20th century, Mary Douglas thought that anthropology was about studying the meaning of material culture to the people who experience it. Marvin Harris, a contemporary of Douglas, put forward the theory of cultural materialism and said that all aspects of society have material causes. Sociology In archaeology, the idea that social relations are embodied in material is well known and established, with extensive research on exchange, gift giving and objects as part of social ceremonies and events. However, in contradiction to archaeology, where scientists build on material remains of previous cultures, sociology tends to overlook the importance of material in understanding relationships and human social behavior. The social aspects in material culture include the social behavior around it: the way that the material is used, shared, talked about, or made. An object cannot hold meaning in and of itself and so when one focuses on the social aspects of material culture, it is critical to keep in mind that interpretations of objects and of interactions with them are the ones to evoke importance and meaning. Heritage industry Museums and other material culture repositories, by their very nature, are often active participants in the heritage industry. Defined as "the business of managing places that are important to an area's history and encouraging people to visit them," the heritage industry relies heavily on material culture and objects to interpret cultural heritage. The industry is fueled by a cycle of people visiting museums, historic sites, and collections to interact with ideas or physical objects of the past. In turn, the institutions profit through monetary donations or admission fees as well as the publicity that comes with word-of-mouth communications. That relationship is controversial, as many believe that the heritage industry corrupts the meaning and importance of cultural objects. Often, scholars in the humanities take a critical view of the heritage industry, particularly heritage tourism, believing it to be a vulgar oversimplification and corruption of historic fact and importance. Others believe that the relationship and the financial stability it brings is often the element that allows curators, researchers, and directors to conserve material culture's legacy. Current production Some observers advocate intentionally altering the material cultures created by current civilizations. For example, waste reduction advocates within environmentalism advocate teaching design approaches, such as cradle-to-cradle design and appropriate technology. Anti-consumerism advocates encourage consuming less (thus creating fewer artifacts), engaging in more do-it-yourself projects and self-sufficiency (changing the