The nature and extent of adults' egocentric bias when reasoning about what others see and believe.

As adult humans we regularly predict and explain others' actions by describing their mental states such as what that person can see, what they believe and what they want: e.g., the girl opened the fridge because she wanted an ice cream and believed there was an ice cream in the fridge. This ability is called a 'theory of mind' because adults generate predictions about others' mental states and behaviours. However, while adults are capable of predicting others' mental states they are prone to errors when making these predictions. This project will test why adults make these errors and whether these errors occur more often depending on the type and nature of the prediction being made.

To investigate the errors made by adults' the project focuses on the errors made by adults when taking into account another's perspective because this ability is also required for reasoning about another's belief. Consequently, errors in perspective taking are particularly informative because they are likely to lead to errors in other forms of mental state attribution. Thus, the project will involve testing adults on a range of perspective taking tasks to investigate the nature and the cognitive processes underlying their errors.

The first objective is to test whether the number of errors made by adults during perspective taking tasks is influenced by the type of perspective taking required. There are two levels of perspective taking and we aim to compare adults' performance between these two levels. A simple form of perspective taking involves taking into account what another person can see (level 1 perspective taking). A more complicated form of perspective taking involves taking into account that how another person sees something can differ to how you see it (for instance, Jill may see a white ball behind a colour filter as if it were a blue ball; level 2 perspective taking). This is important because a comparison between the errors made on each type of perspective taking would indicate whether errors are linked to how complex the perspective taking is.

The second objective is to test whether errors made by adults during perspective taking tasks are limited to visual perspective taking. Previous research has only tested whether adults make errors when reasoning about what other people can see. It is yet unclear whether adults make errors when reasoning about what others hear. Testing whether errors are limited to one sense is crucial in informing us about the nature of these errors. Moreover, our tests will provide highly needed validation of the current assumption that the errors shown by adults when reasoning about visual perspective are informative about perspective taking in general.

The third objective is to test whether the errors made by adults are unique to reasoning about mental states. To address this we will present adults with tasks that do not require attributing a mental state but that reflect specific cognitive requirements of perspective taking tasks. Two components of perspective taking tasks may be leading to adults' errors. Firstly, participants are required to ignore their own perspective. Secondly, participants need to represent what is represented in another person's perspective (meta-representation). Consequently, we aim to test whether adults' errors are due to reasoning about mental states or due to errors in these two cognitive processes which are inherent in mental state attribution tasks but which are not specifically required for mental state attribution.

By testing all three objectives we hope to achieve a comprehensive understanding of adults' errors in perspective taking tasks that will inform us about the nature of these errors. This will have important implications for the academic community interested in theory of mind and may have practical ramifications both for testing whether patients with brain injuries have deficits in theory of mind and for the professions that require perspective taking

The project will have a number of beneficiaries outside of the immediate academic audience. In particular the project will have beneficiaries stemming from the public awareness of this area of science and knowledge of adults' errors when attributing perspectives has the potential to inform and change professional practice in relevant professions.

Public Awareness:
- General Public
The project aims to increase the general public's awareness of this area of experimental psychology. People experience the errors in perspective taking during their everyday lives and this provides a great opportunity to inform them about the reasons for the errors. This is important in fostering peoples interest in the limits of human cognition and in experimental psychology. Through our engagement activities we hope to provide an insight into the methodology of the experiments and the process behind creating experiments.

- Museums/Science Festivals
The project also aims to run a number of live science events where members of the general public take part in shorter, fun, versions of the tasks we are using. This will not only increase the public awareness of the science behind our experiments but will also provide an engaging exhibit in a museum or science festival.

Influencing and informing practitioners and professional practice:

- Clinical Psychology/Psychiatry
The project implements novel ways of testing mental state attribution and the cognitive processes underlying these errors. This presents an opportunity for the development of new tests of mental state attribution that could be used by psychiatrists and clinical psychologists when assessing patients.
Drivers and other professions

-Professional activities involving perspective taking
A number of professional activities involve taking into account the perspectives of others and together with future research this project may influence and inform the practices of these professions. For instance, drivers regularly have to consider whether another road user will be able to notice indications that they are going to make a manoeuvre. This project will help to evaluate the cases where someone is going to mistakenly think that their indications were clear. Future research will have the potential to test how these mistakes could be reduced which could influence professional practice.