False-belief understanding in 2.5-year-olds: evidence from two novel verbal spontaneous-response tasks

Recent research indicates that toddlers and infants succeed at various non-verbal spontaneous-response false-belief tasks; here we asked whether toddlers would also succeed at verbal spontaneous-response false-belief tasks that imposed significant linguistic demands. We tested 2.5-year-olds using two novel tasks: a preferential-looking task in which children listened to a false-belief story while looking at a picture book (with matching and non-matching pictures), and a violation-of-expectation task in which children watched an adult 'Subject' answer (correctly or incorrectly) a standard false-belief question. Positive results were obtained with both tasks, despite their linguistic demands. These results (1) support the distinction between spontaneous- and elicited-response tasks by showing that toddlers succeed at verbal false-belief tasks that do not require them to answer direct questions about agents' false beliefs, (2) reinforce claims of robust continuity in early false-belief understanding as assessed by spontaneous-response tasks, and (3) provide researchers with new experimental tasks for exploring early false-belief understanding in neurotypical and autistic populations.     

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.     

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.     

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.     

Attributing false beliefs about non-obvious properties at 18 months

Reports that infants in the second year of life can attribute false beliefs to others have all used a search paradigm in which an agent with a false belief about an object’s location searches for the object. The present research asked whether 18-month-olds would still demonstrate false-belief understanding when tested with a novel non-search paradigm. An experimenter shook an object, demonstrating that it rattled, and then asked an agent, “Can you do it?” In response to this prompt, the agent selected one of two test objects. Infants realized that the agent could be led through inference (Experiment 1) or memory (Experiment 2) to hold a false belief about which of the two test objects rattled. These results suggest that 18-month-olds can attribute false beliefs about non-obvious properties to others, and can do so in a non-search paradigm. These and additional results (Experiment 3) help address several alternative interpretations of false-belief findings with infants.     

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.     

Attributing false beliefs about non-obvious properties at 18 months

Reports that infants in the second year of life can attribute false beliefs to others have all used a search paradigm in which an agent with a false belief about an object’s location searches for the object. The present research asked whether 18-month-olds would still demonstrate false-belief understanding when tested with a novel non-search paradigm. An experimenter shook an object, demonstrating that it rattled, and then asked an agent, “Can you do it?” In response to this prompt, the agent selected one of two test objects. Infants realized that the agent could be led through inference (Experiment 1) or memory (Experiment 2) to hold a false belief about which of the two test objects rattled. These results suggest that 18-month-olds can attribute false beliefs about non-obvious properties to others, and can do so in a non-search paradigm. These and additional results (Experiment 3) help address several alternative interpretations of false-belief findings with infants.     

Perspective tracking in progress: Do not disturb

Two experiments tested the hypothesis that indirect false-belief tests allow participants to track a protagonist’s perspective uninterruptedly, whereas direct false-belief tests disrupt the process of perspective tracking in various ways. For this purpose, adults’ performance was compared on indirect and direct false-belief tests by means of continuous eye-tracking. Experiment 1 confirmed that the false-belief question used in direct tests disrupts perspective tracking relative to what is observed in an indirect test. Experiment 2 confirmed that perspective tracking is a continuous process that can be easily disrupted in adults by a subtle visual manipulation in both indirect and direct tests. These results call for a closer analysis of the demands of the false-belief tasks that have been used in developmental research.     

Seven-month-old infants chunk items in memory

Although working memory has a highly constrained capacity limit of three or four items, both adults and toddlers can increase the total amount of stored information by "chunking" object representations in memory. To examine the developmental origins of chunking, we used a violation-of-expectation procedure to ask whether 7-month-old infants, whose working memory capacity is still maturing, also can chunk items in memory. In Experiment 1, we found that in the absence of chunking cues, infants failed to remember three identical hidden objects. In Experiments 2 and 3, we found that infants successfully remembered three hidden objects when provided with overlapping spatial and featural chunking cues. In Experiment 4, we found that infants did not chunk when provided with either spatial or featural chunking cues alone. Finally, in Experiment 5, we found that infants also failed to chunk when spatial and featural cues specified different chunks (i.e., were pitted against each other). Taken together, these results suggest that chunking is available before working memory capacity has matured but still may undergo important development over the first year of life.     

Young infants' reasoning about hidden objects: evidence from violation-of-expectation tasks with test trials only

The present research examined alternative accounts of prior violation-of-expectation (VOE) reports that young infants can represent and reason about hidden objects. According to these accounts, young infants' apparent success in these VOE tasks reflects only novelty and familiarity preferences induced by the habituation or familiarization trials in the tasks. In two experiments, 4-month-old infants were tested in VOE tasks with test trials only. The infants still gave evidence that they could represent and reason about hidden objects: they were surprised, as indicated by greater attention, when a wide object became fully hidden behind a narrow occluder (Experiment 1) or inside a narrow container (Experiment 2). These and control results demonstrate that young infants can succeed at VOE tasks involving hidden objects even when given no habituation or familiarization trials. The present research thus provides additional support for the conclusion that young infants possess expectations about hidden objects. Methodological issues concerning the use of habituation or familiarization trials in VOE tasks are also discussed.     

