When hearsay trumps evidence: How generic language guides preschoolers’ inferences about unfamiliar things

Children's use of pragmatic inference to learn about the social world

Young children often endorse stereotypes-such as "girls are bad at math." We explore one mechanism through which these beliefs may be transmitted: via pragmatic inference. Specifically, we ask whether preschoolers and adults can learn about an unmentioned social group from what is said about another group, and if this inferential process is sensitive to the context of the utterance. Sixty-three- to five-year-old children and fifty-five adults were introduced to two novel social groups-Stripeys and Dotties-and witnessed a speaker praising abilities of one group (e.g., "the Stripeys are good at building chairs"). To examine the effect of context, we compared situations where the speaker was knowledgeable about the abilities of both groups, and had been queried about the performance of both groups (broad context), versus situations where the speaker was only knowledgeable about one group and was only asked about that group (narrow context). Both preschoolers and adults were sensitive to context: they were more likely to infer that the group not mentioned by the speaker was relatively unskilled, and were more confident about it, in the broad context condition. Our work integrates research in language development and social cognitive development and demonstrates that even young children can "read between the lines," utilizing subtle contextual cues to pick up negative evaluative messages about social groups even from statements that ostensibly do not mention them at all. HIGHLIGHTS: After hearing a speaker praise one group's skill, preschoolers and adults infer that an unmentioned group is relatively less skilled across a range of measures. These inferences are context-sensitive and are stronger when the speaker is knowledgeable of and asked about both groups' skill level. These results shed light on how children may indirectly learn negative stereotypes, especially ones that adults are unlikely to state explicitly. This work extends previous research on children's developing pragmatic ability, as well as their ability to learn about the social world from language.

Language Signaling High Proportions and Generics Lead to Generalizing, but Not Essentializing, for Novel Social Kinds

Generics (e.g., "Dogs bark") are thought by many to lead to essentializing: to assuming that members of the same category share an internal property that causally grounds shared behaviors and traits, even without evidence of such a shared property. Similarly, generics are thought to increase generalizing, that is, attributing properties to other members of the same group given evidence that some members of the group have the property. However, it is not clear from past research what underlies the capacity of generic language to increase essentializing and generalizing. Is it specific to generics, or are there broader mechanisms at work, such as the fact that generics are terms that signal high proportions? Study 1 (100 5-6 year-olds, 140 adults) found that neither generics, nor high-proportion quantifiers ("most," "many") elicited essentializing about a novel social kind (Zarpies). However, both generics and high-proportion quantifiers led adults and, to a lesser extent, children, to generalize, with high-proportion quantifiers doing so more than generics for adults. Specifics ("this") did not protect against either essentializing or generalizing when compared to the quantifier "some." Study 2 (100 5-6 year-olds, 112 adults) found that neither generics nor visual imagery signaling high proportions led to essentializing. While generics increased generalizing compared to specifics and visual imagery signaling both low and high proportions for adults, there was no difference in generalizing for children. Our findings suggest high-proportion quantifiers, including generics, lead adults, and to some extent children, to generalize, but not essentialize, about novel social kinds.

Dichotomous thinking about social groups: Learning about one group can activate opposite beliefs about another group

Across three studies (N = 607), we examined people's use of a dichotomizing heuristic-the inference that characteristics belonging to one group do not apply to another group-when making judgments about novel social groups. Participants learned information about one group (e.g., "Zuttles like apples"), and then made inferences about another group (e.g., "Do Twiggums like apples or hate apples?"). Study 1 acted as a proof of concept: Eight-year-olds and adults (but not 5-year-olds) assumed that the two groups would have opposite characteristics. Learning about the group as a generic whole versus as specific individuals boosted the use of the heuristic. Study 2 and Study 3 (sample sizes, methods, and analyses pre-registered), examined whether the presence or absence of several factors affected the activation and scope of the dichotomizing heuristic in adults. Whereas learning about or treating the groups as separate was necessary for activating dichotomous thinking, intergroup conflict and featuring only two (versus many) groups was not required. Moreover, the heuristic occurred when participants made both binary and scaled decisions. Once triggered, adults applied this cognitive shortcut widely-not only to benign (e.g., liking apples) and novel characteristics (e.g., liking modies), but also to evaluative traits signaling the morals or virtues of a social group (e.g., meanness or intelligence). Adults did not, however, extend the heuristic to the edges of improbability: They failed to dichotomize when doing so would attribute highly unusual preferences (e.g., disliking having fun). Taken together, these studies indicate the presence of a dichotomizing heuristic with broad implications for how people make social group inferences.

