Knowing the limits of one's understanding: the development of an awareness of an illusion of explanatory depth

Adults overestimate the detail and depth of their explanatory knowledge, but through providing explanations they recognize their initial illusion of understanding. By contrast, they are much more accurate in making self-assessments for other kinds of knowledge, such as for procedures, narratives, and facts. Two studies examined this illusion of explanatory depth with 48 children each in grades K, 2, and 4, and also explored adults' ratings of the children's explanations. Children judged their understanding of mechanical devices (Study 1) and procedures (Study 2). Second and fourth graders showed a clear illusion of explanatory depth for devices, recognizing the inaccuracy of their initial impressions after providing explanations. The illusion did not occur for knowledge of procedures.     

Meaning matters in children's plural productions

The English plural is about the number of individuals in a set of like kinds. Two-year-old children use the plural but do not do so in all obligatory contexts. The present report asks whether the limitations on their production of the plural are related to aspects of meaning. In two Experiments plural productions were elicited from 2-year-old children for sets of size two and four and for instances of basic-level categories that were either similar or identical. Children were much more likely to produce the plural of these well-known nouns when there were four rather than two and when the instances were identical rather than merely similar. The results provide new evidence on children's acquisition of the English plural, showing that children's early productions are not just limited by knowledge of the noun and its plural form but also is limited by properties of the labeled sets in ways that are relevant to the underlying meaning of the plural.     

Developmental differences in children's context-dependent word learning

In this study, 2.5-, 3-, and 4-year-olds (N = 108) participated in a novel noun generalization task in which background context was manipulated. During the learning phase of each trial, children were presented with exemplars in one or multiple background contexts. At the test, children were asked to generalize to a novel exemplar in either the same or a different context. The 2.5-year-olds’ performance was supported by matching contexts; otherwise, children in this age group demonstrated context dependent generalization. The 3-year-olds’ performance was also supported by matching contexts; however, children in this age group were aided by training in multiple contexts as well. Finally, the 4-year-olds demonstrated high performance in all conditions. The results are discussed in terms of the relationship between word learning and memory processes; both general memory development and memory developments specific to word learning (e.g., retention of linguistic labels) are likely to support word learning and generalization.     

Lexical competition in young children's word learning

In two experiments, 1.5-year-olds were taught novel words whose sound patterns were phonologically similar to familiar words (novel neighbors) or were not (novel nonneighbors). Learning was tested using a picture-fixation task. In both experiments, children learned the novel nonneighbors but not the novel neighbors. In addition, exposure to the novel neighbors impaired recognition performance on familiar neighbors. Finally, children did not spontaneously use phonological differences to infer that a novel word referred to a novel object. Thus, lexical competition--inhibitory interaction among words in speech comprehension--can prevent children from using their full phonological sensitivity in judging words as novel. These results suggest that word learning in young children, as in adults, relies not only on the discrimination and identification of phonetic categories, but also on evaluating the likelihood that an utterance conveys a new word.     

Young children's reasoning about the order of past events

Four studies are reported that employed an object location task to assess temporal-causal reasoning. In Experiments 1-3, successfully locating the object required a retrospective consideration of the order in which two events had occurred. In Experiment 1, 5- but not 4-year-olds were successful; 4-year-olds also failed to perform at above-chance levels in modified versions of the task in Experiments 2 and 3. However, in Experiment 4, 3-year-olds were successful when they were able to see the object being placed first in one location and then in the other, rather than having to consider retrospectively the sequence in which two events had happened. The results suggest that reasoning about the causal significance of the temporal order of events may not be fully developed before 5 years.     

The consistency of false suggestions moderates children's reports of a single instance of a repeated event: predicting increases and decreases in suggestibility

Participants (6- and 7-year-olds, N=130) participated in classroom activities four times. Children were interviewed about the final occurrence (target event) either 1 week or 4 weeks later, during which half of the event items were described inaccurately. Half of these suggestions were consistent with the theme of the detail across the occurrences (e.g., always sat on a kind of floor mat) or were inconsistent (e.g., sat on a chair). When memory for the target event was tested 1 day later, children falsely recognized fewer inconsistent suggestions than consistent suggestions, especially compared with a control group of children who experienced the event just one time. Furthermore, the longer delay reduced accuracy only for consistent suggestions. Source-monitoring ability was strongly and positively related to resistance to suggestions, and encouraging children to identify the source of false suggestions allowed them to retract a significant proportion of their reports of inconsistent suggestions but not of consistent suggestions. The results suggest that the gist consistency of suggestions determines whether event repetition increases or decreases suggestibility.     

Children's working understanding of knowledge sources: Confidence in knowledge gained from testimony

In three experiments, children aged between 3 and 5 years (N = 38, 52, 94; mean ages 3–7 to 5–2) indicated their confidence in their knowledge of the identity of a hidden toy. With the exception of some 3-year-olds, children revealed working understanding of their knowledge source by showing high confidence when they had seen or felt the toy, and lower confidence when they had been told its identity by an apparently well-informed speaker. Correct explicit source reports were not necessary for children to show relative uncertainty when the speaker subsequently doubted the adequacy of his access to the toy. After a 2-min delay, 3–4-year-olds, unlike 4–5-year-olds, failed to see the implications of the speaker's doubt about his access.     

