The dual concepts of mindfulness and mindlessness are described. Mindfulness is a state of conscious awareness in which the individual is implicitly aware of the context and content of information. It is a state of openness to novelty in which the individual actively constructs categories and distinctions. In contrast, mindlessness is a state of mind characterized by an over reliance on categories and distinctions drawn in the past and in which the individual is context-dependent and, as such, is oblivious to (...) novel aspects of the situation. Mindlessness is compared to more familiar concepts such as habit, functional fixedness, overlearning, and automatic processing. Like mindlessness, these concepts concern rigid invariant behavior that occurs with little or no conscious awareness. The primary difference is that mindlessness may result from a single exposure to information. When information is given in absolute language, is given by an authority, or initially appears irrelevant, there is little manifest reason to critically examine the information and thereby recognize the ways it may be context-dependent. Instead, the individual mindlessly forms a cognitive commitment to the information and freezes its potential meaning. Alternative meanings or uses of the information become unavailable for active cognitive use. Automatic vs controlled processing, while seemingly most similar to mindlessness/mindfulness, are orthogonal to them. One can process information in a controlled but mindless manner, or automatic but mindful. Related concepts like scripts, set, expectancy, labels, and roles direct behavior, but these too may be enacted mindlessly or mindfully. The major consequences of mindlessness/mindfulness are discussed with respect to their relevance for overt behavior , memory, and health. Finally, the relationship between traditional notions of consciousness and mindfulness is briefly examined. (shrink)