Two- and three-year-olds infer and reason about design intentions in order to categorize broken objects

In naming artifacts, do young children infer and reason about the intended functions of the objects? Participants between the ages of 2 and 4 years were shown two kinds of objects derived from familiar categories. One kind was damaged so as to undermine its usual function. The other kind was also dysfunctional, but made so by adding features that appeared to be intentional. Evidence that 2‐, 3‐ and 4‐year‐olds were more likely to apprehend the broken objects than the intentionally dysfunctional objects as members of the familiar lexical categories favors the conclusion that, in naming, children may spontaneously infer and reason about design intentions from an early age. This is the first evidence that 2‐ and 3‐year‐olds not only take design intentions into account in object categorization, but that they do so even without explicit mention of the objects’ accidental or intentional histories. The results cast doubt on a proposal that young children's lexical categorization is based on automatic, non‐deliberative processes.     

Children's reliance on creator's intent in extending names for artifacts

When children learn a name for a novel artifact, they tend to extend the name to other artifacts that share the same shape—a phenomenon known as the shape bias. The present studies investigated an intentional account of this bias. In Study 1, 3-year-olds were shown two objects of the same shape, and were given an explanation for why the objects were the same shape even though they were intended to be different kinds. The shape bias disappeared in children provided with this explanation. In Study2, 3-year-olds were shown triads of objects, and were either given no information about the function of a named target object, told the function that object could fulfill, or told the functions all three objects were intended to fulfill. Only in the third condition did children overcome a shape bias in favor of a function bias when extending the name of the target object. These findings indicate that 3-year-olds' shape bias results from intuitions about what artifacts were intended to be.     

Young children's rapid learning about artifacts

Tool use is central to interdisciplinary debates about the evolution and distinctiveness of human intelligence, yet little is actually known about how human conceptions of artifacts develop. Results across these two studies show that even 2-year-olds approach artifacts in ways distinct from captive tool-using monkeys. Contrary to adult intuition, children do not treat all objects with appropriate properties as equally good means to an end. Instead, they use social information to rapidly form enduring artifact categories. After only one exposure to an artifact's functional use, children will construe the tool as 'for' that particular purpose and, furthermore, avoid using it for another feasible purpose. This teleo-functional tendency to categorize tools by intentional use represents a precursor to the design stance - the adult-like tendency to understand objects in terms of intended function - and provides an early foundation for apparently distinctive human abilities in efficient long-term tool use and design.     

A developmental dissociation between category and function judgments about novel artifacts

Two studies investigated the relative importance of information about intended design and current use on judgments about the function (Experiment 1) or category (Experiment 2) of novel artifacts in preschool children and adults. Adults assigned function and name on the basis of information about design across all conditions, while children’s decisions about function dissociated from decisions about category. Function judgments (in both 4 and 6-year-olds) were neutral between design and current use, both when the current use was idiosyncratic (e.g. performed by just one agent) and conventional (performed by many people; Experiment 1). By contrast, where category judgments were required for the very same objects (Experiment 2), children named according to design intentions - but only if the alternate function was idiosyncratic. Judging function and assigning category are thus cognitive tasks that draw on different information across development, a fact that should be captured by theories of developing artifact concept structure.     

Artifacts and natural kinds: children's judgments about whether objects are owned

People's behavior in relation to objects depends on whether they are owned. But how do people judge whether objects are owned? We propose that people expect human-made objects (artifacts) to be more likely to be owned than naturally occurring objects (natural kinds), and we examine the development of these expectations in young children. Experiment 1 found that when shown pictures of familiar kinds of objects, 3-year-olds expected artifacts to be owned and inanimate natural kinds to be non-owned. In Experiments 2A and 2B, 3-6-year-olds likewise had different expectations about the ownership of unfamiliar artifacts and natural kinds. Children at all ages viewed unfamiliar natural kinds as non-owned, but children younger than 6 years of age only endorsed artifacts as owned at chance rates. In Experiment 3, children saw the same pictures but were also told whether objects were human-made. With this information provided, even 3-year-olds viewed unfamiliar artifacts as owned. Finally, in Experiment 4, 4- and 5-year-olds chose unfamiliar artifacts over natural kinds when judging which object in a pair belongs to a person, but not when judging which the person prefers. These experiments provide first evidence about how children judge whether objects are owned. In contrast to claims that children think about natural kinds as being similar to artifacts, the current findings reveal that children have differing expectations about whether they are owned.     

