How Much Does a Shared Name Make Things Similar? Linguistic Labels, Similarity, and the Development of Inductive Inference

This article examines the development of inductive generalization, and presents a model of young children's induction and two experiments testing the model. The model specifies contribution of linguistic labels and perceptual similarity to young children's induction and predicts a correspondence between similarity judgment and induction of young children. In Experiment 1, 4- to 5-year-olds, 7- to 8-year-olds, and 11- to 12-year-olds were presented with triads of schematic faces (a Target and two Test stimuli), which varied in perceptual similarity, with one of the Test stimuli sharing a linguistic label with the Target, and another having a different label. Participants were taught an unobservable biological property about the Target and asked to generalize the property to one of the Test stimuli. Although 4- to 5-year-olds' proportions of label-based inductive generalizations varied with the degree of perceptual similarity among the compared stimuli, 11- to 12-year-olds relied exclusively on labels, and 7- to 8-year-olds appeared to be a transitional group. In Experiment 2 these findings were replicated using naturalistic stimuli (i.e., photographs of animals), with perceptual similarity manipulated by "morphing" naturalistic pictures into each other in a fixed number of steps. Overall results support predictions of the model and point to a developmental shift from treating linguistic labels as an attribute contributing to similarity to treating them as markers of a common category-a shift that appears to occur between 8 and 11 years of age.     

Attentional learning and flexible induction: how mundane mechanisms give rise to smart behaviors

Young children often exhibit flexible behaviors relying on different kinds of information in different situations. This flexibility has been traditionally attributed to conceptual knowledge. Reported research demonstrates that flexibility can be acquired implicitly and it does not require conceptual knowledge. In Experiment 1, 4- to 5-year-olds successfully learned different context-predictor contingencies and subsequently flexibly relied on different predictors in different contexts. Experiments 2A and 2B indicated that flexible generalization stems from implicit attentional learning rather than from rule discovery, and Experiment 3 pointed to very limited strategic control over generalization behaviors in 4- to 5-year-olds. These findings indicate that mundane mechanisms grounded in associative and attentional learning may give rise to smart flexible behaviors.     

Trait Understanding or Evaluative Reasoning? An Analysis of Children''s Behavioral Predictions

This study tested the hypothesis that in predicting the future behavior of an actor, older children rely on trait inferences, whereas younger children rely on global, evaluative inferences. Vignettes depicting actors engaging in trait-relevant behaviors were presented to 5- and 6-year-olds (N = 67) and 9- and 10-year-olds (N = 71). For each actor, children made predictions of future behavior, evaluated the goodness and badness of the actor, and rated each actor on a relevant trait. A mediational analysis found that the behavioral predictions of older children were mediated solely by trait ratings, whereas those of younger children were mediated by evaluative ratings. Furthermore, unlike older children, younger children made trait-like predictions only when they made an evaluation of the actor. These results suggest that young children utilize evaluative reasoning when making behavioral predictions, and therefore rely on an inferential process that is distinct from that of older children.     

The Use of Trait Labels in Making Psychological Inferences

Three studies investigated children's capacity to use trait labels as tools for making inferences about mental states. For example, knowledge that a story character is "nice" as opposed to "mean" could lead to predictions that the character would respond with greater negative affect upon discovering that his or her action had made someone upset. Study 1 (N = 48) examined whether participants (kindergartners, second graders, fifth graders, and adults) would make different psychological inferences based on whether a character was labeled as "nice" versus "mean." Study 2 (N = 30) examined the same issue with 4-year-olds using a simpler methodology. Study 3 (N = 30) extended the results of Study 2, by examining whether describing characters as "shy" versus "not shy" would lead 4-year-olds to make different mental state inferences. Taken together, these findings suggest that even for young children, trait labels can serve as a basis for making nonobvious inferences. Developmental differences are discussed.     

Children's ability to impute inferentially based knowledge

Do young children appreciate the importance of access to premises when judging what another person knows? In Experiment 1, 5-year-olds (N=31) were sensitive to another person's access to premises when predicting that person's ability to point to a target after eliminating alternatives in a set of 3 cartoon characters. Experiment 2 replicated the finding when 5- to 6-year-olds (N=102) judged who the other person thought the target was, and whether the other person knew who the target was. Experiment 3 demonstrated that children aged 5-7 years (N=107) more successfully imputed inference by elimination than syllogistical inferential knowledge. Findings suggest that an early understanding of inference by elimination offers a route into understanding that people can sometimes gain knowledge without direct perceptual access.     

