In a series of three visual perspective-taking experiments, we asked adult participants to judge their own or someone else's visual perspective in situations where both perspectives were either the same or different. We found that participants could not easily ignore what someone else saw when making self-perspective judgments. This was observed even when participants were only required to take their own perspective within the same block of trials (Experiment 2) or even within the entire experiment (Experiment 3), i.e. under conditions which gave participants a clear opportunity to adopt a strategy of ignoring the other person's irrelevant perspective. Under some circumstances, participants were also more efficient at judging the other person's perspective than at judging their own perspective. Collectively, these results suggest that adults make use of rapid and efficient processes to compute what other people can see.

The lack of consensus on how to characterize humans' capacity for belief reasoning has been brought into sharp focus by recent research. Children fail critical tests of belief reasoning before 3 to 4 years of age (H. Wellman, D. Cross, & J. Watson, 2001; H. Wimmer & J. Perner, 1983), yet infants apparently pass false-belief tasks at 13 or 15 months (K. H. Onishi & R. Baillargeon, 2005; L. Surian, S. Caldi, & D. Sperber, 2007). Nonhuman animals also fail critical tests of belief reasoning but can show very complex social behavior (e.g., J. Call & M. Tomasello, 2005). Fluent social interaction in adult humans implies efficient processing of beliefs, yet direct tests suggest that belief reasoning is cognitively demanding, even for adults (e.g., I. A. Apperly, D. Samson, & G. W. Humphreys, 2009). The authors interpret these findings by drawing an analogy with the domain of number cognition, where similarly contrasting results have been observed. They propose that the success of infants and nonhuman animals on some belief reasoning tasks may be best explained by a cognitively efficient but inflexible capacity for tracking belief-like states. In humans, this capacity persists in parallel with a later-developing, more flexible but more cognitively demanding theory-of-mind abilities.

The development of theory of mind use was investigated by giving a computerised task to 177 female participants divided into five age groups: Child I (7.3-9.7 years); Child II (9.8-11.4); Adolescent I (11.5-13.9); Adolescent II (14.0-17.7); Adults (19.1-27.5). Participants viewed a set of shelves containing objects, which they were instructed to move by a "Director" who could see some but not all of the objects. Correct interpretation of critical instructions required participants to use the director's perspective and only move objects that the director could see. In a control condition, participants were asked to ignore objects in slots with a grey background. Accuracy improved similarly in both conditions between Child I and Adolescent II. However, while performance of the Adolescent II and Adult groups did not differ in the control condition, the Adolescent II group made more errors than the adults in the experimental condition. These results suggest that theory of mind use improves between late adolescence and adulthood.Thus, while theory of mind tasks are passed by age four, these data indicate that the interaction between theory of mind and executive functions continues to develop in late adolescence.ToM development during adolescence 3

A standard view in the neuroscience literature is that the frontal lobes sustain our ability to process others' mental states such as beliefs, intentions and desires (this ability is often referred to as having 'theory of mind'). Here we report evidence from brain-damaged patients showing that, in addition to involvement of the frontal lobes, the left temporoparietal junction is necessary for reasoning about the beliefs of others.

What could someone represent that would enable her to track, at least within limits, others' perceptions, knowledge states and beliefs including false beliefs? An obvious possibility is that she might represent these very attitudes as such. It is sometimes tacitly or explicitly assumed that this is the only possible answer. However, we argue that several recent discoveries in developmental, cognitive, and comparative psychology indicate the need for other, less obvious possibilities. Our aim is to meet this need by describing the construction of a minimal theory of mind. Minimal theory of mind is rich enough to explain systematic success on tasks held to be acid tests for theory of mind cognition including many false belief tasks. Yet minimal theory of mind does not require representing propositional attitudes, or any other kind of representation, as such. Minimal theory of mind may be what enables those with limited cognitive resources or little conceptual sophistication, such as infants, chimpanzees, scrub-jays and human adults under load, to track others' perceptions, knowledge states and beliefs.