Developmental Changes in Strategies for Gathering Evidence About Biological Kinds

How do people gather samples of evidence to learn about the world? Adults often prefer to sample evidence from diverse sources-for example, choosing to test a robin and a turkey to find out if something is true of birds in general. Children below age 9, however, often do not consider sample diversity, instead treating non-diverse samples (e.g., two robins) and diverse samples as equivalently informative. The current study (N = 247) found that this discontinuity stems from developmental changes in standards for evaluating evidence-younger children chose to learn from samples that best approximate idealized views of what category members are supposed to be like (e.g., the fastest cheetahs), with a gradual shift across age toward samples that cover more within-category variation (e.g., cheetahs of varying speeds). These findings have implications for the relation between conceptual structure and inductive reasoning, and for the mechanisms underlying inductive reasoning more generally.

Generalizing About Striking Properties: Do Glippets Love to Play With Fire?

Two experiments investigated whether 4- and 5-year-old children are sensitive to whether the content of a generalization is about a salient or noteworthy property (henceforth "striking") and whether varying the number of exceptions has any effect on children's willingness to extend a property after having heard a generalization. Moreover, they investigated how the content of a generalization interacts with exception tolerance. Adult data were collected for comparison. We used generalizations to describe novel kinds (e.g., "glippets") that had either a neutral (e.g., "play with toys") or a striking property (e.g., "play with fire") and measured how willing participants were to extend the property to a new instance of the novel kind. Experiment 1 demonstrated that both adults and children show sensitivity to strikingness in that striking properties were extended less than neutral ones, although children extended less than adults overall. The responses of both age groups were significantly different from chance. Experiment 2 introduced varying numbers of exceptions to the generalization made (minimal: 1 exception; maximal: 3 exceptions). Both adults and children extended both types of properties even in the face of exceptions, but to a lower degree than in Experiment 1. Striking properties were extended less than neutral ones, as in Experiment 1. We observed that the greater the number of exceptions, the lower the rates of extension we obtained, for both types of properties in adults, but only with striking properties in children. Children seemed to keep track of varying numbers of exceptions for striking properties, but their performance did not differ from chance. The findings underscore that 4- and 5-year-old children are sensitive to strikingness and to exception tolerance for generalizations and are developing toward an adult-like behavior with respect to the interplay between strikingness and exception tolerance when they learn about novel kinds. We discuss the implications of these results with regards to how children make generalizations.

Preferences for Explanation Generality Develop Early in Biology But Not Physics

One of the core functions of explanation is to support prediction and generalization. However, some explanations license a broader range of predictions than others. For instance, an explanation about biology could be presented as applying to a specific case (e.g., "this bear") or more generally across "all animals." The current study investigated how 5- to 7-year-olds (N = 36), 11- to 13-year-olds (N = 34), and adults (N = 79) evaluate explanations at varying levels of generality in biology and physics. Findings revealed that even the youngest children preferred general explanations in biology. However, only older children and adults preferred explanation generality in physics. Findings are discussed in light of differences in our intuitions about biological and physical principles.

Are stereotypes accurate? A perspective from the cognitive science of concepts

In his 2012 book, Jussim suggests that people's beliefs about various groups (i.e., their stereotypes) are largely accurate. We unpack this claim using the distinction between generic and statistical beliefs - a distinction supported by extensive evidence in cognitive psychology, linguistics, and philosophy. Regardless of whether one understands stereotypes as generic or statistical beliefs about groups, skepticism remains about the rationality of social judgments.