Children's sensitivity to circular explanations

The ability to evaluate the quality of explanations is an essential part of children's intellectual growth. Explanations can be faulty in structural ways such as when they are circular. A circular explanation reiterates the question as if it were an explanation rather than providing any new information. Two experiments (N=77) examined children's preferences when faced with circular and noncircular explanations. The results demonstrate that a preference for noncircular explanations is present, albeit in a fragile form, by 5 or 6 years of age and that it appears robustly by 10 years of age. Thus, the ability to evaluate the quality of explanations based on structural grounds appears to develop rapidly during the elementary school years.     

Time keeping and working memory development in early adolescence: A 4-year follow-up

In this longitudinal study, we examined time keeping in relation to working memory (WM) development. School-aged children completed two tasks of WM updating and a time monitoring task in which they indicated the passing of time every 5 min while watching a film. Children completed these tasks first when they were 8 to 12 years old and then 4 years later when they were 12 to 16 years old. Time keeping in early adolescence showed a different pattern of outcome measures than 4 years earlier, with reduced clock checking and increased timing error. However, relative changes in WM development moderated these adverse effects. Adolescents with greater relative gains in WM development were better calibrated than participants with less developing WM functions. We discuss these findings in relation to individual and developmental differences in executive control functions and socioemotionally driven reward seeking.     

How focus at encoding affects children’s source monitoring

Retention of source information is enhanced by focus on speakers’ feelings about statements even though recognition is reduced for both adults and children. However, does any focus on another person lead to enhanced source monitoring, or is a particular kind of focus required? Does other-focus enhance source monitoring, or does self-focus detract from it? In Experiment 1, 4- and 6-year-olds watched two speakers make statements in a no-focus control or with focus directed on how they (or a speaker) felt about the statements or on perceptual features about themselves (or the speaker). Source monitoring decisions were enhanced by other-focus in both the perceptual and emotional conditions. However, the effect was larger for the emotional condition, and source monitoring exceeded no-focus controls only for this condition. Experiment 2 showed no effect of other-focus versus self-focus on source monitoring when questions were semantic.     

An associative account of the development of word learning

Word learning is a notoriously difficult induction problem because meaning is underdetermined by positive examples. How do children solve this problem? Some have argued that word learning is achieved by means of inference: young word learners rely on a number of assumptions that reduce the overall hypothesis space by favoring some meanings over others. However, these approaches have difficulty explaining how words are learned from conversations or text, without pointing or explicit instruction. In this research, we propose an associative mechanism that can account for such learning. In a series of experiments, 4-year-olds and adults were presented with sets of words that included a single nonsense word (e.g. dax). Some lists were taxonomic (i.,e., all items were members of a given category), some were associative (i.e., all items were associates of a given category, but not members), and some were mixed. Participants were asked to indicate whether the nonsense word was an animal or an artifact. Adults exhibited evidence of learning when lists consisted of either associatively or taxonomically related items. In contrast, children exhibited evidence of word learning only when lists consisted of associatively related items. These results present challenges to several extant models of word learning, and a new model based on the distinction between syntagmatic and paradigmatic associations is proposed.     

Young children's selective learning of rule games from reliable and unreliable models

We investigated preschoolers’ selective learning from models that had previously appeared to be reliable or unreliable. Replicating previous research, children from 4 years selectively learned novel words from reliable over unreliable speakers. Extending previous research, children also selectively learned other kinds of acts – novel games – from reliable actors. More important, – and novel to this study, this selective learning was not just based on a preference for one model or one kind of act, but had a normative dimension to it. Children understood the way a reliable actor demonstrated an act not only as the better one, but as the normatively appropriate or correct one, as indicated in both their explicit verbal comments and their spontaneous normative interventions (e.g., protest, critique) in response to third-party acts deviating from the one demonstrated. These findings are discussed in the broader context of the development of children's social cognition and cultural learning.     

Working memory and children's use of retrieval to solve addition problems

This study tested the hypothesis that children with high working memory capacities solve single-digit additions by direct retrieval of the answers from long-term memory more often than do children with low working memory capacities. Counting and reading letter span tasks were administered to groups of third-grade (mean age=107 months) and fourth-grade (mean age=118 months) children who were also asked to solve 40 single-digit additions. High working memory capacity was associated with more frequent use of retrieval and faster responses in solving additions. The effect of span on the use of retrieval increased with the size of the minimum addend. The relation between working memory measures and use and speed of retrieval did not depend on the numerical or verbal nature of the working memory task. Implications for developmental theories of cognitive arithmetic and theories of working memory are discussed.     

