Relations between mental verb and false belief understanding in Cantonese-speaking children

Previous research has shown that linguistic forms that codify mental contents bear a specific relation with children’s false belief understanding. These forms include mental verbs and their following complements, yet the two have not been considered separately. The current study examined the roles of mental verb semantics and the complement syntax in children’s false belief understanding. Independent tasks were used to measure verb meaning, complements, and false belief understanding such that the verbs in question were present only in the verb meaning test, and no linguistic devices biased toward false belief were used in the false belief test. We focused on (a) some mental verbs that obligatorily affirm or negate what follows and (b) sentential complements, the content of which is to be evaluated against the mind of another person, not reality. Results showed that only (a) predicted false belief understanding in a group of Cantonese-speaking 4-year-olds, controlling for nonverbal intelligence and general language ability. In particular, children’s understanding of the strong nonfactive semantics of the Cantonese verbs /ji5-wai4/ (“falsely think”) predicted false belief understanding most strongly. The current findings suggest that false belief understanding is specifically related to the comprehension of mental verbs that entail false thought in their semantics.     

Older children's misunderstanding of uncertain belief after passing the false belief test

A four-location belief task was designed to examine children's understanding of another's uncertain belief after passing a false belief (FB) task. In Experiment 1, after passing the FB task, participants were asked what a puppet would do after he failed to find his toy at the falsely believed location. Most 4-year-olds and half of 6-year-olds children who passed the FB test showed difficulty in handling uncertain belief; answering that the puppet would then look for his toy at the current (moved-to) location. Eight-year-old children and adults all recognized that the puppet would look for the toy everywhere, or at random. In Experiment 2, 4- and 6-year-olds were presented two other search tasks; it was shown that preschoolers could use search strategies to solve a similar search problem when FB was not involved. This new aspect of post-FB understanding can be interpreted in terms of limited understanding of uncertainty in a less-knowledgeable individual and of limited ability to infer the consequences of belief-disconfirmation.     

Language and false belief in Korean-speaking and English-speaking children

The link between language and false belief (FB) understanding has been the focus of considerable debate regarding which language component (semantics, general language, or complementation) is necessary for FB development. We examined the relative roles of complementation and receptive vocabulary in FB development in Korean-speaking and English-speaking children. FB understanding, memory for complements involving the verbs think, say and want, and receptive vocabulary were measured at three time points in 59 Korean-speaking children and 72 English-speaking children. A multi-level growth model indicated that the development of receptive vocabulary and separately the development of think understanding uniquely predicted the development of FB understanding. Neither say nor want was associated with FB understanding. The same pattern was found for Korean- and English-speaking children. The results provide evidence for the role of general language in FB understanding and against the unique role of sentential complementation.     

Sociolinguistic awareness and false belief in young Cantonese learners of English

In this study, we examined whether sociolinguistic awareness and false belief were uniquely related in 3- and 4-year-old Cantonese-speaking children learning English as a second language. The English-use background of these children varied so that they possessed sociolinguistic awareness to different degrees. Results indicated that sociolinguistic awareness predicted false belief uniquely after controlling for age, nonverbal intelligence, English vocabulary, and family income for both the second language learners and the more balanced bilinguals. The group difference in false belief was adequately explained by the corresponding difference in sociolinguistic awareness over and above the other variables. Such findings provide evidence for the claim that false belief understanding is critically related to sociolinguistic awareness, which in turn is influenced by how a second language is learned.     

False belief and language comprehension in Cantonese-speaking children

The current research compared two accounts of the relation between language and false belief in children, namely that (a) language is generally related to false belief because both require secondary representation in a social-interactional context and that (b) specific language structures that explicitly code metarepresentation contribute uniquely to the language-false belief relation. In three studies, attempts were made to correlate Cantonese-speaking children's false belief with their general language comprehension and understanding of certain structures that explicitly express metarepresentational knowledge. Results showed that these structures failed to predict false belief after age, nonverbal intelligence, and general language comprehension were considered. In contrast, general language remained predictive of false belief after controlling for age, nonverbal intelligence, and language structures. The current findings are more consistent with a general language account than a language structure account.     

