Are Causal Structure and Intervention Judgments Inextricably Linked? A Developmental Study

The application of the formal framework of causal Bayesian Networks to children’s causal learning provides the motivation to examine the link between judgments about the causal structure of a system, and the ability to make inferences about interventions on components of the system. Three experiments examined whether children are able to make correct inferences about interventions on different causal structures. The first two experiments examined whether children’s causal structure and intervention judgments were consistent with one another. In Experiment 1, children aged between 4 and 8 years made causal structure judgments on a three‐component causal system followed by counterfactual intervention judgments. In Experiment 2, children’s causal structure judgments were followed by intervention judgments phrased as future hypotheticals. In Experiment 3, we explicitly told children what the correct causal structure was and asked them to make intervention judgments. The results of the three experiments suggest that the representations that support causal structure judgments do not easily support simple judgments about interventions in children. We discuss our findings in light of strong interventionist claims that the two types of judgments should be closely linked.     

A reappraisal of the relation between performances of quantitative identity and quantitative equivalence conservation tasks

Previous studies of children's performance on quantitative identity and equivalence conservation problems in the number domain are suggested to be flawed because of the low numbers of items in the arrays. In Experiment 1, children were tested on three different number versions of identity and equivalence conservation tasks. Their performance varied with the number of items and no child was found to pass a large number version of an equivalence conservation task and fail the corresponding version of an identity conservation task. In Experiment 2 the notion that the contextual effect of asking two similar questions might underlie the difference in performance on the two tasks was tested and rejected. The results are discussed in relation to recent analyses of conservation problems.     

Developmental versus sensory deficit effects on perceptual processing in the reading disabled

Thirty children and 5 adults participated in two experiments designed to compare visual processing in normal and reading disabled children. The children were aged 8, 10, and 12 years. In Experiment 1, subjects were asked to detect the temporal order of two briefly presented stimuli. In Experiment 2, subjects sorted cards containing bracket stimuli that did or did not produce perceptual grouping effects. Poor readers required more time to make accurate temporal order judgments and showed stronger perceptual grouping effects. For both good and poor readers, the amount of time necessary to make a correct temporal order judgment decreased, and perceptual grouping effects became weaker with age. However, the magnitude of the difference between the groups did not lessen with age. These results suggest that there are visual processing differences between good and poor readers that do not appear to correct by age 12.     

Facilitation in the abstract selection task: The effects of attentional and instructional factors

The present study examined performance on Wason's four-card abstract selection task. Baseline performance is very poor, usually less than 10% correct; and this task has a long record of resistance to facilitation. It was hypothesized that the two primary sources of difficulty are selective encoding of the problem information and the lack of satisfactory analytic processing. Three experiments were conducted to test this hypothesis. In Experiment 1, performance was improved by explicating the implication rule. The majority of subjects, however, still failed to make the correct selection. Subjects were required in Experiment 2 to provide reasons for their selection or non-selection of each of the cards. This response procedure, paired with an explicated rule, led to further improvements in performance (over 50% correct selections). In Experiment 3, the influence of the type of selection instruction (true-false vs. violation) was examined. Paired with an explicated rule and the reasons response format, violation instructions led to one of the highest correct selection rates ever observed for any version of the selection task: over 80% correct. Because of the importance of this result, it was replicated twice. The results of these three experiments are discussed in terms of Johnson-Laird and Byrne's mental models theory and Evans's two-stage model of reasoning.     

Knowing when you don't know enough: Children's judgements about ambiguous information

Two experiments were carried out to find out whether young children's failure to realise when messages are ambiguous is specific to verbally transmitted information about a person's intended meaning. In Experiment 1, children judged whether they had been told/shown enough to identify which one of a set of cards the experimenter had chosen. In one game the experimenter gave verbal messages about her chosen cards, and in a second game, she gave visual messages. With ambiguous visual messages, relevant parts of cards were physically covered. We expected that this would make it more obvious that the speaker's intended meaning was not being fully conveyed. No difference was found between verbal and visual conditions: correct judgements about message ambiguity occured with the same frequency in both.In Experiment 2, children judged in one game whether they had been told enough about the experimenter's chosen card, as in Experiment 1. In a second game, visual information about a card was not conveyed by the experimenter, Rather, the child operated a pointer, set in a disc with windows, beneath which lay cards. The child judged whether the window showed enough for him/her to tell which card the pointer indicated. Again, correct judgments about ambiguity occured with the same frequency in both games.The results implied that children's failure to realise when verbal messages are ambiguous is but one aspect of a more general failure to realise when one has insufficient information at one's disposal to guarantee a correct interpretation of what the world is like.     

