malinowski in the late 19th and early 20th centuries, social anthropology has been distinguished from other social science disciplines by its emphasis on in-depth examination of context, cross-cultural comparisons (socio-cultural anthropology is by nature a comparative discipline), and the importance it places on long-term, experiential immersion in the area of research, often known as participant-observation. Cultural anthropology in particular has emphasized cultural relativity and the use of findings to frame cultural critiques. This has been particularly prominent in the United States, from Boas's arguments against 19th-century racial ideology, through Margaret Mead's advocacy for gender equality and sexual liberation, to current criticisms of post-colonial oppression and promotion of multiculturalism.

Principally in the United States, anthropology is often defined as being "holistic" and based on a "four-field" approach. There is an ongoing dispute on this view; supporters consider anthropology holistic in two senses: it is concerned with all human beings across times and places, and with all dimensions of humanity (evolutionary, biophysical, sociopolitical, economic, cultural, psychological, etc.); also many academic programs following this approach take a "four-field" approach to anthropology that encompasses physical anthropology, archeology, linguistics, and cultural anthropology or social anthropology. The definition of anthropology as holistic and the "four-field" approach are disputed by some leading anthropologists, that consider those as artifacts from 19th century social evolutionary thought that inappropriately impose scientific positivism upon cultural anthropology. While originating in the US, both the four field approach and debates concerning it have been exported internationally under American academic influence.

The four fields are:

Biological or physical anthropology seeks to understand the physical human being through the study of human evolution and adaptability, population genetics, and primatology. Subfields or related fields include anthropometrics, forensic anthropology, osteology, and nutritional anthropology.

Socio-cultural anthropology is the investigation, often through long term, intensive field studies (including participant-observation methods), of the culture and social organization of a particular people: language, economic and political organization, law and conflict resolution, patterns of consumption and exchange, kinship and family structure, gender relations, childrearing and socialization, religion, mythology, symbolism, etc. (U.S. universities more often use the term cultural anthropology; British universities have tended to call the corresponding field social anthropology, and for much of the 20th century emphasized the analysis of social organization more than cultural symbolism.) In some European countries, socio-cultural anthropology is known as ethnology (a term also used in English-speaking countries to denote the comparative aspect of socio-cultural anthropology.) Subfields and related fields include psychological anthropology, folklore, anthropology of religion, ethnic studies, cultural studies, anthropology of media and cyberspace, and study of the diffusion of social practices and cultural forms.

Linguistic anthropology seeks to understand the processes of human communications, verbal and non-verbal, variation in language across time and space, the social uses of language, and the relationship between language and culture. It is the branch of anthropology that brings linguistic methods to bear on anthropological problems, linking the analysis of linguistic forms and processes to the interpretation of sociocultural processes. Linguistic anthropologists often draw on related fields including anthropological linguistics, sociolinguistics, cognitive linguistics, semiotics, discourse analysis, and narrative analysis.

Archaeology studies the contemporary distribution and form of artifacts (materials modified by past human activities), with the intent of understanding distribution and movement of ancient populations, development of human social organization, and relationships among contemporary populations; it also contributes significantly to the work of population geneticists, historical linguists, and many historians. Archaeology involves a wide variety of field techniques (remote sensing, survey, geophysical studies, coring, excavation) and laboratory procedures (compositional analyses, dating studies (radiocarbon, optically stimulated luminescence dating), measures of formal variability, examination of wear patterns, residue analyses, etc.). Archaeologists predominantly study materials produced by prehistoric groups but also includes modern, historical and ethnographic populations. Archaeology is usually regarded as a separate (but related) field outside North America, although closely related to the anthropological field of material culture, which deals with physical objects created or used within a living or past group as a means of understanding its cultural values.