Counterfactual thinking and false belief: the role of executive function

The purpose of the current study was to examine further the relationship between counterfactual thinking and false belief (FB) as examined by Guajardo and Turley-Ames (Cognitive Development, 19 (2004) 53-80). More specifically, the current research examined the importance of working memory and inhibitory control in understanding the relationship between counterfactual thinking and FB. Participants were 3-, 4-, and 5-year-olds (N = 76). Counterfactual thinking statements generated accounted for significant variance in FB performance beyond age and language. Working memory and inhibitory control each partially mediated the relationship between counterfactual thinking and FB performance. The maturation of executive functioning skills is important in children’s developing understanding of counterfactual reasoning and FB.     

The cost of thinking about false beliefs: evidence from adults' performance on a non-inferential theory of mind task

Much of what we know about other people's beliefs comes non-inferentially from what people tell us. Developmental research suggests that 3-year-olds have difficulty processing such information: they suffer interference from their own knowledge of reality when told about someone's false belief (e.g., [Wellman, H. M., & Bartsch, K. (1988). Young children's reasoning about beliefs. Cognition, 30, 239-277.]). The current studies examined for the first time whether similar interference occurs in adult participants. In two experiments participants read sentences describing the real colour of an object and a man's false belief about the colour of the object, then judged the accuracy of a picture probe depicting either reality or the man's belief. Processing costs for picture probes depicting reality were consistently greater in this false belief condition than in a matched control condition in which the sentences described the real colour of one object and a man's unrelated belief about the colour of another object. A similar pattern was observed for picture probes depicting the man's belief in most cases. Processing costs were not sensitive to the time available for encoding the information presented in the sentences: costs were observed when participants read the sentences at their own pace (Experiment 1) or at a faster or a slower pace (Experiment 2). This suggests that adults' difficulty was not with encoding information about reality and a conflicting false belief, but with holding this information in mind and using it to inform a subsequent judgement.     

Testing the domain-specificity of a theory of mind deficit in brain-injured patients: evidence for consistent performance on non-verbal, "reality-unknown" false belief and false photograph tasks

To test the domain-specificity of "theory of mind" abilities we compared the performance of a case-series of 11 brain-lesioned patients on a recently developed test of false belief reasoning () and on a matched false photograph task, which did not require belief reasoning and which addressed problems with existing false photograph methods. A strikingly similar pattern of performance was shown across the false belief and false photograph tests. Patients who were selectively impaired on false belief tasks were also impaired on false photograph tasks; patients spared on false belief tasks also showed preserved performance with false photographs. In some cases the impairment on false belief and false photograph tasks coincided with good performance on control tasks matched for executive demands. We discuss whether the patients have a domain-specific deficit in reasoning about representations common to both false belief and false photograph tasks.     

Five-year-old children's difficulty with false belief when the sought entity is a person

A total of 153 children (excluding those who erred on control questions), mainly 5 and 7 years of age, participated in two experiments that involved tests of false belief. In the task, the sought entity was first at Location 1 and then, unknown to the searching protagonist, it moved to Location 2. In Experiment 1, performance was well below ceiling in 5-year-olds when the sought entity was a person, and this contrasted with a task in which the sought entity was a physical object. Performance was especially inaccurate when the sought person moved of his or her own volition rather than when the sought person was requested to move by a third party. Interestingly, 5-year-olds were more likely to nominate Location 1 when asked where the searching protagonist would look first than when asked what he or she would do next. In Experiment 2, however, 5-year-olds also tended to nominate Location 1 following a question that included the word "first" even in a test of true belief--a patently incorrect response. Altogether, the results suggest that 5-year-old children have considerable difficulty with a test of false belief when the sought entity is a person acting under his or her own volition. This suggests that 5-year-olds' handle on states of belief is surprisingly fragile in this kind of task.     