Attribution of movement: Potential links between subjective reports of agency and output monitoring

According to agency memory theory, individuals decide whether “I did it” based on a memory trace of “I am doing it”. The purpose of this study was to validate the agency memory theory. To this end, several hand actions were individually presented as samples, and participants were asked to perform the sample action, observe the performance of that action by another person, or imagine performing the action. Online feedback received by the participants during the action was manipulated among the different conditions, and output monitoring, in which participants were asked whether they had performed each hand action, was conducted. The rate at which respondents thought that they themselves had performed the action was higher when visual feedback was unaltered than when it was altered (Experiment 1A), and this tendency was observed across all types of altered feedback (Experiment 1B). The observation of an action performed by the hand of another person did not increase the rate at which respondents thought that they themselves had performed the action unless the participants actually did perform the action (Experiments 2A and 2B). In Experiment 3, a relationship was observed between the subjective feeling that “I am the one who is causing an action” and the memory that “I did perform the action”. These experiments support the hypothesis that qualitative information and sense of “self” are tagged in a memory trace and that such tags can be used as cues for judgements when the memory is related to the “self”.     

Remote control and children's understanding of robots

Children use goal-directed motion to classify agents as living things from early in infancy. In the current study, we asked whether preschoolers are flexible in their application of this criterion by introducing them to robots that engaged in goal-directed motion. In one case the robot appeared to move fully autonomously, and in the other case it was controlled by a remote. We found that 4- and 5-year-olds attributed fewer living thing properties to the robot after seeing it controlled by a remote, suggesting that they are flexible in their application of the goal-directed motion criterion in the face of conflicting evidence of living thing status. Children can flexibly incorporate internal causes for an agent’s behavior to enrich their understanding of novel agents.     

"It's magic!" The effects of presentation modality on children's event memory, suggestibility, and confidence judgments

The current study investigated the influence of presentation modality (live, video, and slide show) on children's memory, suggestibility, recognition, and metamemorial monitoring processes. A total of 270 children in three age groups (5- and 6-year-olds, 7- and 8-year-olds, and 9- and 10-year-olds) watched a magic show and were questioned about it 1 week later. The live show yielded more correct answers to nonleading questions, higher resistance to misleading questions, and better recognition memory than did the video condition, which in turn resulted in better performance than did the slide show. Although presentation modality raised the general level of memory performance, the effects were equally strong in all age groups and did not affect memory phenomena such as the size of the misinformation effect and confidence judgments.     

The effect of cues on young children's abilities to discriminate among thoughts, feelings and behaviours

OBJECTIVE: To determine if cues help young children discriminate among thoughts, feelings and behaviours. PARTICIPANTS: Ninety-six children aged 4-7 years from three schools in Norwich, UK. DESIGN: Within each age band (4, 5, 6, 7), children were randomised to the cue or the no cue condition on a stratified basis ensuring that equal numbers of boys and girls from each school were in each of the eight cells (cue condition x age). Cues were glove puppets and post boxes. The effect of IQ was controlled. MEASURES: A discrimination task, in which children were asked to identify a thought, a feeling and a behaviour from each of six brief stories, and a brief IQ assessment were administered to children individually. RESULTS: There was a significant effect of age and cue condition on performance; older children and those who were presented with the cue performed better. There were no gender differences and no interaction between cue condition and age. CONCLUSION: Many young children discriminated among thoughts, feelings and behaviours suggesting that they may be able to engage in this aspect of cognitive behaviour therapy. Simple cues (puppets and posting boxes) improved children's performance and these may be useful therapeutic tools with young children.     

False rumors and true belief: Memory processes underlying children’s errant reports of rumored events

Previous research has shown that overhearing an errant rumor—either from an adult or from peers—about an earlier experience can lead children to make detailed false reports. This study investigates the extent to which such accounts are driven by changes in children’s memory representations or merely social demands that encourage the reporting of rumored information. This was accomplished by (a) using a warning manipulation that eliminated social pressures to report an earlier heard rumor and (b) examining the qualitative characteristics of children’s false narratives of a rumored-but-nonexperienced event. Findings indicated that overheard rumors can induce sensory and contextual characteristics in memory that can lead children to develop genuine false beliefs in seeing rumored-but-nonexperienced occurrences. Such constructive tendencies were especially likely among 3- and 4-year-olds (relative to 5- and 6-year-olds) and when rumors were picked up from peers during natural social interactions (relative to when they were planted by an adult).     

Children's understanding of death as the cessation of agency: a test using sleep versus death

An important problem faced by children is discriminating between entities capable of goal-directed action, i.e. intentional agents, and non-agents. In the case of discriminating between living and dead animals, including humans, this problem is particularly difficult, because of the large number of perceptual cues that living and dead animals share. However, there are potential costs of failing to discriminate between living and dead animals, including unnecessary vigilance and lost opportunities from failing to realize that an animal, such as an animal killed for food, is dead. This might have led to the evolution of mechanisms specifically for distinguishing between living and dead animals in terms of their ability to act. Here we test this hypothesis by examining patterns of inferences about sleeping and dead organisms by Shuar and German children between 3 and 5-years old. The results show that by age 4, causal cues to death block agency attributions to animals and people, whereas cues to sleep do not. The developmental trajectory of this pattern of inferences is identical across cultures, consistent with the hypothesis of a living/dead discrimination mechanism as a reliably developing part of core cognitive architecture.