Children's generic interpretation of pretense

We report two experiments investigating how 3- to 5-year-olds learn general knowledge from pretend play-how they learn about kinds of things (e.g., information about dogs) from information about particular individuals in pretend play (a certain dog in a pretend scenario). Children watched pretend-play enactments in which animals showed certain behaviors or heard utterances conveying the same information. When children were subsequently asked about who shows the behavior, children who watched pretend play were more likely to give generic responses than were children who heard the utterances. These findings show that children generalize information from pretend play to kinds even without being prompted to think about kinds, that pretend play can be informative about familiar kinds, and also that pretend play is a more potent source for general knowledge than are utterances about individuals.

Reasoning about knowledge: Children's evaluations of generality and verifiability

In a series of experiments, we examined 3- to 8-year-old children's (N=223) and adults' (N=32) use of two properties of testimony to estimate a speaker's knowledge: generality and verifiability. Participants were presented with a "Generic speaker" who made a series of 4 general claims about "pangolins" (a novel animal kind), and a "Specific speaker" who made a series of 4 specific claims about "this pangolin" as an individual. To investigate the role of verifiability, we systematically varied whether the claim referred to a perceptually-obvious feature visible in a picture (e.g., "has a pointy nose") or a non-evident feature that was not visible (e.g., "sleeps in a hollow tree"). Three main findings emerged: (1) young children showed a pronounced reliance on verifiability that decreased with age. Three-year-old children were especially prone to credit knowledge to speakers who made verifiable claims, whereas 7- to 8-year-olds and adults credited knowledge to generic speakers regardless of whether the claims were verifiable; (2) children's attributions of knowledge to generic speakers was not detectable until age 5, and only when those claims were also verifiable; (3) children often generalized speakers' knowledge outside of the pangolin domain, indicating a belief that a person's knowledge about pangolins likely extends to new facts. Findings indicate that young children may be inclined to doubt speakers who make claims they cannot verify themselves, as well as a developmentally increasing appreciation for speakers who make general claims.

Children's Developing Intuitions About the Truth Conditions and Implications of Novel Generics Versus Quantified Statements

Generic statements express generalizations about categories and present a unique semantic profile that is distinct from quantified statements. This paper reports two studies examining the development of children's intuitions about the semantics of generics and how they differ from statements quantified by all, most, and some. Results reveal that, like adults, preschoolers (a) recognize that generics have flexible truth conditions and are capable of representing a wide range of prevalence levels; and (b) interpret novel generics as having near-universal prevalence implications. Results further show that by age 4, children are beginning to differentiate the meaning of generics and quantified statements; however, even 7- to 11-year-olds are not adultlike in their intuitions about the meaning of most-quantified statements. Overall, these studies suggest that by preschool, children interpret generics in much the same way that adults do; however, mastery of the semantics of quantified statements follows a more protracted course.

Generic Language Use Reveals Domain Differences in Children's Expectations about Animal and Artifact Categories

The goal of the present study was to explore domain differences in young children's expectations about the structure of animal and artifact categories. We examined 5-year-olds' and adults' use of category-referring generic noun phrases (e.g., "Birds fly") about novel animals and artifacts. The same stimuli served as both animals and artifacts; thus, stimuli were perceptually identical across domains, and domain was indicated exclusively by language. Results revealed systematic domain differences: Children and adults produced more generic utterances when items were described as animals than artifacts. Because the stimuli were novel and lacking perceptual cues to domain, these findings must be attributed to higher-order expectations about animal and artifact categories. Overall, results indicate that by age 5, children are able to make knowledge-based domain distinctions between animals and artifacts that may be rooted in beliefs about the coherence and homogeneity of categories within these domains.

