Children expect generic knowledge to be widely shared

The role of exceptions in children's and adults' judgments about generic statements

Generic statements (e.g., "Ducks lay eggs") provide generalizations about kinds that can be judged as true, even in the face of exceptions. Although past research has focused on the positive evidence that justifies a generic, little work has explored the role of evidence that does not match the generic claim (e.g., ducks that do not lay eggs). The current studies aim to understand how different types of exceptions may differentially undermine generic claims. In Studies 1 and 2, adults (n = 560) and children ages 5-11 (n = 141) were asked to judge the truth of generic statements about fictitious animal kinds (e.g., Wugs have blue horns). Accompanying each statement was a set of 6 kind members, some of which displayed the target property (e.g., blue horns), and others of which displayed either an alternative property (e.g., red horns), or an absence of the property (e.g., no horns). Study 1 found that adults were less likely to endorse generic statements when non-matching examples displayed an alternative property than when they displayed an absence of the property. Study 2 indicated that children as well as adults were less likely to endorse generic statements when presented with alternative evidence, regardless of the salience of the alternative. Study 3 replicated these findings with a more sensitive task in which adults (n = 120) and children (n = 97) were asked to choose between sets with either alternative or absence evidence. These studies provide the first evidence that children and adults attend to non-matching evidence when making judgments about generic statements, interpret alternative evidence to be stronger counterevidence than absence evidence, and do not use the salience of alternative properties to determine the strength of alternative evidence. We discuss the implications of this work for problematic generic claims in language and thought.

Who Peeked? Children Infer the Likely Cause of Improbable Success

Some outcomes are brought about by intentional agents with access to information and others are not. Children use a variety of cues to infer the causes of outcomes, such as statistical reasoning (e.g., the probability of the outcome) and theory of mind (e.g., a person's perceptual access, preferences, or knowledge). Here we show that children use these cues to infer cheating, a finding which informs our understanding of the flexibility of children's theory of mind. In four experiments (N = 444), 4- to 7-year-olds saw vignettes about blindfolded agents retrieving 10 gumballs from a distribution of yummy and yucky gumballs. Children were then asked if agents were really blindfolded or had peeked. We manipulated the probability of the outcome (i.e., the correspondence between the distribution sampled from and the outcome produced) and the ordering of the outcome was patterned (e.g., five yummy then five yucky) or haphazard. From age 5, children began to use both cues to infer cheating, and also showed signs of flexibly integrating these cues. Together, these findings show that young children can detect cheaters, and that their theory of mind reasoning is flexible and not based on simple and rigid rules (e.g., equating not-seeing with failure). The findings also suggest that children use probabilistic reasoning to infer knowledge.

Children's expectations about the stability of others' knowledge and preference states

It is a crucial ability to predict others' psychological states across time and contexts. Focusing on cultural inventions such as songs and stories, we contrasted children's attributions of stability with others' knowledge and preference states across time and space and whether these attributions change as a function of children's familiarity with the known/liked items. Children (91 4-year-olds and 97 6-year-olds) were introduced to characters who knew or liked a song, a story, a game and a dance that were either novel or familiar. Children were asked whether the characters would still know/like these when they move to another city or when they grow up to be an adult. Both age groups expected these attributes to be more durable in the moving scenario compared with the growing-up scenario, but this trend became more robust with age. Whereas overall children did not judge knowledge as more durable than preferences, children found knowledge to be more enduring with age. The 6-year-olds' stability attributions also increased when known/liked items were familiar. These results suggest that, across the preschool years, children become more nuanced in their predictions about the future forms of knowledge and preference states.