Epistemic states and traits: preschoolers appreciate the differential informativeness of situation-specific and person-specific cues to knowledge

Previous research has demonstrated that preschoolers can use situation-specific (e.g., visual access) and person-specific (e.g., prior accuracy) cues to infer what others know. The present studies investigated whether 4- and 5-year-olds appreciate the differential informativeness of these types of cues. In Experiment 1 (N = 50), children used others' prior labeling accuracy as a cue when learning labels for, but not the visual identity of, hidden objects. In Experiment 2 (N = 64), with both cues present, children attended more to visual access than prior accuracy when learning the visual identity of, but not labels for, hidden objects. These findings demonstrate that children appreciate the difference between situation- and person-specific cues and flexibly evaluate these cues depending on what information they are seeking.     

Taking decisions seriously: young children's understanding of conventional truth

Research suggests that young children may see a direct and one-way connection between facts about the world and epistemic mental states (e.g., belief). Conventions represent instances of active constructions of the mind that change facts about the world. As such, a mature understanding of convention would seem to present a strong challenge to children's simplified notions of epistemic relations. Three experiments assessed young children's abilities to track behavioral, representational, and truth aspects of conventions. In Experiment 1, 3- and 4-year-old children (N = 30) recognized that conventional stipulations would change people's behaviors. However, participants generally failed to understand how stipulations might affect representations. In Experiment 2, 3-, 5-, and 7-year-old children (N = 53) were asked to reason about the truth values of statements about pretenses and conventions. The two younger groups of children often confused the two types of states, whereas older children consistently judged that conventions, but not pretenses, changed reality. In Experiment 3, the same 3- and 5-year-olds (N = 42) participated in tasks assessing their understanding of representational diversity (e.g., false belief). In general, children's performance on false-belief and "false-convention" tasks did not differ, which suggests that conventions were understood as involving truth claims (as akin to beliefs about physical reality). Children's difficulties with the idea of conventional truth seems consistent with current accounts of developing theories of mind.     

Preschoolers are sensitive to the speaker's knowledge when learning proper names

Unobservable properties that are specific to individuals, such as their proper names, can only be known by people who are familiar with those individuals. Do young children utilize this “familiarity principle” when learning language? Experiment 1 tested whether forty-eight 2- to 4-year-old children were able to determine the referent of a proper name such as “Jessie” based on the knowledge that the speaker was familiar with one individual but unfamiliar with the other. Even 2-year-olds successfully identified Jessie as the individual with whom the speaker was familiar. Experiment 2 examined whether children appreciate this principle at a general level, as do adults, or whether this knowledge may be specific to certain word-learning situations. To test this, forty-eight 3- to 5-year-old children were given the converse of the task in Experiment 1—they were asked to determine the individual with whom the speaker was familiar based on the speaker’s knowledge of an individual’s proper name. Only 5-year-olds reliably succeeded at this task, suggesting that a general understanding of the familiarity principle is a relatively late developmental accomplishment.     

Phantoms and fabrications:young children's detection of implausible lies

The present study investigated whether young children are gullible and readily deceived by another's lies. Specifically, this study examined whether young children believe a lie teller's statement when the statement violates their developing knowledge of a distinction between reality and fantasy. In the first three experiments 3- to 6-year-olds (N = 293) were presented with either a story or a live staged event in which an individual made an implausible statement about a misdeed (claiming that a ghost jumped out of a book and broke a glass). A significant age effect was obtained: 5- and 6-year-olds tended to report that the individual who made the implausible statement had actually committed the misdeed, whereas 3- and 4-year-olds tended to accept the claim of the protagonist. Experiment 4 revealed that 5- and 6-year-olds (N = 43) not only disbelieved an individual's implausible statement but also inferred that the individual was lying and had a deceptive intent. In contrast, Experiment 5 revealed that 3- and 4-year-olds (N = 41) had difficulty disbelieving an individual's implausible claim about an inanimate object (i.e., the claim that a chair came alive and broke the glass). The findings suggest that 5- and 6-year-olds are not so gullible as previously thought, and that they use their well-developed real-world knowledge to detect scapegoating lies. In contrast, many younger children tend to believe another's implausible lies, perhaps due to the fact that the knowledge needed to detect such lies has not yet been consolidated.     