Effects of knowledge about cross-language equivalents on children's use of mutual exclusivity in interpreting novel labels

Young children seem to assume that words pick out mutually exclusive object categories. This assumption of mutual exclusivity can be useful in word learning, but it is fallible. This study examined the effects of knowledge about cross-language equivalents on children's use of mutual exclusivity in interpreting a novel label coming from a foreign language and in interpreting a novel label within their first language. It was found that 4-year-olds with such knowledge suspended the assumption of mutual exclusivity in interpreting a novel label coming from a foreign language. Furthermore, they were willing to accept multiple labels for an object even within a language, as long as the context suggested that they should do so. In contrast, 3-year-olds did not seem to make use of such knowledge in either case. Thus, it appeared that 4-year-olds could make use of knowledge about language to fine tune the use of mutual exclusivity, but that this seemed to be difficult for 3-year-olds.     

The downside of categories

One of the primary uses of categories is to draw inferences about novel objects based on their category membership. In a recent study, Lagnado and Shanks show that people make different inferences about an object depending on whether they first categorize the object at a general or specific level. Indeed, their inference changes even though they have been given no information about the object. This finding reveals limitations of category-based induction.     

A Mutually Facilitative Relationship Between Learning Names and Learning Concepts in Preschool Children: The Case of Artifacts

Two studies investigated the relationship between learning names and learning concepts in preschool children. More specifically, we focused on the relationship between learning the names and learning the intended functions of artifacts, given that the intended function of an artifact is generally thought to constitute core conceptual information about an artifact's category. We asked whether learning the intended function of a novel artifact facilitates retention of its name and whether learning the name of a novel artifact prompts the search for information about its intended function. In Experiment 1, 3- and 4-year-old children better retained the names of novel artifacts when the intended functions of these artifacts were revealed. The comparison condition involved providing perceptually relevant and conceptually irrelevant information about the objects. In Experiment 2, 4-year-old children who were provided with the names of novel artifacts were more likely to seek out information about the objects' functions than children provided with conceptually irrelevant information about the artifacts. Together, the studies demonstrate the intimate and mutually facilitative relationship between names and concepts in young children.     

Young Children's Sensitivity to Speaker Gender When Learning From Others

This research explores whether young children are sensitive to speaker gender when learning novel information from others. Four- and 6-year-olds (N = 144) chose between conflicting statements from a male versus a female speaker (Studies 1 and 3) or decided which speaker (male or female) they would ask (Study 2) when learning about the functions of novel objects. Some objects were in gender-typing colors (light pink or navy blue), and some were in a gender-ambiguous color (yellow). The results indicated that children did use speaker gender to guide their learning, by either consistently choosing to agree with the speakers of their own gender or making choices that are associated with gender stereotypes about color. The findings are discussed in relation to how in-group preference and stereotype attributions might influence children's learning from others.     

Developmental differences in shape processing

Considerable evidence indicates that shape similarity plays a major role in object recognition, identification and categorization. However, little is known about shape processing and its development. Across four experiments, we addressed two related questions. First, what makes objects similar in shape? Second, how does the processing of shape similarity develop? We specifically asked whether children and adults determine shape similarity by using categories (e.g., straight vs. curved), as proposed by Biederman (1987), or whether they treat all shape variability uniformly, as proposed by Ullman (1998). Findings from Experiments 1 and 2 suggest that adults and 7-year-olds generally engage in a process in which they impose categories on shape variation and judge objects that fall within those categories as being similar in shape. Four-year-olds are far less likely to engage in such a process. Experiments 3 and 4 address whether 4-year-olds are more likely to treat shape similarity categorically (as older children and adults do) when the objects are given familiar names, functions, and internal properties. Naming did lead to more advanced treatment of shape similarity in some cases. Overall, these findings provide evidence of developmental differences in shape processing and suggest that knowledge of abstract properties of objects may affect the calculation of shape similarity.     

