Beyond belief: knowledge and ignorance processing in adults

This project will investigate the cognitive processing underlying our ability to understand who is knowledgeable, and who is ignorant. This ability is crucial for social interactions, as it enables us to predict and interpret others’ actions, communicate effectively, and, more generally, facilitates the accumulation and transmission of our culture through learning from each other. By adapting behavioural tasks we have recently used to investigate how we process other peoples’ beliefs, we will investigate both explicit and implicit knowledge processing in adults. Philosophers have noted that there is a distinction between knowledge and simply having a belief: while knowing something implies that you believe it, believing something does not mean that you know it. Yet, despite this distinction, the vast majority of psychological research into how we understand others’ mental states (theory of mind) has focused on beliefs rather than knowledge. Although comparative and developmental psychologists have recently taken an interest in knowledge processing (e.g., Martin & Santos, 2016; Harris et al., 2017), contemporary cognitive psychology has very little to say regarding the nature of knowledge and ignorance processing in human adults (Bricker, 2020). Consequently, psychologists and philosophers have recently highlighted the need for new research in order to test current, and develop new, theories of this fundamental feature of theory of mind (Phillips et al., 2021). One theory claims that, unlike belief processing, knowledge and ignorance processing is automatic, requiring little, or no, deliberate conscious thought and therefore likely available to human infants and non-human primates (Phillips et al., 2021; Nagel, 2017). A second theory claims that while knowledge processing might be automatic, ignorance processing very likely requires more deliberate, conscious thought beyond the abilities of non-human primates and possibly human infants (Martin & Santos, 2016). On both theories, however, knowledge processing is the basic foundation from which we build our understanding of others’ mental states. If correct, this view has important implications across the variety of disciplines investigating theory of mind, including developmental and comparative psychology, clinical and behavioural neuroscience, cognitive science, and philosophy. While developmental and comparative psychology offer tentative support to this view, we lack the evidence needed from cognitive psychology to convincingly test these theories. Therefore, across five experiments with adult participants, we will test these theories with the following questions: Is knowledge attribution automatic and more basic than belief attribution? Is ignorance attribution automatic and more basic than false belief attribution? Do we implicitly track others’ knowledge, rather than their beliefs? Our experiments adapt behavioural theory-of-mind tasks that we have previously used to investigate belief attribution, including investigating whether belief attribution is automatic (Apperly, et al., 2006; O’Connor et al., 2023). We will use two types of task: explicit tasks where participants answer questions about another’s knowledge, and implicit tasks where participants do not answer such questions, but we measure knowledge processing nonetheless. By testing these recent theoretical claims, this project will generate new insights into knowledge and ignorance processing in adults, addressing a significant gap in our understanding of this fundamental theory of mind ability. In the long term, a more comprehensive understanding of how we process different mental states may enhance our understanding of the challenges faced by many populations in social interactions, such as those with acquired brain injury or autism (Ferguson & Bradford, 2021).