Expertise and gambling: Using Type 2 signal detection theory to investigate differences between regular gamblers and nongamblers

This paper presents an experimental investigation into how individuals make decisions under uncertainty when faced with different payout structures in the context of gambling. Type 2 signal detection theory was utilized to compare sensitivity to bias manipulations between regular nonproblem gamblers and nongamblers in a novel probability-based gambling task. The results indicated that both regular gamblers and nongamblers responded to the changes of rewards for correct responses (Experiment 1) and penalties for errors (Experiment 2) in setting their gambling criteria, but that regular gamblers were more sensitive to these manipulations of bias. Regular gamblers also set gambling criteria that were more optimal. The results are discussed in terms of an expertise-transference hypothesis.     

Word recognition in child second language learners: Evidence from cognates and false friends

We studied how Dutch children learned English as a second language (L2) in the classroom. Learners at different levels of L2 proficiency recognized words under different task conditions. Beginning learners in primary school (fifth and sixth grades) and more advanced learners in secondary school (seventh and ninth grades) made lexical decisions on words that are similar for English and Dutch in both meaning and form (“cognates”) or only in form (“false friends”). Cognates were processed faster than matched control words by all participant groups in an English lexical decision task (Experiment 1) but not in a Dutch lexical decision task (Experiment 2). An English lexical decision task that mixed cognates and false friends (Experiment 3) led to consistently longer reaction times for both item types relative to controls. Thus, children in the early stages of learning an L2 already activate word candidates in both of their languages (language-nonselective access) and respond differently to cognates in the presence or absence of false friends in the stimulus list.     

Establishing discriminative stimulus control within generalized oddity performance,without reinforcement

In two oddity learning studies with children, subjects were reinforced for oddity (or nonoddity) responding on line-tilt or dot numerosity problems. Interposed form and color problems were not reinforced. No instructions to make oddity choices were given. In Experiment I it was found that reinforcement for oddity or nonoddity responding on tilt and numerosity problems produced the corresponding tendency toward oddity or nonoddity performance on these problems and also on the nonreinforced form and color problems. These results show a generalized oddity phenomenon similar to generalized imitation. In Experiment II a third type of nonreinforced problem was presented in this same format: compound stimuli permitting either a color or a form solution. It was found that immediate prior training with nonreinforced form problems, interpolated among the reinforced tilt and numerosity problems, led to form-oddity choices in the compound problems. Similarily, color pretraining produced color-oddity choices. These results show that selective discriminative stimulus control can be obtained in oddity learning, without reinforcement for choices on either of the two dimensions involved.     

Improving conditional discrimination learning and memory in five-year-old children: Differential outcomes effect using different types of reinforcement

Previous studies have demonstrated that discriminative learning is facilitated when a particular outcome is associated with each relation to be learned. When this training procedure is applied (the differential outcomes procedure; DOP), learning is faster and better than when the typical common outcomes procedure or nondifferential outcomes (NDO) is used. Our primary purpose in the two experiments reported here was to assess the potential advantage of DOP in 5-year-old children using three different strategies of reinforcement in which (a) children received a reinforcer following a correct choice (“ + ”), (b) children lost a reinforcer following an incorrect choice (“ ? ”), or (c) children received a reinforcer following a correct choice and lost one following an incorrect choice (“ + / ? ”). In Experiment 1, we evaluated the effects of the presence of DOP and different types of reinforcement on learning and memory of a symbolic delayed matching-to-sample task using secondary and primary reinforcers. Experiment 2 was similar to the previous one except that only primary reinforcers were used. The results from these experiments indicated that, in general, children learned the task faster and showed higher performance and persistence of learning whenever differential outcomes were arranged independent of whether it was differential gain, loss, or combinations. A novel finding was that they performed the task better when they lost a reinforcer following an incorrect choice (type of training “ ? ”) in both experiments. A further novel finding was that the advantage of the DOP over the nondifferential outcomes training increased in a retention test.     

The depiction of imaginary transformations: Early comprehension of a symbolic function

Children were tested for their ability to imagine a pretend transformation and select a representation of its outcome. In Experiment 1, children aged 2 years and above were successful in choosing the correct representation of the imagined transformation, whether represented by a picture or toy. Children below 2 years were unsuccessful on both types of representation. In Experiment 2, children below 2 years, unlike children above 2 years, were unsuccessful in selecting a representation of an actual as well as a pretend transformation. Implications for children's understanding of pretense and iconic symbolism are discussed.     