33-month-old children succeed in a false belief task with reduced processing demands: A replication of Setoh et al. (2016)

A recent low-inhibition false belief task showed a high success rate with 33-month-old children when response-generation demands were reduced [Setoh, Scott, & Baillargeon (2016). Proceedings of the National Academy of Sciences, 113(47), 13360–13365]. We found correct responding in 74% of N = 58 33-month-old children, replicating the original findings. Within the same sample, we compared this performance with performance in a concurrent measure of false belief understanding which has previously produced competence in children below the age of 3 years [Hughes & Ensor (2007). Developmental Psychology, 43(6), 1447–1459]. Contrasting sharply with findings from the low-inhibition false belief task, we found partial competence in 15%, and full competence in only 5% of the same sample. These results show that the paradigm by Setoh and colleagues generates reliable findings in a different lab and a different language. We discuss this pattern of results in relation to theoretical considerations of early false belief understanding.     

Relationship between implicit false belief understanding and role play: Longitudinal study

Pretend play is one of the earliest forms of children’s imagination. While social pretend play (role play) may facilitate the development of theory of mind – including false belief understanding – theoretically, the reverse may be true; theory of mind may facilitate the development of role play. To clarify this relationship, the present longitudinal study examined whether toddler’s implicit understanding of false beliefs predicted their role play during preschool years. We examined 18-month-old toddlers’ looking time in an implicit false-belief task (Time 1). When the children were 4/5 years old (Time 2), children’s parents answered a questionnaire on their child’s engagement in role play, such as playing with an imaginary companion and impersonating an imagined character. Toddlers’ looking time in the false-belief task at Time 1 predicted impersonation scores at Time 2. The results suggest that early theory of mind skills can facilitate children’s role play.     

Belief-based action prediction in preverbal infants

Successful mindreading entails both the ability to think about what others know or believe, and to use this knowledge to generate predictions about how mental states will influence behavior. While previous studies have demonstrated that young infants are sensitive to others’ mental states, there continues to be much debate concerning how to characterize early theory of mind abilities. In the current study, we asked whether 6-month-old infants appreciate the causal role that beliefs play in action. Specifically, we tested whether infants generate action predictions that are appropriate given an agent’s current belief. We exploited a novel, neural indication of action prediction: motor cortex activation as measured by sensorimotor alpha suppression, to ask whether infants would generate differential predictions depending on an agent’s belief. After first verifying our paradigm and measure with a group of adult participants, we found that when an agent had a false belief that a ball was in the box, motor activity indicated that infants predicted she would reach for the box, but when the agent had a false belief that a ball was not in the box, infants did not predict that she would act. In both cases, infants based their predictions on what the agent, rather than the infant, believed to be the case, suggesting that by 6 months of age, infants can exploit their sensitivity to other minds for action prediction.     

To belief or not belief: Children’s theory of mind

This paper provides a minimalist framework for understanding the development of children’s theory of mind (ToM). First, I provide a critical analysis of rich interpretations of ToM tasks tapping infants’ understanding of perception, goals, intentions, and false beliefs. I argue that the current consensus that infants understand mental states is premature, and instead, that excellent statistical learning skills and attention to human faces and motion enable infants’ very good performance, and reflect an implicit understanding of behavior. Children subsequently develop an explicit understanding of mental states through talk from parents and siblings, their developing language abilities, and their developing distinction between self and other. The paper also examines corollary theories such as the idea that there are subsystems of a theory of mind (ToM), that infants use rules on false belief tasks, that minimalist theory is post hoc, and that parallel onset of success on different ToM tasks indicates an underlying ToM. The paper concludes by considering previous arguments against minimalist interpretations of infant performance.     

Commentary on Ted Ruffman’s “Belief or not belief: …”

I applaud Ruffman for cautioning us against interpreting early sensitivity to others’ beliefs as evidence for an innate theory of mind and for making room for learning. In turn, however, I caution against his claim that all infants need is to understand that people act depending on what they perceive. Instead, infants may keep experiential records (Perner & Roessler, 2010) for other people or records of what they have registered (Apperly & Butterfill, 2009), which makes it less obvious that all required knowledge can be acquired by statistical learning. As a general criticism I remonstrate with current theory of mind research on its lack of concern that we understand people as acting for reasons which goes beyond detecting lawful regularities in behaviour.     

