Cognitive Architecture of Belief Reasoning in Children and Adults: A Two-Systems Account Primer

Characterizing the cognitive architecture of human mindreading forces us to address two puzzles in people’s attributions of belief: why children show inconsistent expectations about others’ belief-based actions, and why adults’ belief reasoning is sometimes automatic and sometimes not. The seemingly puzzling data suggest humans have multiple mindreading systems that use different models of the mental. The efficient system is shared by infants, children and adults, and uses a minimal model of mind, which enables belief-like states to be tracked. The flexible system is late-developing and uses a canonical model, which incorporates propositional attitudes. A given model’s operation has signature limits that produce performance contrasts, in children as well as adults, between certain types of mindreading tasks. Systems, Models & Signature Limits 2 Our everyday mindreading ability helps us reason about how beliefs might influence people’s actions, inter-personal communications and conduct. There are difficult puzzles surrounding the nature of human beings’ belief attribution: (I) children show an apparently contradictory pattern of success and failure in their responses to scenarios involving others’ belief-based actions, and (II) belief reasoning is both nonautomatic and automatic. To solve these puzzles, we highlight evidence from cognitive studies of children and adults to survey an exciting approach to the architecture of mindreading suggesting that human beings can be in (at least) two minds about the ways in which others’ beliefs cause and rationalize behavior (1, 2). We discuss how ‘signature limits’ on low-level processes make it possible to differentiate between efficient versus flexible instances of mindreading. We then evaluate a contrasting account suggesting that human beings have a unitary and abstract psychological reasoning system from early in life. PUZZLES IN PEOPLE’S ATTRIBUTION OF BELIEF Puzzle I: Infants pass false-belief tasks but 3-year-olds fail? A measure of the development of our mindreading ability is the false-belief task. Wimmer and Perner (3) showed preschoolers a story where Maxi witnesses a target placed at location-X. In Maxi’s absence, the target is moved to location-Y. Children are asked to predict where Maxi would look for the target. Most 3-year-olds answered Maxi would look in Y, as if false-belief were impossible; by contrast, many 4-yearolds answered X, indicating they recognized Maxi’s false-belief. The incorporation of belief into children’s understanding of minds from about age 4-years onwards is a well-replicated and robust experimental finding (4). Once children master verbal Systems, Models & Signature Limits 3 false-belief tasks, they do so systematically and coherently for a large variety of topics and task formats. Importantly, 4-year-olds’ grasp of beliefs includes appreciating that beliefs are essentially aspectual; that is beliefs represent a given object under some guises but not others. Rakoczy, Bergfeld, Schwarz, and Fizke (5) found that when 4year-olds pass standard false-belief tasks, they begin to understand that an agent, depending on how he or she represents something, can mistakenly believe that there are two objects present when, in fact, there is only one. The findings from explicit verbal tasks contrast with results from non-verbal measures. Whereas 3-year-olds’ verbal predictions indicate that they reason as if false-belief were impossible, their gaze anticipations to the same situation indicate that they can track others’ false-beliefs (6, 7, 8). The dissociation is supported by violation-of-expectation studies contrasting looking-times to scenarios that are either consistent or inconsistent with an agent’s belief. Onishi and Baillargeon (9) showed 15-month-olds scenarios of an agent forming either a trueor false-belief about an object’s location. The agent searched in the belief-compatible or the beliefincompatible location. Infants looked longer when the agent searched in the beliefincompatible location. Longer looking is interpreted as infants expecting agents to act according to their beliefs. Other studies suggest that 7to 18-month-olds can track false-beliefs about contents and types of objects, and tailor their helping and communication to others’ false-belief about object-location (10). The first puzzle is thus: How can infants and toddlers display sensitivity to others’ false-beliefs when responding in some ways while they treat false-belief as impossible when responding to the very same situation in other ways? Systems, Models & Signature Limits 4 Puzzle II: Belief reasoning is both non-automatic and automatic Studies of adult humans also point to seemingly incompatible sets of findings regarding the automaticity of mindreading inferences. A mindreading process is automatic if its occurrence is to a significant degree independent of its relevance to participants’ tasks and motives. Apperly and colleagues (11) found that false-beliefs are not ascribed automatically: adults with no specific motivation to attend to a character’s beliefs were slower to respond to unpredictable probe questions about an agent’s false-belief of an object’s whereabouts than to matched control probes. The case for non-automaticity is also supported by research showing that belief tracking frequently depends on attention and working memory resources in fully competent adults and, further, that even merely holding in mind someone else’s belief incurs significant processing costs (12). However, there is also a body of evidence pointing to a different conclusion. Schneider, Nott, and Dux (13) found that a character’s false-belief can influence adults’ visual attention irrespective of the relevance of the belief to the tasks adults were assigned. Both adults who were told to track a character’s belief and adults who were told to track a ball’s location fixated longer at an empty box before the character returned to the scene and falsely believed the box to contain the ball than when the character believed it was empty. Mirroring findings from young children, Van der Wel and colleagues (14) found that the effects of indirect belief calculation were different from the effects of direct belief judgments. Adults saw a ball and a cube disappear behind two screens. A bystander had a false-belief whilst participants had a true-belief about the objects’ locations. Participants who were instructed to move a computer mouse to reach the ball’s location showed involuntary tracking of belief: Systems, Models & Signature Limits 5 their mouse movements to the ball were skewed towards where the bystander falselybelieved the ball to be. Deliberate inferences showed different effects: participants who were told to track beliefs took longer to move the mouse when their beliefs differed from the bystander’s (and their mouse movements were not skewed by the bystander’s beliefs). The second puzzle is thus: How can belief tracking be sometimes but not always automatic?