Toddlers do not preferentially transmit generalizable information to others

Children actively and selectively transmit information to others based on the type of information and the context during learning. Four- to 7-year-old children preferentially transmit generalizable information in teaching-like contexts. Although 2-year-old children are able to distinguish between generalizable and non-generalizable information, it is not known whether they likewise transmit generalizable information selectively. We designed a behavioral study to address this question. Two-year-old children were presented with three novel boxes, identical except for their color. In each box, one of two equally salient actions led to a generalizable outcome (e.g., playing a [different] tune in each box), whereas the other led to a non-generalizable outcome (e.g., turning on a light, vibrating the box, or making a noise). In the discovery phase, children had a chance to discover the functions of each box presented one-by-one. Then, in the exploration phase, they were given the opportunity to independently explore all three boxes presented together. Finally, in the transmission phase, an ignorant recipient entered the room and asked the child to show them how these toys work. We measured whether children preferentially transmitted either generalizable or non-generalizable information when they were asked to demonstrate the function of the toys to a naïve adult. We found that children did not display any preference for transmitting generalizable information. These findings are discussed with respect to toddlers' selectivity in transmitting information but also the development of sensitivity to information generalizability. RESEARCH HIGHLIGHT: Young children transmit information to others and do so with some degree of selectivity to a variety of factors. Generalizability is an important factor affecting information transmission, and older children tend to associate generalizable information with teaching-like interactions. We tested whether toddlers selectively transmitted it to others over non-generalizable information. We found that toddlers do not show a preference to transmit generalizable over non-generalizable information.

The influence of language input on 3-year-olds' learning about novel social categories

There is considerable variability in the social categories that children essentialize and the types of expectations children form about these categories, suggesting children's essentialist beliefs are shaped by environmental input. Prior studies have shown that exposure to generic statements about a social category promotes essentialist beliefs in 4.5- to 8-year-old children. However, by this age children form essentialist beliefs quite robustly, and thus it is unclear whether generic statements impact children's expectations about social categories at younger ages when essentialist beliefs first begin to emerge. Moreover, in prior studies the generic statements were delivered by an experimenter and carefully controlled, and thus it is unclear whether these statements would have the same impact if they occurred in a somewhat less constrained setting, such as parents reading a picture book to their child. The current study addressed these open questions by investigating whether generic statements delivered during a picture-book interaction with their parents influenced 3-year-olds' expectations about members of a novel social category. Our results showed that children who heard generic statements during the picture-book interaction used social-group membership to make inferences about the likely behavior of a novel category member, whereas children who were not exposed to generic statements did not. These findings suggest that as early as 3 years of age, children's expectations about social categories are influenced by generic statements that occur during brief parent-child interactions.

Young children expect pretend object identities to be known only by their partners in joint pretence

The present study examined whether three-year-old children (age = 42-48 months, n = 57; 31 boys) understand that object identities stipulated during pretend play could only be known by people witnessing the stipulation. Children participated in pretend scenarios that included some objects and two experimenters. Two pretend episodes corresponded to an object: one connected to its conventional function, the other to a pretend identity made-up on the spot. These episodes happened either in the presence or absence of the other person. In the test phase, this experimenter expressed an intention to do something with an object and asked for a 'missing' prop. The prediction was that in case she was present previously, children would be more likely to select the prop corresponding to a pretence stipulation, compared to when she was absent. The results confirmed this pattern: in the absent condition, 68.42% of the participants chose the prop connected to the conventional use of the object, while 31.58% chose the prop corresponding to its identity stipulated in pretend play. It seems that preschool aged children refrain from generalizing their knowledge about the pretend identity of an object, in case their interactive partner could not know of this identity.

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.

The social meaning of common knowledge across development

Common knowledge can be a potent sign of shared social attributes among people, but not all knowledge is socially meaningful to the same extent. For instance, compared to shared knowledge of cultural practices, knowledge of self-evident facts might be a poorer indicator of shared group membership among individuals. Two studies explored adults' and 6-to-9 years old children's social inferences based on what others know as well as their sensitivity to the distinctions in the diagnostic potential of different kinds of knowledge. Participants were presented with targets who were knowledgeable about familiar things that are either culture-specific (e.g., a traditional dance) or general (e.g., a self-evident fact), and asked to make inferences about their language and where they live. Adults and 8-year-olds privileged culture-specific knowledge over general knowledge when making both kinds of inferences about the targets, whereas 6-year-olds did not distinguish between the two knowledge types. Thus, what others know is socially meaningful from early in life, and across development, children become increasingly aware of the diagnostic potential of culture-specific knowledge when making social inferences about others. These findings suggest novel social implications of knowledge assessment.

