A cultural universal (also called an anthropological universal or human universal), as discussed by Emile Durkheim, George Murdock, Claude Lévi-Strauss, Donald Brown and others, is an element, pattern, trait, or institution that is common to all human cultures worldwide. Taken together, the whole body of cultural universals is known as the human condition. Evolutionary psychologists hold that behaviors or traits that occur universally in all cultures are good candidates for evolutionary adaptations. Some anthropological and sociological theorists that take a cultural relativist perspective may deny the existence of cultural universals: the extent to which these universals are "cultural" in the narrow sense, or in fact biologically inherited behavior is an issue of "nature versus nurture".
In his book Human Universals (1991), Donald Brown defines human universals as comprising "those features of culture, society, language, behavior, and psyche for which there are no known exception", providing a list of hundreds of items he suggests as universal. Among the cultural universals listed by Donald Brown are:
The observation of the same or similar behavior in different cultures does not prove that they are the results of a common underlying psychological mechanism. One possibility is that they may have been invented independently due to a common practical problem.
Since any cultures that have been studied by anthropologists have had contact with at least the anthropologists that studied it, and anthropological research ethics slows the studies down so that other groups unbound by such ethics, often at least locally represented by people of the same skin color as the supposedly isolated tribe but significantly culturally globalized, reach the tribe before the anthropologists do, no truly uncontacted culture has ever been scientifically studied. This allows outside influence to be an explanation for cultural universals as well. This does not preclude multiple independent inventions of civilization and is therefore not the same thing as hyperdiffusionism, it merely means that cultural universals are not proof of innateness.
Anthropology's application of one ordinary evidence standard for data that agrees with its theories of cultural universals and one extraordinary standard of evidence for data that disagree with it raises issues with population level publication bias. While it is possible with strong enough evidence for the validity of one case study that disagree to pass peer review, those that agree will statistically do so more often than those that disagree even if the level of evidence is the same. Since multiple field studies regarding the same culture are combined when statistical prevalences of behaviors are assessed, the result may cause appearances of behaviors having a supposedly universal statistical demographic even if it does not. Some anthropologists suggest that this may give an appearance of statistics such as more men than women hunting large prey being universal without actually being universal, for example that field studies in which more men than women hunted passed peer review while field studies for the same culture in which the genders were equal or inverted for hunting were not published.