Memory for lateral orientation of slides in picture stories

Three picture stories were constructed by taking slides of people involved in three different activities. Two sequences of these slides were presented. Subjects were asked whether or not each slide in the second sequence was in the same lateral orientation as in the first sequence. Experiment 1 presented the slides in correct or random sequence and in correct or random lateral orientation (2 by 2 design). The two groups who received correct orientation excelled in recognition of orientation in the test series. Experiment 2 replicated the random orientation condition, found that pre-warning of the recognition task had no effect on performance, and suggested that these subjects did not make use of the events in determining laterality. Experiment 3 replicated the correct order and orientation condition and further revealed that new but appropriate slides in the test series were accurately judged as to lateral orientation which fit the context of the original stories.     

Selection of strategies for narrowing choice options: Antecedents and consequences

This study investigates the antecedents (task and decision maker characteristics) and consequences (set size and decision quality) of prescreening strategy selection. In Experiment 1 we investigated which strategy, inclusion or exclusion, is more natural for narrowing choices in tasks with a single correct answer; about 70% of the participants selected exclusion. Experiment 2 directly contrasted correct answer tasks with personal judgment tasks, using the same foils for the two tasks. Participants were more likely to use exclusion for items with a correct answer than for personal judgments. In Experiment 3, participants could choose different strategies for different items and rated the difficulty of each item. The greater the perceived difficulty of an item, the more likely participants were to choose an exclusion strategy. In all three experiments exclusion led to larger set sizes, across task type and experimental design. There were no differences in decision quality as a function of strategy selection after correcting for set size. Individual differences based on personality inventories were not found to be good predictors of strategy selection, but had moderate effects on set size for personal judgment tasks. Results are discussed in terms of a status quo bias for adding or deleting options from an initial reference frame.     

Hierarchical categorization by bilingual Latino children: does a basic-level bias exist?

Research has shown that children classify most easily at the basic level where objects in the same category look similar enough to each other to be grouped together but are distinct enough from objects in other categories to be discriminated (e.g., animal/bird/duck). In this article, the authors report on 2 experiments they conducted to determine whether children maintain this basic category bias when the perceptual similarity of stimuli at different hierarchical levels is equalized. Pictures within and across 3 hierarchical levels were made perceptually equivalent and shown to 71 Latino children who were bilingual in Spanish and English. In Experiment 1, the pictures used as exemplars could be categorized on any of the 3 hierarchical levels. In Experiment 2, example pictures unambiguously defined the level of categorization that would be accurate, and linguistic cues were given that might assist in the selection of the correct category. In both experiments, the children sorted pictures from all 3 levels equally well, but they found it harder to justify their sorting of superordinate pictures. English competence predicted sorting on the more ambiguous sorting task in Experiment 1; and English competence predicted verbal justifications in both experiments, even though the experiments were conducted in Spanish. Competence in Spanish or English was an equally good predictor of sorting in the better defined sorting task in Experiment 2. These findings indicate that a superordinate level deficiency remains after perceptual differences are eliminated and that the deficiency is cognitive in nature. Differences in the performances of children who differed in bilingualism support the hypothesis that a threshold of proficiency in both languages is an important determinant of the effect of bilingualism on categorization.     

Young children's (Homo sapiens) understanding of knowledge formation in themselves and others.

Three- and 4-year-old children (Homo sapiens) were tested for comprehension of knowledge formation. In Experiment 1, 34 subjects watched as a surprise was hidden under 1 of 4 obscured cups. The experimenter then pointed to the cup. All children searched under the correct cup, but no 3-year-olds (in contrast to most 4-year-olds) could explain how they knew where to look. Subjects then discriminated between simultaneous pointing by 2 adults, one who had hidden a surprise and one who had left the room before the surprise was hidden. Most 4-year-olds (but no 3-year-olds) showed clear discrimination between the adults. In Experiment 2, 16 subjects were tested with procedures designed to make the source of their own knowledge more obvious, but this had no effect on performance. We conclude that studies using very similar procedures with chimpanzees and rhesus macaques were measuring an ability (or inability) to understand how knowledge states form.     

The development of ordinal numerical competence in young children

Two experiments assessed ordinal numerical knowledge in 2- and 3-year-old children and investigated the relationship between ordinal and verbal numerical knowledge. Children were trained on a 1 vs 2 comparison and then tested with novel numerosities. Stimuli consisted of two trays, each containing a different number of boxes. In Experiment 1, box size was held constant. In Experiment 2, box size was varied such that cumulative surface area was unrelated to number. Results show children as young as 2 years of age make purely numerical discriminations and represent ordinal relations between numerosities as large as 6. Children who lacked any verbal numerical knowledge could not make ordinal judgments. However, once children possessed minimal verbal numerical competence, further knowledge was entirely unrelated to ordinal competence. Number may become a salient dimension as children begin to learn to count. An analog magnitude representation of number may underlie success on the ordinal task.     

