There is no one approach to archaeological theory that has been adhered to by all archaeologists. When archaeology developed in the late 19th century, the first approach to archaeological theory to be practiced was that of cultural-history archaeology , which held the goal of explaining why cultures changed and adapted rather than just highlighting the fact that they did, therefore emphasizing historical particularism .  In the early 20th century, many archaeologists who studied past societies with direct continuing links to existing ones (such as those of Native Americans , Siberians , Mesoamericans etc.) followed the direct historical approach , compared the continuity between the past and contemporary ethnic and cultural groups.  In the 1960s, an archaeological movement largely led by American archaeologists like Lewis Binford and Kent Flannery arose that rebelled against the established cultural-history archaeology.   They proposed a "New Archaeology", which would be more "scientific" and "anthropological", with hypothesis testing and the scientific method very important parts of what became known as processual archaeology .