Metacognition is defined as "cognition about cognition", or "knowing about knowing."[1] It can take many forms; "it includes knowledge about when and where to use particular strategies for learning or for problem solving."[1] "Metamemory, individuals' knowledge about memory, is an especially important form of metacognition."[1] Differences in metacognitive processing across cultures have not been widely studied, but could provide better outcomes in cross- cultural learning between teachers and students.[2] Some evolutionary psychologists hypothesize that metacognition is used as a survival tool, which would make metacognition the same across cultures.[2] Writings on metacognition can be traced back at least as far as De Anima and the Parva Naturalia of the Greek philosopher Aristotle.[3]