In the humanities, one sense of culture, as an attribute of the individual, has been the degree to which they have cultivated a particular level of sophistication, in the arts, sciences, education, or manners. The level of cultural sophistication has also sometimes been seen to distinguish civilizations from less complex societies. Such hierarchical perspectives on culture are also found in class-based distinctions between a high culture of the social elite and a low culture, popular culture or folk culture of the lower classes, distinguished by the stratified access to cultural capital. In common parlance, culture is often used to refer specifically to the symbolic markers used by ethnic groups to distinguish themselves visibly from each other such as body modification, clothing or jewelry.[dubious – discuss] Mass culture refers to the mass-produced and mass mediated forms of consumer culture that emerged in the 20th century. Some schools of philosophy, such as Marxism and critical theory, have argued that culture is often used politically as a tool of the elites to manipulate the lower classes and create a false consciousness, such perspectives common in the discipline of cultural studies. In the wider social sciences, the theoretical perspective of cultural materialism holds that human symbolic culture arises from the material conditions of human life, as humans create the conditions for physical survival, and that the basis of culture is found in evolved biological dispositions.