Representation of principled connections: a window onto the formal aspect of common sense conception

Nominal concepts represent things as tokens of types. Recent research suggests that we represent principled connections between the type of thing something is (e.g., DOG) and some of its properties (k-properties; e.g., having four legs for dogs) but not other properties (t-properties; e.g., being brown for dogs). Principled connections differ from logical, statistical, and causal connections. Principled connections license (i) the expectation that tokens of the type will generally possess their k-properties, (ii) formal explanations (i.e., explanation of the presence of k-properties in tokens of a type by reference to the type of thing it is), and (iii) normative expectations concerning the presence of k-properties in tokens of the type. The present paper investigates the hypothesis that representing principled connections requires representing properties as aspects of being the relevant kind of thing (Aspect Hypothesis). Experiment 1 provides a direct test of the Aspect Hypothesis. Experiments 2 and 3 provide indirect tests of the Aspect Hypothesis. All three experiments provide support for the Aspect Hypothesis. Experiment 4 investigates a prediction of the Aspect Hypothesis concerning the manner in which formal explanations are licensed by principled connections. Finally, Experiment 5 investigates a prediction of the Aspect Hypothesis concerning the nature of the normative expectations licensed by principled connections. Together these results provide strong evidence for the idea that representing principled connections involves representing a property as being an aspect of being a given kind of thing. The results also help clarify the manner in which formal explanation differs from other modes of explanation. Finally, the results of the experiments are used to motivate a proposal concerning the formal structure of the conceptual representations implicated by principled connections. This structure provides a domain-general way of structuring our concepts and embodies the perspective we take when we think and talk of things as being instances of a kind.

Generic language facilitates children's cross-classification

Four studies examined the role of generic language in facilitating 4- and 5-year-old children's ability to cross-classify. Participants were asked to classify an item into a familiar (taxonomic or script) category, then cross-classify it into a novel (script or taxonomic) category with the help of a clue expressed in either generic or specific language. Experiment 1 showed that generics facilitate 5-year-olds' and adults' cross-classification when expressed at an appropriate level of generalization (e.g., "foods," "birthday party things"), whereas Experiment 2 showed that such effects disappeared when labels were at an inappropriate level of generalization (e.g., "pizzas," "balloons"). Experiments 3 and 4 offered additional controls. Taken together, the findings demonstrate that language can guide and direct children's multiple categorizations.

Do lions have manes? For children, generics are about kinds rather than quantities

Generic statements (e.g., "Lions have manes") make claims about kinds (e.g., lions as a category) and, for adults, are distinct from quantificational statements (e.g., "Most lions have manes"), which make claims about how many individuals have a given property. This article examined whether young children also understand that generics do not depend purely on quantitative information. Five-year-olds (n = 36) evaluated pairs of questions expressing properties that were matched in prevalence but varied in whether adults accept them as generically true (e.g., "Do lions have manes?" [true] vs. "Are lions boys?" [false]). Results demonstrated that children evaluate generics based on more than just quantitative information. Data suggest that even young children recognize that generics make claims about kinds.

The role of external sources of information in children's evaluative food categories

Evaluative food categories are value-laden assessments which reflect the healthfulness and palatability of foods (e.g., healthy/unhealthy, yummy/yucky). In a series of three studies, this research examines how 3- to 4-year-old children (N = 147) form evaluative food categories based on input from external sources of information. The results indicate that children prefer to ask a mom and teacher over a cartoon and child for information about the evaluative status of foods. However, children are cautious to accept information about healthy foods from all of the external sources compared to unhealthy, yummy, and yucky foods. The results also indicate that providing information about the positive taste of healthy foods helps to encourage children to select healthy foods to eat. Taken together, these results have potential implications for children's health and nutrition education.

Two-year-olds use the generic/nongeneric distinction to guide their inferences about novel kinds

These studies investigated two hundred and forty-four 24- and 30-month-olds' sensitivity to generic versus nongeneric language when acquiring knowledge about novel kinds. Toddlers were administered an inductive inference task, during which they heard a generic noun phrase (e.g., "Blicks drink milk") or a nongeneric noun phrase (e.g., "This blick drinks milk") paired with an action (e.g., drinking) modeled on an object. They were then provided with the model and a nonmodel exemplar and asked to imitate the action. After hearing nongeneric phrases, 30-month-olds, but not 24-month-olds, imitated more often with the model than with the nonmodel exemplar. In contrast, after hearing generic phrases, 30-month-olds imitated equally often with both exemplars. These results suggest that 30-month-olds use the generic/nongeneric distinction to guide their inferences about novel kinds.