Conditional probability versus spatial contiguity in causal learning: Preschoolers use new contingency evidence to overcome prior spatial assumptions

This study examines preschoolers' causal assumptions about spatial contiguity and how these assumptions interact with new evidence in the form of conditional probabilities. Preschoolers saw a toy that activated in the presence of certain objects. Children were shown evidence for the toy's activation rule in the form of patterns of probability: The toy was more likely to activate either when objects made contact with its surface (on condition) or when objects were several inches above its surface (over condition). In Experiment 1, 61 three-year-olds saw a deterministic activation rule. In Experiments 2 and 3, 48 four-year-olds saw an activation rule that was probabilistic. In Experiment 4, 30 four-year-olds saw a screening-off pattern of activation. In all 4 experiments, children used new evidence in the form of patterns of probability to make accurate causal inferences, even in the face of conflicting prior beliefs about spatial contiguity. However, children were more likely to make correct inferences when causes were spatially contiguous, particularly when faced with ambiguous evidence.     

The role of common motor responses in stimulus categorization by preschool children

The purpose of this study was to assess the role of common motor responses as the "speaker" behavior on stimulus class formation, and the emergence of functional classes. Experiment 1 examined whether training one motor response to a set of three stimuli and a second motor response to another set of three stimuli would result in correct category-sort responses for 5 typically developing preschool children. Three of the children passed the categorization tests. Experiment 2 examined whether the classes formed in Experiment 1 were functional classes, and whether participants who did not pass categorization tests in Experiment 1 would do so following common vocal tact training. The 2 participants who failed categorization tests in Experiment 1 passed these tests in Experiment 2, although none of the participants passed the tests for functional classes. The results of the current study did not unequivocally support the naming hypothesis. Future research should therefore evaluate other possible sources of control that aid in stimulus categorization.     

The effects of realism on Wason's THOG problem

Summary In this series of experiments the effects of phrasing Wason's THOG problem in realistic terms were investigated. Experiments 1 and 2 used realistic materials of very different kinds, but neither version of the problem produced any facilitation compared with the original abstract version. Experiment 3 used a version of the problem in which the correct answer was cued in by the realistic material, and a significant improvement was found. Experiment 4 used a version of the problem similar to that used in Experiment 3 and again improved performance was found; since the subjects in this experiment were eight- and nine-year-old children, the facilitation almost certainly was not the result of improved logical ability. The results of Experiment 5, however, suggested that it was difficult to cue in adults to give the logically incorrect answer. It is concluded that realism improves performance on this problem only when the realistic material cues in the correct answer from memory. A review of the research that makes use of other reasoning paradigms suggests that this conclusion may hold true for these as well.     

观点采择因素对3～4岁儿童延迟满足决策的影响

通过采用延迟满足决策任务,要求儿童分别为自己和他人做出决策,本研究考察了观点采择因素对儿童情感决策发展的影响。实验一选取3岁和4岁儿童各40名,结果发现3岁儿童和4岁儿童在为自己选和为他人选两种条件下的表现均无显著差异,都倾向于做出延迟选择。实验二选取3岁和4岁儿童各60名,在为他人的选择中进一步区分了不同的观点提示条件,并增加了观点采择测验任务。结果发现,4岁儿童的观点采择能力得到了初步的发展,在不同的观点提示条件下为他人选择时分别表现出了与为自己选择不同的决策趋势;3岁儿童尚未获得观点采择能力,在各种不同观点提示条件下为自己和为他人做选择时差异均不显著。本研究结果表明,观点采择能力对儿童情感决策的影响是发展性的。随着观点采择能力的发展,儿童逐渐能够确立正确的延迟动机,为他人做出有效的决策。     

Expertise and gambling: using type 2 signal detection theory to investigate differences between regular gamblers and nongamblers

This paper presents an experimental investigation into how individuals make decisions under uncertainty when faced with different payout structures in the context of gambling. Type 2 signal detection theory was utilized to compare sensitivity to bias manipulations between regular nonproblem gamblers and nongamblers in a novel probability-based gambling task. The results indicated that both regular gamblers and nongamblers responded to the changes of rewards for correct responses (Experiment 1) and penalties for errors (Experiment 2) in setting their gambling criteria, but that regular gamblers were more sensitive to these manipulations of bias. Regular gamblers also set gambling criteria that were more optimal. The results are discussed in terms of an expertise-transference hypothesis.