Human cognition: Common principles and individual variation.

A core assumption in cognitive psychology is that common principles govern the functioning of human cognition. I argue that there may be such common principles, but people may use their cognition in different ways to perform the same task in the laboratory and in everyday life. There is a tendency in cognitive psychology research to focus on theories of tasks rather than theories of how the cognitive system might perform those tasks. This raises concerns about widespread reliance in cognitive psychology research on the aggregate data from participant groups, and how applicable theories of tasks are to understanding cognition outside of the laboratory. The concerns are illustrated in four areas of memory research:memory for serial order, mental imagery, cognitive aging, expertise and memory. It is proposed that advances in cognitive theory and applicability would benefit from more detailed exploration of the flexibility of human cognition during task performance.