The generic/nongeneric distinction influences how children interpret new information about social others

These studies investigate how the distinction between generic sentences (e.g., "Boys are good at math") and nongeneric sentences (e.g., "Johnny is good at math") shapes children's social cognition. These sentence types are hypothesized to have different implications about the source and nature of the properties conveyed. Specifically, generics may be more likely to imply that the referred-to properties emerge naturally from an internal source, which may cause these properties to become essentialized. Four experiments (N = 269 four-year-olds and undergraduates) confirmed this hypothesis but also suggested that participants only essentialize the information provided in generic form when this construal is consistent with their prior theoretical knowledge. These studies further current understanding of language as a means of learning about others.

Child categorization

Categorization is a process that spans all of development, beginning in earliest infancy yet changing as children's knowledge and cognitive skills develop. In this review article, we address three core issues regarding childhood categorization. First, we discuss the extent to which early categories are rooted in perceptual similarity versus knowledge-enriched theories. We argue for a composite perspective in which categories are steeped in commonsense theories from a young age but also are informed by low-level similarity and associative learning cues. Second, we examine the role of language in early categorization. We review evidence to suggest that language is a powerful means of expressing, communicating, shaping, and supporting category knowledge. Finally, we consider categories in context. We discuss sources of variability and flexibility in children's categories, as well as the ways in which children's categories are used within larger knowledge systems (e.g., to form analogies, make inferences, or construct theories). Categorization is a process that is intrinsically tied to nearly all aspects of cognition, and its study provides insight into cognitive development, broadly construed. WIREs Cogn Sci 2011 2 95-105 DOI: 10.1002/wcs.96 For further resources related to this article, please visit the WIREs website.

Effects of generic language on category content and structure

We hypothesized that generic noun phrases ("Bears climb trees") would provide important input to children's developing concepts. In three experiments, four-year-olds and adults learned a series of facts about a novel animal category, in one of three wording conditions: generic (e.g., "Zarpies hate ice cream"), specific-label (e.g., "This zarpie hates ice cream"), or no-label (e.g., "This hates ice cream"). Participants completed a battery of tasks assessing the extent to which they linked the category to the properties expressed, and the extent to which they treated the category as constituting an essentialized kind. As predicted, for adults, generics training resulted in tighter category-property links and more category essentialism than both the specific-label and no-label training. Children also showed effects of generic wording, though the effects were weaker and required more extensive input. We discuss the implications for language-thought relations, and for the acquisition of essentialized categories.

Early word-learning entails reference, not merely associations

Recent years have witnessed a resurgence of classic tensions concerning the fundamental nature of human knowledge and the processes underlying its acquisition. This tension, especially evident in research on the acquisition of words and concepts, arises when researchers pit one type of content against another (perceptual versus conceptual) and one type of process against another (associative versus theory-based). But these dichotomies are false; they rest upon insufficient consideration of the structure and diversity of the words and concepts that we naturally acquire. As infants and young children establish categories and acquire words to describe them, they take advantage of both perceptual and conceptual information, and relate this to both the (rudimentary) theories they hold and the statistics that they witness.

Generic language and judgements about category membership: Can generics highlight properties as central?

Many languages distinguish generic utterances (e.g., "Tigers are ferocious") from non-generic utterances (e.g., "Those tigers are ferocious"). Two studies examined how generic language specially links properties and categories. We used a novel-word extension task to ask if 4- to 5-year-old children and adults distinguish between generic and specific language, and judge that predicating a property of a depicted novel animal using generic language (e.g., "Bants have stripes"), rather than non-generic language (e.g., "This bant has stripes") implies a more kind-relevant connection between category and property. Participants were asked to endorse an extension of the label taught to a novel animal matching the target instance on either overall similarity or the mentioned property. Wording was found to have a significant effect on responses for both age groups. Altogether, the results of these studies suggest that the generic may be a default interpretation for young children, who need to learn the semantics of specific and set-theoretic expressions.