The Essential Child. Susan Gelman. New York: Oxford University Press. 2003. 392 pages, $49.95 (US), cloth or paper.

To evaluate the claim that correct performance on unexpected transfer false-belief tasks specifically involves mental-state understanding, two experiments were carried out with children with autism, intellectual disabilities, and typical development. In both experiments, children were given a standard unexpected transfer false-belief task and a mental-state-free, mechanical analogue task in which participants had to predict the destination of a train based on true or false signal information. In both experiments, performance on the mechanical task was found to correlate with that on the false-belief task for all groups of children. Logistic regression showed that performance on the mechanical analogue significantly predicted performance on the false-belief task even after accounting for the effects of verbal mental age. The findings are discussed in relation to possible common mechanisms underlying correct performance on the two tasks.     

3~6岁汉语儿童语言能力与错误信念理解关系的元分析

本研究综合了来自中国大陆1581名3~6岁儿童的语言能力与错误信念关系的19个研究的数据, 通过元分析考查了二者相关的强度, 并分析了影响相关强度的因素, 包括所测量的语言能力及研究使用的错误信念任务的差异等。结果显示当控制了儿童的年龄后, 语言能力和错误信念之间存在中等强度的相关; 研究中所测查的语言能力的类型、使用的错误信念的测量任务的类型不会对语言能力和错误信念的关系强度产生影响。     

Synchrony in the onset of mental-state reasoning: evidence from five cultures

Over the past 20 years, developmental psychologists have shown considerable interest in the onset of a theory of mind, typically marked by children's ability to pass false-belief tasks. In Western cultures, children pass such tasks around the age of 5 years, with variations of the tasks producing small changes in the age at which they are passed. Knowing whether this age of transition is common across diverse cultures is important to understanding what causes this development. Cross-cultural studies have produced mixed findings, possibly because of varying methods used in different cultures. The present study used a single procedure to measure false-belief understanding in five cultures: Canada, India, Peru, Samoa, and Thailand. With a standardized procedure, we found synchrony in the onset of mentalistic reasoning, with children crossing the false-belief milestone at approximately 5 years of age in every culture studied. The meaning of this synchrony for the origins of mental-state understanding is discussed.     

Theory of mind and epistemological development: the relation between children's second-order false-belief understanding and their ability to reason about evidence

The study investigates the hypothesis that children's ability to attribute second-order beliefs facilitates their understanding of evidence, as seen in the ability to distinguish between causes and reasons. Seventy-four children 5–7 yr old were given belief and evidence tests. The belief tests assessed their ability to represent and reason from second-order false-beliefs, and the evidence tests assessed their ability to distinguish between the cause of a situation and a person's reason for believing it. The relation between performance on the two tests was determined, taking into account general language and non-verbal reasoning abilities. Results show that performance on the belief test and on the evidence part of the evidence test improved significantly over the age range, and that a significant proportion of variance in the evidence test scores is accounted for by second-order false-belief understanding, over and above that accounted for by general language and non-verbal abilities. The argument is made that second-order false-belief understanding is fundamental to children's epistemological development, underlying not just their understanding of evidence, but also their understanding of inference and truth.     

Exploring mental-state reasoning as a social-cognitive mechanism for social loafing in children

The authors explored mental-state reasoning ability among 72 preschoolers (ages 3-5 years) as a possible developmental mechanism for the well-known social loafing effect: diminished individual effort in a collaborative task. The authors expected that older children would outperform young children on standard mental-state reasoning tests and that they would display greater social loafing than younger children. In addition, we hypothesized that the ability to infer the mental states of others would be predictive of social loafing, but that the ability to reason about one's own knowledge would not. The authors gave children three standard false-belief tasks and participated in a within-subjects balloon inflation task that they performed both individually and as part of a group. Results indicated that 3-year-olds performed significantly below older preschoolers on mental-state reasoning tasks. Only 4- and 5-year-olds displayed diminished individual effort. Multiple regression analysis indicated that only the ability to reason about others' false beliefs accounted for a significant amount of variance in social loafing; age (in months) and own false-belief reasoning did not. The authors discussed theoretical and pedagogical implications.     

Longitudinal Relations Between 2-Year-Olds' Language and 4-Year-Olds' Theory of Mind

Maternal reports of child vocabulary, utterance length, morpheme usage, and sentence complexity and experimenter-assessed receptive and expressive language were obtained at the end of the 2nd year for European American middle-class toddlers (N = 27). Maternal verbal intelligence and socioeconomic status were also measured. At 48 months of age, children's false-belief understanding and verbal intelligence were evaluated. Individual differences in child language at 24 months and child verbal IQ at 48 months predicted unique variance in performance on the false-belief tasks at 48 months, although only the early language factor findings were statistically significant. These findings demonstrate previously unobserved relations between early language and later acquisition of complex concepts related to mind.     