A Similarity Heuristic in Children’s Possibility Judgments

Children often judge that strange and improbable events are impossible, but the mechanisms behind their reasoning remain unclear. This article (N = 250) provides evidence that young children use a similarity heuristic that compares potential events to similar known events to determine whether events are possible. Experiment 1 shows that 5- to 6-year-olds who hear about improbable events go on to judge that similar improbable events can happen. Experiment 2 shows that 5- to 6-year-olds more often affirm that improbable events can happen if told about related improbable events than if told about unrelated ones. Finally, Experiment 3 shows that 5- to 6-year-olds affirm the possibility of improbable events related to known events, but deny that related impossible events can happen.     

Young children's understanding of random phenomena

2 experiments on the development of the understanding of random phenomena are reported. Of interest was whether children understand the characteristic uncertainty in the physical nature of random phenomena as well as the unpredictability of outcomes. Children were asked, for both a random and a determined phenomenon, whether they knew what its next outcome would be and why. In Experiment 1, 4-, 5-, and 7-year-olds correctly differentiated their responses to the question of outcome predictability; the 2 older groups also mentioned appropriate characteristics of the random mechanism in explaining why they did not know what its outcome would be. Although 3-year-olds did not differentiate the random and determined phenomena, neither did they treat both phenomena as predictable. This latter result is inconsistent with Piaget and Inhelder's characterization of an early stage of development. Experiment 2 was designed to control for the possibility that children in Experiment 1 learned how to respond on the basis of pretest experience with the 2 different phenomena. 5- and 7-year-olds performed at a comparable level to the same-aged children in Experiment 1. Results suggest an earlier understanding of random phenomena than previously has been reported and support results in the literature indicating an early understanding of causality.     

When induction meets memory: evidence for gradual transition from similarity-based to category-based induction

The ability to perform induction appears early; however, underlying mechanisms remain unclear. Some argue that early induction is category based, whereas others suggest that early induction is similarity based. Category- and similarity-based induction should result in different memory traces and thus in different memory accuracy. Performing induction resulted in low memory accuracy in adults and 11-year-olds, whereas 5-, and 7-year-olds were highly accurate (Experiment 1). After training to perform category-based induction, 5- and 7-year-olds exhibited patterns of accuracy similar to those of adults (Experiment 2). Furthermore, 7-year-olds, but not 5-year-olds, retained this training over time (Experiment 3). With novel categories, even adults performed similarity-based induction, exhibiting high memory accuracy (Experiment 4). These results suggest a gradual transition from similarity- to category-based induction with familiar categories.     

Overcoming the positive-capture strategy in young children: learning about indeterminacy

Two experiments were conducted to examine whether and how 4- and 5-year-olds learn to distinguish determinate from indeterminate evidence. Children were asked to decide whether various patterns of evidence were sufficient to reach unambiguous conclusions. This study replicated the finding that young children tend to use a strategy that, although generally successful, fails on evidence patterns in which a single positive instance co-occurs with an unexplored source of evidence. Experiment 1 demonstrated that this positive-capture strategy is deeply entrenched, even in a meaningful, pragmatic context. With a microgenetic design, Experiment 2 revealed that young children are capable of replacing the positive-capture strategy with a correct strategy when they are exposed to various analogous tasks in several training sessions.     

Self-Recognition in Young Children Using Delayed versus Live Feedback: Evidence of a Developmental Asynchrony

The ability of young children to recognize themselves in delayed videotapes and recent photographs was investigated using a delayed analog of the mirror mark test, as well as verbal reports. In Experiment 1, 42 2–4-year-old children were videotaped while playing an unusual game. During the game an experimenter covertly placed a large sticker on the child's head. The videotape was played back 3 min later to the children. Older, but not younger, children reached up to remove the sticker when the tape revealed it being placed on their heads. In Experiment 2, a similar procedure was used with 60 3- and 4-year-olds where Polaroid photographs were taken during and after the act of the sticker being placed on the child's head. When allowed to look at the photographs, young 3-year-olds did not reach up to search for the sticker, whereas older 3- and 4-year-olds did. Almost all of the children who did not appear to realize that there was a sticker on their head from the information provided by the photographs did provide a correct verbal label for the image, and reached up to remove the sticker when presented with a mirror. Experiment 3 compared the reaction of 48 21/2–31/2-year-olds to live versus delayed video feedback and indicated an effect of the temporal aspect of the stimulus. The results are discussed in the context of the different forms of self-conception that may underwrite the 2 manifestations of self-recognition.     