What is “theory of mind”? Concepts,cognitive processes and individual differences

Research on “theory of mind” has traditionally focused on a narrow participant group (preschool children) using a narrow range of experimental tasks (most notably, false-belief tasks). Recent work has greatly expanded the age range of human participants tested to include human infants, older children, and adults, has devised new tasks, and has adopted methods from cognitive psychology and neuroscience. However, theoretical work has not kept pace with these changes, with the result that studies using one kind of method or participant group often inherit assumptions about the nature of theory of mind from other research, with little regard for whether these assumptions are appropriate. I argue that three distinct approaches to thinking about theory of mind are already implicit in research practice, and that future work, whether with infants, children, or adults, will benefit from articulating these approaches more clearly and following their different implications for what theory of mind is and how it should be studied.     

One‐year‐old infants use teleological representations of actions productively

Two experiments investigated whether infants represent goal‐directed actions of others in a way that allows them to draw inferences to unobserved states of affairs (such as unseen goal states or occluded obstacles). We measured looking times to assess violation of infants' expectations upon perceiving either a change in the actions of computer‐animated figures or in the context of such actions. The first experiment tested whether infants would attribute a goal to an action that they had not seen completed. The second experiment tested whether infants would infer from an observed action the presence of an occluded object that functions as an obstacle. The looking time patterns of 12‐month‐olds indicated that they were able to make both types of inferences, while 9‐month‐olds failed in both tasks. These results demonstrate that, by the end of the first year of life, infants use the principle of rational action not only for the interpretation and prediction of goal‐directed actions, but also for making productive inferences about unseen aspects of their context. We discuss the underlying mechanisms that may be involved in the developmental change from 9 to 12 months of age in the ability to infer hypothetical (unseen) states of affairs in teleological action representations.     

Post hoc versus predictive accounts of children’s theory of mind: A reply to Ruffman

Ruffman (2014) argues for a minimalist account of infants’ performance on theory of mind tasks. This commentary argues that because Ruffman’s minimalist account is post hoc, it neither generates testable predictions about how infants will respond in new situations, nor does it offer a coherent explanation for existing false-belief findings. An alternative, mentalist account is presented. This account integrates infancy findings with prior theory of mind literature and generates novel predictions about children’s false belief performance.     

Do people automatically track others’ beliefs? Evidence from a continuous measure

Recent findings suggest that tracking others’ beliefs is not always effortful and slow, but may rely on a fast and implicit system. An untested prediction of the automatic belief tracking account is that own and others’ beliefs should be activated in parallel. We tested this prediction measuring continuous movement trajectories in a task that required deciding between two possible object locations. We independently manipulated whether participants’ belief about the object location was true or false and whether an onlooker’s belief about the object location was true or false. Manipulating whether or not the agent’s belief was ever task relevant allowed us to compare performance in an explicit and implicit version of the same task. Movement parameters revealed an influence of the onlooker’s irrelevant belief in the implicit version of the task. This provides evidence for parallel activation of own and others’ beliefs.     

Children's understanding of teaching: the role of knowledge and belief

The relation between preschoolers’ concept of teaching and theory of mind was explored to determine if there is a developmental change in understanding how teaching depends on knowledge and belief. The study tested whether 3- to 6-year-olds thought the awareness of a knowledge difference is necessary for teaching. The 3- and 4-year-olds understood teaching stories with clear knowledge differences and could correctly use that information to specify the teacher and learner. The 5- and 6-year-olds, who performed well on a standard false belief task, further understood that it was the teacher's belief about the knowledge difference that would actually govern teaching. The conceptual link to teaching suggests that theory of mind is critical for understanding other forms of knowledge acquisition besides perceptual access.     

‘Theory of mind’ development of Pakistani children: Do preschoolers acquire an understanding of desire,pretence and belief in a universal sequence?

Research on “theory of mind” (TOM) suggests that a grasp of the mind develops universally and sequentially, but both these claims require testing in different cultural groups. Study 1, involving 72 preschoolers, showed the expected developmental transition on false belief tasks; 3 year olds were below statistical chance, while 4 year olds were at chance, representing a lag behind Western children. The same pattern of at chance (pretence, desire and belief) and below chance performance (false belief) was replicated in study 2 with 77 preschoolers (3–5 years) and corroborated the lag identified for some Asian countries. This deficient and varied timing of TOM performance is consistent with theories (social constructivist) supporting the role of social factors in TOM development. Moreover, significant inter-task correlations corroborate the need to broaden the research focus beyond false belief tasks.