Toddlers and Preschoolers Understand That Some Preferences Are More Subjective Than Others

Four experiments examined Canadian 2- to 3-year-old children's (N = 224; 104 girls, 120 boys) thoughts about shared preferences. Children saw sets of items, and identified theirs and another person's preferences. Children expected that food preferences would be more likely to be shared than color preferences, regardless of whether the items were similar or different in appeal (Experiments 1-3). A final study replicated these findings while also exploring children's expectations about activity and animal preferences. Across all studies, children expected shared preferences at surprisingly low rates (never higher than chance). Overall, these findings suggest that young children understand that some preferences are more subjective than others, and that these expectations are driven by beliefs about domains of preferences.

Children and Adults Selectively Attribute Shared Cultural Knowledge to Speakers of the Same Language

Children's and adults' attributions of shared knowledge of and shared preference for songs were investigated across two prominent social categories: language and gender. Both attributions indicate similarity among individuals but shared cultural knowledge can be more informative about common social history than shared preference, as it is mainly transferred through social interactions within cultures, while preferences can have various sources. Both 5- to 6-year-old children (N = 60) and adults (N = 160) generalized knowledge of songs across individuals who speak the same-language rather than same-gender individuals. In contrast, preference for songs was not systematically generalized across either category. Thus, individuals selectively infer shared cultural knowledge among same-language speakers, suggesting an early emerging link between shared knowledge and cultural boundaries.

When Your Kind Cannot Live Here: How Generic Language and Criminal Sanctions Shape Social Categorization

Using generic language to describe groups (applying characteristics to entire categories) is ubiquitous and affects how children and adults categorize other people. Five-year-olds, 8-year-olds, and adults ( N = 190) learned about a novel social group that separated into two factions (citizens and noncitizens). Noncitizens were described in either generic or specific language. Later, the children and adults categorized individuals in two contexts: criminal (individuals labeled as noncitizens faced jail and deportation) and noncriminal (labeling had no consequences). Language genericity influenced decision making. Participants in the specific-language condition, but not those in the generic-language condition, reduced the rate at which they identified potential noncitizens when their judgments resulted in criminal penalties compared with when their judgments had no consequences. In addition, learning about noncitizens in specific language (vs. generic language) increased the amount of matching evidence participants needed to identify potential noncitizens (preponderance standard) and decreased participants' certainty in their judgments. Thus, generic language encourages children and adults to categorize individuals using a lower evidentiary standard regardless of negative consequences for presumed social-group membership.

How language shapes the cultural inheritance of categories

It is widely recognized that language plays a key role in the transmission of human culture, but relatively little is known about the mechanisms by which language simultaneously encourages both cultural stability and cultural innovation. This paper examines this issue by focusing on the use of language to transmit categories, focusing on two universal devices: labels (e.g., shark, woman) and generics (e.g., "sharks attack swimmers"; "women are nurturing"). We propose that labels and generics each assume two key principles: norms and essentialism. The normative assumption permits transmission of category information with great fidelity, whereas essentialism invites innovation by means of an open-ended, placeholder structure. Additionally, we sketch out how labels and generics aid in conceptual alignment and the progressive "looping" between categories and cultural practices. In this way, human language is a technology that enhances and expands the categorization capacities that we share with other animals.

Children's Pragmatic Inferences as a Route for Learning About the World

This study investigated whether children can infer category properties based on how a speaker describes an individual (e.g., saying something is a "small zib" implies that zibs are generally bigger than this one). Three- to 5-year-olds (N = 264) from a university preschool and a children's museum were tested on their ability to make this sort of contrast inference. Children made some inferences from adjective choice alone (Experiment 1); performance increased as more cues to contrast were added (Experiments 2 and 3). Control studies show that these findings are not due to the particular properties used or the structure of these tasks (Experiments 4 and 5). These findings suggest that sensitivity to speakers' production choices may help children learn about the world.