错误信念任务中的知识偏差

有观点指出,年幼儿童在错误信念任务上的发展变化,不是发生了概念变化的质变,而是知识偏差的表现。知识偏差是指当我们尝试理解一个更不知情的观点时,不能忽略自己拥有的额外信息并受此影响而产生偏差的倾向。本文对知识偏差的含义及其在错误信念任务中可能产生的影响做了较为详细的综述和分析,并就在错误信念任务中消除知识偏差影响的可能性进行了探讨。     

How do use and comprehension of mental-state language relate to theory of mind in middle childhood?

This study investigates the relationship between mental-state language and theory of mind in primary school children. The participants were 110 primary school students (mean age = 9 years and 7 months; SD = 12.7 months). They were evenly divided by gender and belonged to two age groups (8- and 10-year-olds). Linguistic, metacognitive and cognitive measures were used to assess the following competencies: verbal ability, use of mental-state terms, understanding of metacognitive language, understanding of second-order false beliefs, and emotion comprehension. Correlations between children’ use of mental-state language and their performance on theory-of-mind tasks were moderate, whereas correlations between children's comprehension of such language and ToM abilities were high. In addition, regression analyses showed that comprehension of metacognitive language was the variable which best explained children's performance on both false belief tasks and an emotion comprehension test when verbal ability and age were controlled for.     

Low-Income Preschoolers' False-Belief Performance

A group of 72 preschoolers (36 African Americans, 36 European Americans) enrolled in Head Start programs and other preschools serving low-income children were asked 3 variations of false-belief questions across 3 scenarios and given a language and cognition subtest. Children's performance varied across the questions and tasks, but after covarying for children's language and cognitive scores, those effects were no longer found to be significant. Age effects were still significant even after differences in children's language and cognitive abilities had been accounted for. Although no language and cognitive differences were found among European Americans and African Americans, the European Americans still outperformed African Americans on 1 of the task scenarios. Those results demonstrate (a) the importance of considering testing procedures and language and cognitive abilities when assessing children's social cognitive skills and (b) that age-related changes in false-belief understanding are associated with social cognitive conceptual changes that are independent of language and cognitive skills.     

3～5岁幼儿错误信念理解能力的发展趋势

基于以往支持心理理论执行功能表达论的研究结果,对标准错误信念任务修正后采用阶段性错误信念任务,运用实验法对101名3~5岁儿童进行研究。结果发现:(1)新任务保留了标准错误信念任务的优势,能勾勒出幼儿错误信念理解能力的发展趋势;(2)3~5岁儿童表现出不同层次和水平的错误信念理解能力;(3)具体分析儿童错误信念的理解能力发展的心理模式,发现每一年龄组具有的错误信念理解能力,都是其更高水平能力发展的基础,支持表达论。     

Low-income preschoolers' false-belief performance

A group of 72 preschoolers (36 African Americans, 36 European Americans) enrolled in Head Start programs and other preschools serving low-income children were asked 3 variations of false-belief questions across 3 scenarios and given a language and cognition subtest. Children's performance varied across the questions and tasks, but after covarying for children's language and cognitive scores, those effects were no longer found to be significant. Age effects were still significant even after differences in children's language and cognitive abilities had been accounted for. Although no language and cognitive differences were found among European Americans and African Americans, the European Americans still outperformed African Americans on 1 of the task scenarios. Those results demonstrate (a) the importance of considering testing procedures and language and cognitive abilities when assessing children's social cognitive skills and (b) that age-related changes in false-belief understanding are associated with social cognitive conceptual changes that are independent of language and cognitive skills.     

Complements to cognition: a longitudinal study of the relationship between complex syntax and false-belief-understanding

A longitudinal study traced the development of the understanding of false belief and various measures of spontaneous language production and comprehension over the course of one year. The subjects were 28 normally developing preschoolers who averaged 3–5 years when the study began. The children were given a battery of tasks to assess false-belief-understanding and language mastery during four testing periods, with the contents of the materials varying and counterbalanced. The results of regression analyses strongly suggest that the mastery of a specific aspect of syntax, namely tensed complements, is a precursor and possible prerequisite of successful false-belief performance.     

Fonctions exécutives et théorie de l’esprit chez le jeune enfant : une relation réciproque ?

The aim of this study was to assess the specific relation between 18-month-olds’ performance on tasks measuring language skills, executive function (EF) and theory of mind (ToM). The ToM tasks included measures of intention and false-belief understanding whereas working memory and inhibitory control were assessed with three EF tasks. Expressive vocabulary was assessed with the MacArthur Communicative Development Inventory. The main findings showed that both aspects of ToM are strongly linked at this age to inhibitory control, but not to working memory abilities. Language skills were not associated with either ToM or EF abilities. With regard to inter-tasks coherence within EF and ToM, we replicated previous findings with no consistency across EF tasks but an association between false-belief and intention understanding. Overall, these findings provide evidence for a link between executive function and theory of mind at the youngest age ever tested. They also challenge the view that EF is not required to succeed on the false-belief task based on spontaneous responses.     

