The knowledge ("true belief") error in 4- to 6-year-old children: When are agents aware of what they have in view?

Detecting lies through others' eyes: Children use perceptual access cues to evaluate listeners' beliefs about informants' deception

Children are often third-party observers of conversations between informants and receivers. Although 5- and 6-year-olds can identify and reject informants' false testimony, it remains unclear whether they expect others to do the same. Accurately assessing others' impressions of informants and their testimony in a conversational setting is essential for children's navigation of the social world. Using a novel second-order lie detection task, the current study examined whether 4- to 7-year-olds (N = 74; Mage = 69 months) take receivers' epistemic states into account when predicting whether a receiver would think an informant is truthful or deceptive. We pitted children's firsthand observations of reality against informants' false testimony while manipulating receivers' perceptual access to a sticker-hiding event. Results showed that when the receiver had perceptual access and was knowledgeable, children predicted that the receiver would think the informant is lying. Critically, when the receiver lacked perceptual access and was ignorant, children were significantly more likely to predict that the receiver would think the informant is telling the truth. Second-order theory of mind and executive function strengthened this effect. Findings are interpreted using a dual-process framework and provide new insights into children's understanding of others' selective trust and susceptibility to deception.

Development of representational theory of mind: Concepts of mental states, awareness of thinking, and self-permanence

In a recent monograph, my students, colleagues, and I reported on a comprehensive set of tests of the theory of Perceptual Access Reasoning (PAR), a new theory of the development of representational theory of mind (ToM). The central tenet of the theory is that young children acquire a hitherto undetected non-representational ToM (i.e., PAR), the use of which allows them to pass standard false belief tasks without understanding false beliefs. Thus, PAR theory capitalizes on an unrecognized flaw in all standard false belief tasks. In what follows, I present an overview of PAR theory, the tests that we have conducted of the theory, and logical arguments for how PAR explains the classic findings in the ToM literature. Next, I evaluate two recent alternate accounts that have been offered by critics, and I discuss some of the issues raised by three invited commentaries on the monograph. Finally, I consider the question, "What is the development of representational ToM the development of?" Insights from philosophy of mind point to the primacy of children's understanding of mental states in themselves, leading to a new concept of self-permanence that can provide the basis for a unified theory of the development of children's understanding of the mental and physical worlds. As a final thought, I consider how PAR was able to hide in plain sight for so long.

Dissociating visual perspective taking and belief reasoning using a novel integrated paradigm: A preregistered online study

There is considerable conceptual overlap between Level-2 Visual Perspective Taking (VPT-2) and Belief Reasoning; both cognitive processes require us to represent another's viewpoint and experience of reality while inhibiting our own egocentric representations. This study investigated if these facets of mentalising are distinct from one another in the general adult population. To do so, we developed a novel "Seeing-Believing Task" with which to compare VPT-2 and true belief (TB) reasoning directly - one in which both judgement types refer to the same state of reality, requiring identical responses, and where self and other perspectives can be dissociated. Across three preregistered online experiments, this task demonstrated consistent differences between these two cognitive processes; specifically, TB judgements were associated with slower response times than VPT-2. This suggests that VPT-2 and TB reasoning are at least partly distinct psychological processes. Further, the greater cognitive effort required for TB reasoning is unlikely to be explained by differences in mnemonic processing. We suggest, therefore, that VPT-2 and TB reasoning differ in the complexity of social processing involved and we discuss theoretical implications based on minimal vs. full-blown Theory of Mind. Future research must attempt to test these conjectures.