Preschoolers’ behavioural reenactment of “failed attempts”: The roles of intention-reading,emulation and mimicry

To clarify the nature of the social cognitive skills involved in preschoolers’ reenactment of actions on objects, we studied 31- and 41-month-old children's reenactment of intended acts (“failed attempts”) in Meltzoff's (Meltzoff, A. N. (1995). Understanding the intentions of others: Reenactment of intended acts by 18-month-old children. Developmental Psychology, 31, 838–850) behavioural reenactment paradigm. Measuring children's first action, performance of target acts was similar in a novel Emulation Learning condition to that seen in the Failed Attempt condition. In the Emulation Learning condition, children did not see the adult's manipulation and their response was likely to have been based on the end state specifying the object's key affordances. Both 31- and 41-month-old children also copied the control acts they had observed in the Adult Manipulation condition. However, 41-month-old but not 31-month-old children reproduced the failed attempt actions in the Failed Attempt condition. This pattern of findings suggests that, whilst 2- to 3-year-olds mimic adults’ actions when these actions do not trigger alternative object affordances, only in the third year of life will children mimic adults’ actions when these actions simultaneously trigger such affordances. Reenactment of actions on objects involves a number of social cognitive processes and exceptional care in the design of experiments is required to determine the roles played by intention-reading, emulation, and mimicry.     

Toddlers view artifact function normatively

When children use objects like adults, are they simply tracking regularities in others’ object use, or are they demonstrating a normatively defined awareness that there are right and wrong ways to act? This study provides the first evidence for the latter possibility. Young 2- and 3-year-olds (n = 32) learned functions of 6 artifacts, both familiar and novel. A puppet subsequently used the artifacts, sometimes in atypical ways, and children's spontaneous reactions were coded. Children responded normatively to non-designed uses (e.g., protesting, tattling), although the effect was stronger among older children. Reactions were identical for novel and familiar items, underscoring how rapidly tool-function mappings are formed. Results depict toddlers as already sensitive to the uniquely human, normative nature of tool use.     

Core knowledge and its limits: The domain of food

Adults, preschool children, and nonhuman primates detect and categorize food objects according to substance information, conveyed primarily by color and texture. In contrast, they perceive and categorize artifacts primarily by shape and rigidity. The present experiments investigated the origins of this distinction. Using a looking time procedure, Experiment 1 extended previous findings that rhesus macaques (Macaca mulatta) generalize learning about novel food objects by color over changes in shape. Six additional experiments then investigated whether human infants show the same signature patterns of perception and generalization. Nine-month-old infants failed to detect food objects in accord with their intrinsic properties, in contrast to rhesus monkeys tested in previous research with identical displays. Eight-month-old infants did not privilege substance information over other features when categorizing foods, even though they detected and remembered this information. Moreover, infants showed the same property generalization patterns when presented with foods and tools. The category-specific patterns of perception and categorization shown by human adults, children, and adult monkeys therefore were not found in human infants, providing evidence for limits to infants’ domains of knowledge.     

Was it designed to do that? Children's focus on intended function in their conceptualization of artifacts

Do young children who seek the conceptual kind of an artifact weigh the plausibility that a current function constitutes the function intended by the object designer? Three- and four-year-olds were encouraged to question adults about novel artifacts. After inquiring about what an object was, some children were shown a function that plausibly accounted for the structural features of the object; others were shown a possible, but implausible function. Children given implausible functions were less satisfied with these responses than those given plausible functions, as shown by their more persistent attempts to ask follow-up questions about function. Accordingly, preschoolers appear to take into account matters of intentional design when assigning artifacts to conceptual kinds.     

The Development of Symbolic Coordination: Representation of Imagined Objects,Executive Function,and Theory of Mind

Children's developing competence with symbolic representations was assessed in 3 studies. Study 1 examined the hypothesis that the production of imaginary symbolic objects in pantomime requires the simultaneous coordination of the dual representations of a dynamic action and a symbolic object. We explored this coordination of symbolic representations in 3- to 5-year-olds with a modified action pantomime task that employed both a "dynamic action + object" condition and a "hold + object" condition. Consistent with earlier research, production of imaginary symbolic objects rather than body-part-as-objects increased with age, although, even at age 5, children did not perform at adult levels. As hypothesized, children produced fewer body-part-as-object anchors when they were simply asked to hold an object, rather than perform a dynamic action with the object. Study 2 repeated the conditions of Study 1 and examined these conditions in relation to performance on the Dimensional Change Card Sort (DCCS) task. This study replicated the developmental findings of the earlier study and indicated a modest relation between pantomime and the DCCS, which disappeared with age partialled out. Study 3 examined the action pantomime task in relation to the DCCS, false belief, and appearance-reality with 3- to 5-year-olds. Though performance on the DCCS was related to theory of mind, production of imaginary symbolic objects in pantomime was not strongly related to theory of mind or the DCCS. Results are discussed in terms of children's developing reflective competence in coordinating symbolic representations.     