Children's Understanding of Knowledge Acquisition: The Tendency for Children to Report That They Have Always Known What They Have Just Learned

Children's attention to knowledge-acquisition events was examined in 4 experiments in which children were taught novel facts and subsequently asked how long they had known the new information. In Experiment 1, 4- and 5-year-olds tended to claim they had known novel animal facts for a long time and also reported that other children would know the novel facts. This finding was replicated in Experiment 2, using facts associated with chemistry demonstrations. In Experiments 3 and 4, children were taught new color words. 5-year-olds, but not 4-year-olds, distinguished between novel and familiar color words, reporting they had not known the novel words before the test session, but they had always known the familiar words. 4-year-olds in Experiment 4 were better able to distinguish novel and familiar color words when the teaching of the novel words was an explicit and salient part of the procedure.     

Early understanding of the division of cognitive labor

Two studies with 3-, 4-, and 5-year-olds (N = 104) examined whether young children can differentiate expertise in the minds of others. Study 1 revealed that all children in the sample could correctly attribute observable knowledge to familiar experts (i.e., a doctor and a car mechanic). Further, 4- and 5-year-olds could correctly attribute knowledge of underlying scientific principles to the appropriate experts. In contrast, Study 2 demonstrated that 3-, 4-, and 5-year-olds have difficulty making attributions of knowledge of scientific principles to unfamiliar experts. A computational analysis in Study 3 indicated that 4- and 5-year-olds' successes on the first two studies could not be attributed to the way in which words co-occur in discourse. Overall, these studies showed that young children have a sense of the division of cognitive labor, albeit fragile.     

The development of forward search planning in preschoolers

Previous evidence suggesting that young children have some ability to plan by means of forward search suffers from typical findings that individual performance is inconsistent and group performance is low. In the present study, evidence is sought that children's imperfect performance results from unstable execution of the correct component processes of forward search, rather than from use of flawed or incomplete rules. 4- and 5-year-olds participated in a route-planning task in which they collected items from several locations in a large space. Incorrect routes required having to backtrack to locations previously visited. Forward search in this task required 3 component processes: representing a possible route, evaluating the route for backtracking, and if necessary, repeating the procedure for an alternate route. Evidence from stochastic parameter estimation and from children's self-corrections and explanations showed that 5-year-olds engaged in forward search, but that 4-year-olds used only a rudimentary form of forward search. Developmental changes involved children's ability to foresee and avoid backtracking, to consider alternate routes, and to spontaneously self-correct errors. Results are discussed in terms of implications for our understanding of the structure and development of early problem-solving skills in general.     

Compositionality and statistics in adjective acquisition: 4-year-olds interpret tall and short based on the size distributions of novel noun referents

Four experiments investigated 4-year-olds' understanding of adjective-noun compositionality and their sensitivity to statistics when interpreting scalar adjectives. In Experiments 1 and 2, children selected tall and short items from 9 novel objects called pimwits (1-9 in. in height) or from this array plus 4 taller or shorter distractor objects of the same kind. Changing the height distributions of the sets shifted children's tall and short judgments. However, when distractors differed in name and surface features from targets, in Experiment 3, judgments did not shift. In Experiment 4, dissimilar distractors did affect judgments when they received the same name as targets. It is concluded that 4-year-olds deploy a compositional semantics that is sensitive to statistics and mediated by linguistic labels.     

Reasoning in Young Children: Fantasy and Information Retrieval

The present article examines 2 predictions concerning conditional reasoning in children derived from Markovits's model of conditional reasoning. The first claims that children under 12 years of age should be able to respond correctly to uncertain logical forms if the premises and context enable them to access pertinent counterexamples from memory. The second concerns the effect of reasoning in a fantasy context. Previous studies have established that young children can correctly respond to certain reasoning problems with empirically false premises when these are presented in a fantasy context. However, this model of reasoning predicts that presenting empirically true premises in a fantasy context should decrease performance on the 2 uncertain logical forms. In Study 1, a total of 48 8-year-olds, 78 10-year-olds, and 74 12-year-olds were given 4 reasoning problems involving familiar premises. These problems were embedded in either a fantasy or a realistic context and presented via video tape. Results were consistent with the predictions made. Study 2 attempted to determine whether these results could be due to context or problem formulation. A total of 40 7-year-olds and 46 8-year-olds were given reasoning problems with either no context or with a visual image preceding the problems. Results showed that children did equally well in these conditions, and that providing an image did not improve performance.