Ellen criticizes Steward's culture core and Harris's structural determinism because of their mono-directional causality. To disregard the possibility of multi-directional causality is to ignore the complexities of a cultural system. Moreover, Ellen argues that Steward's culture core is a nebulous concept at best. He adds that by neglecting social history, Steward leaves little room for human intention to be included in his equation, ultimately leaching more subtleties and complexities out of his final cultural description. Cultural Ecology and the explanatory imperative.
Cultural ecology analyzes the interrelationship of environment, subsistence, and society.
The study of interrelationships involves understanding adaptation, which means that change is an essential part of cultural ecology. Heider describes cultural ecology's approach as holistic. This is because it looks for systematic interrelationships between environment, subsistence, and society and its research strategy involves understanding the general principles underlying specific systems. Heider then proceeds to show how a single example can be misleading. The search for general principles can also have similar problems.