Can unpredicted outcomes be intended? The role of outcome-beliefs in children's judgments of intention

An adult-like concept of intention includes a deliberate action to achieve a goal and a belief that one's action (if successful) will cause the desired outcome. For example, good outcomes caused by accident or by chance are not believed to be caused intentionally. In two experiments, we asked whether children understand this connection between intentions and outcomes. Children played two games in which actions could produce unintended outcomes (i.e., causes were unplanned). Children sometimes received a desirable reward independent of intention. In Experiment 1, 4- and 5-year-olds mistakenly claimed they had intended the desirable outcome even when it was unexpected. Four-year-olds judged that they had not intended a deliberate action if it did not yield a rewarding outcome. Experiment 2 demonstrates that 6-year-olds seldom make these errors. The results suggest that 4- and 5-year-old children have not yet attained an adult-like concept of intention. Their inaccurate judgments regarding their intentions, given a rewarding yet unexpected outcome, can be explained by a positivity bias.     

the role of dimensional distinctiveness in children's and adults' artifact categorization

There are conflicting results as to whether preschool children categorize artifacts on the basis of physical or functional similarity. The present study investigated the effect of the relative distinctiveness of these dimensions in children's categorization. In a physical-distinctive condition, preschool children and adults were initially asked to categorize computer-animated artifacts whose physical appearances were more distinctive than their functions. In a function-distinctive condition, the functional dimension of objects was more distinctive than their physical appearances. Both conditions included a second stage of categorization in which both dimensions were equally distinctive. Participants in a control condition performed only this stage of categorization. Adults in all conditions and stages consistently categorized by functional similarity. In contrast, children's categorization was affected by the relative distinctiveness of the dimensions. Children may not have a priori specific beliefs about how to categorize novel artifacts, and thus may be more susceptible to contextual factors.     

When children ask, "What is it?" what do they want to know about artifacts?

When children ask, "What is it?" are they seeking information about what something is called or what kind of thing it is? To find out, we gave 2-, 3-, and 4-year-olds (32 at each age) the opportunity to inquire about unfamiliar artifacts. An ambiguous question was answered with a name or with functional information, depending on the group to which the children were assigned. Children were inclined to follow up with additional questions about the object when they had been told its name, but seemed satisfied with the answer when they had been told the object's function. Moreover, children in the name condition tended to substitute questions about function for ambiguous questions over the course of the session. These results indicate that children are motivated to discover what kinds of things novel artifacts are, and that young children, like adults, conceive of artifact kinds in terms of their functions.     

Reasoning about artifacts at 24 months: the developing teleo-functional stance

From the age of 2.5, children use social information to rapidly form enduring function-based artifact categories. The present study asked whether even younger children likewise constrain their use of objects according to teleo-functional beliefs that artifacts are "for" particular purposes, or whether they use objects as means to any desired end. Twenty-four-month-old toddlers learned about two novel tools that were physically equivalent but perceptually distinct; one tool was assigned implicit function information through a short demonstration. At test, toddlers returned to the demonstrated tool when asked to repeat the task, but, unlike older children, also used it for another task. Results imply that at 24 months, toddlers expect artifacts to have functions and proficiently use a model's intentional use to inform tool choices, suggesting cognition that differs from that of tool-using monkeys. However, their artifact representations are not yet specified enough to support exclusive patterns of tool use.     

Children's Conformity When Acquiring Novel Conventions: The Case of Artifacts

Prior research focused on children's acquisition of arbitrary social conventions (e.g., object labels) has revealed that both 3- and 4-year-old children conform to majority opinion. Two studies explored whether children show similar conformist tendencies when making category-based judgments about a less socially arbitrary domain that offers an objective basis for judgment: object functions. Three- and 4-year-old children watched a video in which two informants disagreed with a lone dissenter on the function of a novel artifact. Children were asked to categorize the object by stating with whom they agreed. The plausibility of the majority's response was manipulated across test trials. Results demonstrated that children were more likely to agree with the majority when majority and minority opinions were equally plausible, especially when the majority demonstrated an overt consensus. However, 4-year-olds actively eschewed the majority opinion when it was implausible in context of the artifact's functional design. The current results indicate that expertise in a domain of conventional knowledge reduces conformist tendencies.