This is a very recent paper from Chris Frith that was published in Philosophical Transactions of the Royal Society of Biological Sciences. This is one article (Creative Commons) from the Theme Issue 'New thinking: the evolution of human cognition' compiled and edited by Cecilia Heyes and Uta Frith - the rest are behind a pay-wall.
From his Google Site:
Chris Frith was born in Cross-in-Hand, Sussex in 1942. He grew up in London and Yorkshire and studied Natural Sciences at Cambridge University. He trained in clinical psychology at the University of London's Institute of Psychiatry and completed his PhD in experimental psychology, supervised by Hans Eysenck, in 1969. Chris married Uta Aurnhammer in 1966. Their sons Martin and Alex were born in 1975 and 1978.Here is the beginning of this very interesting paper.
Chris Frith was a staff scientist of the Medical Research Council from 1975 to 1994. While with the MRC he worked on the biological basis of schizophrenia in Tim Crow's unit at Northwick Park Hospital and then on Brain Imaging in the Cyclotron Unit at the Hammersmith Hospital. In 1994 he helped to found the Functional Imaging Laboratory at the Institute of Neurology in Queen Square (subsequently the Wellcome Trust Centre for Neuroimaging at UCL) and was awarded a Wellcome Principal Research Fellowship. From 2007 he has been Emeritus Professor in Neuropsychology at UCL and Niels Bohr Visiting Professor at the University of Aarhus.
Metacognition concerns the processes by which we monitor and control our own cognitive processes. It can also be applied to others, in which case it is known as mentalizing. Both kinds of metacognition have implicit and explicit forms, where implicit means automatic and without awareness. Implicit metacognition enables us to adopt a we-mode, through which we automatically take account of the knowledge and intentions of others. Adoption of this mode enhances joint action. Explicit metacognition enables us to reflect on and justify our behaviour to others. However, access to the underlying processes is very limited for both self and others and our reports on our own and others' intentions can be very inaccurate. On the other hand, recent experiments have shown that, through discussions of our perceptual experiences with others, we can detect sensory signals more accurately, even in the absence of objective feedback. Through our willingness to discuss with others the reasons for our actions and perceptions, we overcome our lack of direct access to the underlying cognitive processes. This creates the potential for us to build more accurate accounts of the world and of ourselves. I suggest, therefore, that explicit metacognition is a uniquely human ability that has evolved through its enhancement of collaborative decision-making.
The remarkable dominance of human beings over other creatures and their ability to control physical forces is a result, in part, of their ability to work together in groups to achieve more than the total work of the individuals involved. In this paper, I will argue that this outstanding feature of human social life depends critically on metacognition. First, therefore, I will briefly outline what I mean by metacognition and make a distinction between the implicit and the explicit forms of metacognition. I will then discuss the role of mentalizing in social interactions, pointing out that this kind of metacognition also has an implicit and an explicit form. Finally, I will show in what way explicit metacognition enables the kinds of group activity that humans are so good at and why explicit metacognition should be considered a uniquely human ability.
2. Metacognition and mentalizing
(a) Metacognition and self-monitoring
The term metacognition refers to the cognitive processes involved in thinking about thinking. Metacognitive processes were first discussed by psychologists interested in strategies for improving learning and memory . These are the processes by which people reflect on their memories (monitoring) and use the knowledge so acquired to regulate these processes (control) . One consequence of monitoring memory might be an experience of the ‘tip-of-the-tongue’ state, in which we feel that we know the answer, even though we are unable to recall it at that moment. A strategy to regulate the retrieval of the word is to deliberately and systematically go through the alphabet testing possible target words beginning with each letter.
More recently, related metacognitive processes of monitoring and control have been studied in signal detection tasks and in reaction time tasks . In the studies of reaction time, the emphasis has been on error detection (monitoring) and on changes in behaviour that occur after an error has been detected (control). For example, after an error, reaction times often increase, reflecting the adoption of a more cautious strategy. However, these studies show that post-error corrections and changes in strategy can occur automatically and quite independently of explicit error detection (for a review see ). This dissociation was observed strikingly in a study of skilled typists in which the experimenters supplied false visual feedback by correcting some of the errors the typists had made and inserting errors that they had not made . The typists slowed down after corrected errors and did not slow down after inserted errors, showing that this outcome of self-monitoring was driven by real errors and was not affected by the false feedback. Nevertheless, many of the typists accepted responsibility for the inserted errors and were unaware of the errors that had been corrected for them.
These results reveal two aspects of metacognition, which are of critical importance to my thesis in this paper. First, there seem to be two forms of self-monitoring. There is an explicit form, which is slow and deliberate, while there is also an implicit form, which is rapid, automatic and can occur without awareness. The question remains open as to whether this implicit form of self-monitoring should even be called metacognition (see  for a discussion of this question). Second, the explicit form of self-monitoring, as we shall see, is highly susceptible to error.