Young Children's Knowledge of the Representational Function of Pictorial Symbols: Development Across the Preschool Years in Three Cultures

Three- to 5-year-old children's knowledge that pictures have a representational function for others was investigated using a pictorial false-belief task. In Study 1, children passed the task at around 4 years old, and performance was correlated with standard false-belief and pictorial symbol tasks. In Study 2, the performance of children from two cultural settings who had very little exposure to pictures during the first 3 years (Peru, India) was contrasted with that of children from Canada. Performance was better in the Canadian than Peruvian and Indian samples on the picture false-belief task and drawing tasks but not on the standard false-belief measure. In all settings, children passed drawing and standard false-belief tasks either concurrently with, or prior to, passing the picture false-belief task. The findings suggest that children's explicit knowledge of the representational function of pictorial symbols matures in the late preschool years and develops more rapidly in cultures that strongly promote the symbolic use of pictures early in life.     

Conflicting desire and the child's theory of mind

We contrast the standard representational theory-of-mind approach to the understanding of mental states with an alternative view that theory-of-mind tasks require executive functioning or the inhibition of more “cognitively salient” information. Two experiments test the hypothesis that 3-year-olds' apparent problems on theory-of-mind tasks are not due to an inability to represent the mental contents of another, but rather lie in the informational structure of the task. In Experiment 1, 3- to 5-year-olds were tested on their understanding of desire in others either when they themselves held a strong and conflicting desire or when they had no strong desire. Results showed that under the condition of having a strong and conflicting desire, only 5-year-olds were able to recognize that another person may desire something different. In contrast, when the children themselves held no strong desire, even 3-year-olds were able to judge another's desire correctly. Experiment 2 compared 3-year-olds' performance on a standard false-belief task with an equivalently structured desire task in which participants had again to inhibit their own strong and conflicting desire. Results showed similar performance on the traditional false-belief task and the new conflicting-desire task.     

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.     

Children's understanding of promising, lying, and false belief

Understanding promising and lying requires an understanding of intention and the ability to interpret mental states. The author examined (a) the extent to which 4- to 6-year-olds focus on the sincerity of the speaker's intention when the 4-to 6-year-olds make judgments about promises and lies and (b) whether false-belief reasoning skills are related to understanding promising and lying. Participants watched videotaped stories and made promise and lie judgments from their own perspective and from the listener-character's perspective. Children also completed false-belief reasoning tasks. Older children made more correct promise judgments from both perspectives. All children made correct lie judgments from the listener's perspective. The author found that Ist-order false-belief reasoning was related to making judgments from the participant's perspective; 2nd-order false-belief reasoning was related to making judgments from the listener-character's perspective. Results suggest that children's understanding of promising and lying moves from a focus on outcome toward a focus on the belief that each utterance is designed to create.     

婴儿是否拥有错误信念理解能力?

最近10多年,越来越多的婴儿错误信念理解研究不断拓展自发反应任务的范围,发现婴儿的任务表现具有一定的灵活性。对此,有研究者坚持丰富解释,认为婴儿能理解他人的错误信念;也有研究者坚持贫瘠解释,认为婴儿只是借助行为规则等通过任务;近来还有研究者在新的概念框架下做出一种折衷的解释。最终解决婴儿是否拥有错误信念理解能力这个问题,需要研究者们提出一个判定个体拥有错误信念理解能力的明确标准。     

Toddlers' use of cues in a search task

Search for a ball that has undergone hidden motion rapidly improves during the second year of life (Dev. Psychol., 2000; 36 :394–401). In three experiments we investigated whether the poor performance of younger toddlers was due to attentional failure by highlighting the major cue for the hidden object. We observed only slight improvement in search behaviour. We performed two other experiments that tested the depth of understanding of 3‐year‐olds in this task and found that their performance was robust to changes in the apparatus and experimental procedures. Overall, the results point to a rapidly developing ability in the second year of life to either reason about space or select the correct motor response in search tasks. Copyright © 2008 John Wiley & Sons, Ltd.     

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.     

Concurrent Relations Between Perspective-Taking Skills,Desire Understanding,and Internal-State Vocabulary

Recent studies suggest that there appears to be a similar developmental sequence in the understanding of mental states in both internal-state language and in standard theory-of-mind tasks. These findings suggest possible developmental relations between children's ability to talk and think about the mind. Two experiments investigated the concurrent relations between internal-state vocabulary and theory-of-mind abilities in 30-month-old toddlers. In Experiment 1, children's internal-state language vocabulary was significantly and specifically related to their concurrent understanding of others' visual and emotional perspectives and was less strongly related to desire understanding. Experiment 2 replicated and extended these findings by examining the link between internal-state vocabulary and visual perspective-taking and comprehension of own versus other's desire, controlling for general verbal skills. Children with a more developed internal-state vocabulary performed better on perspective-taking tasks. These findings suggest that labeling and reasoning about mental states are related abilities at the early stages of theory-of-mind development.     

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。     

儿童二级错误信念认知与二级情绪理解的发展

以来自两所幼儿园的133名儿童为被试,探讨了3~6岁儿童二级错误信念认知和二级情绪理解的发展分化与联系。结果发现,6岁左右是儿童的二级错误信念认知和二级情绪理解发展的关键期;4岁左右的儿童能够掌握二级未知知识,获得情绪解码能力;儿童的二级未知与二级错误信念认知之间,儿童的情绪解码与二级情绪理解之间,在发展上存在1~2年的差距;二级推理能力是儿童进行二级心理状态认知的关键。