When and why do humans fail to use their "theory of mind"?

Theory of Mind (ToM) is the ability to think about what others see, know, think, want and intend, and is thought to be a fundamental basis of social interaction and communication. ToM has been widely studied in young children and infants, and more recently its cognitive and neural basis has begun to be studied in adults. Of course, adults undoubtedly "have" ToM abilities, but their ability to actually use ToM to guide everyday activities is poorly understood. This is an important question for fundamental psychological research on social cognition and language, where ToM abilities are frequently believed to be critical, and where there is evidence of significant variation in ToM-use both between individuals and between "Western" and "Eastern" cultures. Understanding when and how ToM is used is also important for understanding impairments in ToM following brain injury, or in neurodevelopmental disorders, such as autism. Finally, with increasing "socialisation" of human-computer interfaces, which may use virtual agents who speak and interact with their users, it is increasingly important to know when and how humans succeed and fail in their use of ToM. Only by doing so will it be possible to optimise such systems for their human users. The current project will investigate fundamental questions about ToM-use that will be of interest to these broad audiences.
Reflection on communication with others leads to conflicting intuitions about when and how ToM abilities are used. Viewed one way, communication can feel relatively effortless, suggesting that my consideration of your perspective during our conversation is cognitively efficient and highly accurate. On the other hand, we can probably think of many instances where communication is disrupted because of a failure of perspective-taking. This feeds an intuition that designing what we say in a way that is appropriate for the audience may be rather effortful, and indeed error-prone. This tension is reflected in the scientific literature on ToM-use, where apparently contradictory findings about adults' abilities to take account of a speaker's perspective when interpreting what they say have led to heated debate both about the validity of experimental methods and about how the findings from these studies should be interpreted. The guiding hypothesis for the proposed work is that the polarisation of this debate may be an error: There will be no simple "yes or no" answer about whether adults use their ToM online during communication. Instead we should pay attention to the factors that may influence people's ability to use ToM, and how it is that these influences have their effect. To do this we will use both computer-based laboratory methods that allow relevant factors to be manipulated with very precise control, and we will examine how these findings generalise to "live" interactions between speaker and listener, and the degree to which these same factors might explain development of ToM-use in children and individual differences in ToM-use in adults.
Our main paradigm requires participants to follow instructions from a speaker who does not fully share their visual perspective on the scene under discussion. Critical instructions have different meanings depending on whether or not participants successfully take the speaker's perspective into account. Previous work by the applicants, our collaborator at the University of Chicago, and others, shows that adults frequently show errors when following such instructions, and such difficulty is also observed in more sensitive measures, based on participants' eye movements during the tasks.
By adapting these tasks, our findings will provide insights about 1) the extent and limits of adults' abilities to use their ToM 2) how these limits vary between cultures (Western versus Chinese) 3) how they change through children's development into adults, and 4) whether people who are good at ToM-use have generally better social abilities.

Public understanding of the science of communication and child development.
A primary non-academic impact of our work will be in helping people to understand a fundamental basis of social co-ordination in adults, how these abilities develop in children, and how they might vary across cultures. Exciting research on the ability of infants and very young children to "mindread" has received wide public attention, and provides parents and teachers with a basis for understanding early changes in children's social abilities. However, much less work has examined these abilities in older children or adults. Our work will address this gap in understanding by investigating fundamental aspects of social understanding, how such understanding is put to work during communication, how these abilities change through mid to late childhood, and how they vary between cultures. Our work will help us understand why it is that children and adults, who are clearly capable of understanding that other people have a different point of view from them, nonetheless fail in some circumstances to take these different perspectives into account. Such failures correspond to everyday experience of difficulty with communication, and it is of popular interest to know how and when such difficulties might arise and how they might be overcome.

Audiences of teachers, parents and the public at large will be reached through 1) outreach work that we undertake in collaboration with Birmingham Thinktank (the Birmingham Science Museum - see accompanying letter of support), where we conduct demonstrations and discussion sessions with visitors to the museum, 2) public seminars and discussion sessions at the annual British Science Festival, and 3) "debriefing" activities with schools where we test, which may involve a talk or a letter to staff/parents, explaining our research findings and putting them in broader context. In addition to these activities we will take opportunities to disseminate our findings more widely to the public. For example, the PI (Apperly) has appeared on local BBC radio to discuss research findings on "mindreading", and his work has been highlighted in both New Scientist and Science magazines.

Capacity building
The named researcher, Jessica Wang, already has experience with running computer-based eye-tracking experiments using the Eyelink1000 system. This expertise will be extended to the conduct of "live" (i.e. not computer-based) experiments in which participants interact with another person. This will extend Jessica Wang's training to the Eyelink2 head-mounted system, and will bring the capacity to conduct such "live" studies to the Birmingham group.