Metacognition refers to the awareness an individual has of their own mental processes (also referred to as 'thinking about thinking'). In the past thirty years metacognition research has become a rapidly growing field of interdisciplinary research within the cognitive sciences. Just recently, there have been major changes in this field, stimulated by the controversial issues of metacognition in nonhuman animals and in early infancy. Consequently the question what defines a metacognitive process has become a matter of debate: how should one distinguish between simple minds that are not yet...