Matched false-belief performance during verbal and nonverbal interference

Language has been shown to play a key role in the development of a child's theory of mind, but its role in adult belief reasoning remains unclear. One recent study used verbal and nonverbal interference during a false-belief task to show that accurate belief reasoning in adults necessarily requires language (Newton & de Villiers, 2007). The strength of this inference depends on the cognitive processes that are matched between the verbal and nonverbal inference tasks. Here, we matched the two interference tasks in terms of their effects on spatial working memory. We found equal success on false-belief reasoning during both verbal and nonverbal interference, suggesting that language is not specifically necessary for adult theory of mind.     

A longitudinal study of the relation between language and theory-of-mind development.

Fifty-nine 3-year-olds were tested 3 times over a period of 7 months in order to assess the contribution of theory of mind to language development and of language to theory-of-mind development (including the independent contributions of syntax and semantics). Language competence was assessed with a standardized measure of reception and production of syntax and semantics (the Test of Early Language Development). Theory of mind was assessed with false-belief tasks and appearance-reality tasks. Earlier language abilities predicted later theory-of-mind test performance (controlling for earlier theory of mind), but earlier theory of mind did not predict later language test performance (controlling for earlier language). These findings are consistent with the argument that language is fundamental to theory-of-mind development.     

Are Infants’ Theory-of-Mind Abilities Well Integrated? Implicit Understanding of Intentions,Desires, and Beliefs

The development of theory of mind (ToM) in infancy has been mainly documented through studies conducted on a single age group with a single task. Very few studies have examined ToM abilities other than false belief, and very few studies have used a within-subjects design. During 2 testing sessions, infants aged 14 and 18 months old were administered ToM tasks based on the violation-of-expectation paradigm which measured intention, true belief, desire, and false-belief understanding. Infants’ looking times at the congruent and incongruent test trials of each task were compared, and results revealed that both groups of infants looked significantly longer at the incongruent trial on the intention and true-belief tasks. In contrast, only 18-month-olds looked significantly longer at the incongruent trial of the desire task and neither age group looked significantly longer at the incongruent trial on the false-belief task. Additionally, intertask comparisons revealed only a significant relation between performance on the false-belief and intention task. These findings suggest that implicit intention and true-belief understanding emerge earlier than desire and false-belief understanding and that ToM constructs do not appear to be integrated, as is the case for explicit ToM.     

Thinking while talking: adults fail nonverbal false-belief reasoning

This experiment tested the ability of 81 adult subjects to make a decision on a simple nonverbal false-belief reasoning task while concurrently either shadowing prerecorded spoken dialogue or tapping along with a rhythmic shadowing track. Our results showed that the verbal task, but not tapping, significantly disrupted false-belief reasoning, suggesting that language plays a key role in working theory of mind in adults, even when the false-belief reasoning is nonverbal.     

Language input and child syntax

Existing work on the acquisition of syntax has been concerned mainly with the early stages of syntactic development. In the present study we examine later syntactic development in children. Also, existing work has focused on commonalities in the emergence of syntax. Here we explore individual differences among children and their relation to variations in language input. In Study 1 we find substantial individual differences in children's mastery of multiclause sentences and a significant relation between those differences and the proportion of multiclause sentences in parent speech. We also find individual differences in the number of noun phrases in children's utterances and a significant relation between those differences and the number of noun phrases in parent speech. In Study 2 we find greater syntactic growth over a year of preschool in classes where teachers' speech is more syntactically complex. The implications of our findings for the understanding of the sources of syntactic development are discussed.     

Theory of mind and executive function: working-memory capacity and inhibitory control as predictors of false-belief task performance

This study of the relationship between theory of mind and executive function examined whether on the false-belief task age differences between 3 and 5 ears of age are related to development of working-memory capacity and inhibitory processes. 72 children completed tasks measuring false belief, working memory, and inhibition. Significant age effects were observed for false-belief and working-memory performance, as well as for the false-alarm and perseveration measures of inhibition. A simultaneous multiple linear regression specified the contribution of age, inhibition, and working memory to the prediction of false-belief performance. This model was significant, explaining a total of 36% of the variance. To examine the independent contributions of the working-memory and inhibition variables, after controlling for age, two hierarchical multiple linear regressions were conducted. These multiple regression analyses indicate that working memory and inhibition make small, overlapping contributions to false-belief performance after accounting for age, but that working memory, as measured in this study, is a somewhat better predictor of false-belief understanding than is inhibition.     

Children’s first and second-order false-belief reasoning in a verbal and a low-verbal task

We can understand and act upon the beliefs of other people, even when these conflict with our own beliefs. Children’s development of this ability, known as Theory of Mind, typically happens around age 4. Research using a looking-time paradigm, however, established that toddlers at the age of 15 months old pass a non-verbal false-belief task (Onishi and Baillargeon in Science 308:255–258, 2005). This is well before the age at which children pass any of the verbal false-belief tasks. In this study we present a more complex case of false-belief reasoning with older children. We tested second-order reasoning, probing children’s ability to handle the belief of one person about the belief of another person. We find just the opposite: 7-year-olds pass a verbal false-belief reasoning task, but fail on an equally complex low-verbal task. This finding suggests that language supports explicit reasoning about beliefs, perhaps by facilitating the cognitive system to keep track of beliefs attributed by people to other people.