The Ecological Cognition perspective emphasizes the fact that human cognition is adaptive to the constraints of the context of task performance. People are good at developing strategies for task performance that take advantage of the informational affordances of the task environment. Therefore, if we wish to understand human cognition, we must look beyond the skin and skull of the individual to the material and social structures with which the mind interacts. Of course, material artifacts and social arrangements are elements of adaptive processes as well. Material artifacts are often crystallizations of regularities in the task environment and they develop over time, changing adaptively to fit the constraints of the task, the properties of the task performers, and the other artifacts employed in the task performance. Such changes in the material artifacts change the informational affordances of the task environment, which creates new opportunities for the development of strategies. Thus, human cognition and the material supports of human cognition must be seen as a co-adaptive system. Similarly, in complex work settings where two or more persons jointly perform tasks, social arrangements are enacted anew each time a socially distributed task is performed. Strategies for the social division of cognitive labor are also part of this co-adaptive system, both constraining and being constrained by mental and material artifacts. These interlocked co-adaptive systems suggest a cognitive ecology. It's a compelling way of talking about such systems. Can it be more than a metaphor?