In the 1940s the Boasian understanding of culture was challenged by a new paradigm for anthropological and social science research called Structural functionalism. This paradigm developed independently but in parallel in both the United Kingdom and in the United States (In both cases it is sui generis: it has no direct relationship to "structuralism" except that both French structuralism and Anglo-American Structural-Functionalism were all influenced by Durkheim. It is also analogous, but unrelated to, other forms of "functionalism"). Whereas the Boasians viewed anthropology as that natural science dedicated to the study of humankind, structural functionalists viewed anthropology as one social science among many, dedicated to the study of one specific facet of humanity. This led structural-functionalists to redefine and minimize the scope of "culture."

In the United Kingdom, the creation of structural functionalism was anticipated by Raymond Firth's (1901–2002) We the Tikopia, published in 1936, and marked by the publication of African Political Systems, edited by Meyer Fortes (1906–1983) and E.E. Evans-Pritchard (1902–1973) in 1940.^[137][138] In these works these anthropologists forwarded a synthesis of the ideas of their mentor, Bronisław Malinowski (1884–1942), and his rival, A. R. Radcliffe-Brown (1881–1955). Both Malinowski and Radcliffe-Brown viewed anthropology—what they call "social anthropology"—as that branch of sociology that studied so-called primitive societies. According to Malinowski's theory of functionalism, all human beings have certain biological needs, such as the need for food and shelter, and humankind has the biological need to reproduce. Every society develops its own institutions, which function to fulfill these needs. In order for these institutions to function, individuals take on particular social roles that regulate how they act and interact. Although members of any given society may not understand the ultimate functions of their roles and institutions, an ethnographer can develop a model of these functions through the careful observation of social life.^[139] Radcliffe-Brown rejected Malinowski's notion of function, and believed that a general theory of primitive social life could only be built up through the careful comparison of different societies. Influenced by the work of French sociologist Émile Durkheim(1858–1917), who argued that primitive and modern societies are distinguished by distinct social structures, Radcliffe-Brown argued that anthropologists first had to map out the social structure of any given society before comparing the structures of different societies.^[140] Firth, Fortes, and Evans-Pritchard found it easy to combine Malinowski's attention to social roles and institutions with Radcliffe-Brown's concern with social structures. They distinguished between "social organization" (observable social interactions) and "social structure" (rule-governed patterns of social interaction), and shifted their attention from biological functions to social functions. For example, how different institutions are functionally integrated, and the extent to, and ways in, which institutions function to promote social solidarity and stability. In short, instead of culture (understood as all human non-genetic or extra-somatic phenomena) they made "sociality" (interactions and relationships among persons and groups of people) their object of study. (Indeed, Radcliffe-Brown once wrote "I should like to invoke a taboo on the word culture.")^[141]

Coincidentally, in 1946 sociologist Talcott Parsons (1902–1979) founded the Department of Social Relations at Harvard University. Influenced by such European sociologists as Émile Durkheim and Max Weber, Parsons developed a theory of social action that was closer to British social anthropology than to Boas's American anthropology, and which he also called "structural functionalism." Parson's intention was to develop a total theory of social action (why people act as they do), and to develop at Harvard and inter-disciplinary program that would direct research according to this theory. His model explained human action as the result of four systems:

According to this theory, the second system was the proper object of study for psychologists; the third system for sociologists, and the fourth system for cultural anthropologists.^[142][143] Whereas the Boasians considered all of these systems to be objects of study by anthropologists, and "personality" and "status and role" to be as much a part of "culture" as "norms and values," Parsons envisioned a much narrower role for anthropology and a much narrower definition of culture.

Although Boasian cultural anthropologists were interested in norms and values, among many other things, it was only with the rise of structural functionalism that people came to identify "culture" with "norms and values." Many American anthropologists rejected this view of culture (and by implication, anthropology). In 1980, anthropologist Eric Wolf wrote,

Nevertheless, several of Talcott Parsons' students emerged as leading American anthropologists. At the same time, many American anthropologists had a high regard for the research produced by social anthropologists in the 1940s and 1950s, and found structural-functionalism to provide a very useful model for conducting ethnographic research.

The combination of American cultural anthropology theory with British social anthropology methods has led to some confusion between the concepts of "society" and "culture." For most anthropologists, these are distinct concepts. Society refers to a group of people; culture refers to a pan-human capacity and the totality of non-genetic human phenomena. Societies are often clearly bounded; cultural traits are often mobile, and cultural boundaries, such as they are, can be typically porous, permeable, and plural.^[145] During the 1950s and 1960s anthropologists often worked in places where social and cultural boundaries coincided, thus obscuring the distinction. When disjunctures between these boundaries become highly salient, for example during the period of European de-colonization of Africa in the 1960s and 1970s, or during the post-Bretton Woods realignment of globalization, however, the difference often becomes central to anthropological debates.^{[146][147][148][149][150]}