Knowledge Central: A Central Role for Knowledge Attributions in Social Evaluations

Five experiments ( N = 1710) demonstrate the central role of knowledge attributions in social evaluations. In Experiments 1–3, we manipulated whether an agent believes, is certain of, or knows a true proposition and asked people to rate whether the agent should perform a variety of actions. We found that knowledge, more so than belief or certainty, leads people to judge that the agent should act. In Experiments 4–5, we investigated whether attributions of knowledge or certainty can explain an important finding on how people act based on statistical evidence, known as “the Wells effect”. We found that knowledge attributions, but not certainty attributions, mediate this effect on decision making.

Fitting the Message to the Listener: Children Selectively Mention General and Specific Facts

In three experiments, two hundred and ninety-seven 4- to 6-year-olds were asked to describe objects to a listener, and their answers were coded for the presence of general and specific facts. In Experiments 1 and 2, the listener's knowledge of the kinds of objects was manipulated. This affected references to specific facts at all ages, but only affected references to general facts in children aged 5 and older. In Experiment 3, children's goal in communicating was either pedagogical or not. Pedagogy influenced references to general information from age 4, but not references to specific information. These findings are informative about how children vary general and specific information in conversation, and suggest that listeners' knowledge and children's pedagogical goals influenced children's responses via different mechanisms.

Generics license 30-month-olds' inferences about the atypical properties of novel kinds

We examined whether the distinction between generic and nongeneric language provides toddlers with a rapid and efficient means to learn about kinds. In Experiment 1, we examined 30-month-olds' willingness to extend atypical properties to members of an unfamiliar category when the properties were introduced in 1 of 3 ways: (a) using a generic noun phrase ("Blicks drink ketchup"); (b) using a nongeneric noun phrase ("These blicks drink ketchup"); and (c) using an attentional phrase ("Look at this"). Hearing a generic noun phrase boosted toddlers' extension of properties to both the model exemplars and to novel members of the same category, relative to when a property had been introduced with a nongeneric noun phrase or an attentional phrase. In Experiment 2, properties were introduced with a generic noun phrase, and toddlers extended novel properties to members of the same-category, but not to an out-of-category object. Taken together, these findings demonstrate that generics highlight the stability of a feature and foster generalization of the property to novel within-category exemplars. (PsycINFO Database Record

Older (but not younger) preschoolers understand that knowledge differs between people and across time

We examined 3- to 5-year-olds' understanding of general knowledge (e.g., knowing that clocks tell time) by investigating whether (1) they recognize that their own general knowledge has changed over time (i.e., they knew less as babies than they know now), and (2) such intraindividual knowledge differences are easier/harder to understand than interindividual differences (i.e., Do preschoolers understand that a baby knows less than they do?). Forty-eight 3- to 5-year-olds answered questions about their current general knowledge ('self-now'), the general knowledge of a 6-month-old ('baby-now'), and their own general knowledge at 6 months ('self-past'). All age groups were significantly above chance on the self-now questions, but only 5-year-olds were significantly above chance on the self-past and baby-now questions. Moreover, children's performance on the baby-now and self-past questions did not differ. Our findings suggest that younger preschoolers do not fully appreciate that their past knowledge differs from their current knowledge, and that others may have less knowledge than they do. We situate these findings within the research on knowledge understanding, more specifically, and cognitive development, more broadly.

Developmental Changes in Cross-Situational Word Learning: The Inverse Effect of Initial Accuracy

Intuitively, the accuracy of initial word-referent mappings should be positively correlated with the outcome of learning. Yet recent evidence suggests an inverse effect of initial accuracy in adults, whereby greater accuracy of initial mappings is associated with poorer outcomes in a cross-situational learning task. Here, we examine the impact of initial accuracy on 4-year-olds, 10-year-olds, and adults. For half of the participants most word-referent mappings were initially correct and for the other half most mappings were initially incorrect. Initial accuracy was positively related to learning outcomes in 4-year-olds, had no effect on 10-year-olds' learning, and was inversely related to learning outcomes in adults. Examination of item learning patterns revealed item interdependence for adults and 4-year-olds but not 10-year-olds. These findings point to a qualitative change in language learning processes over development.

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.

The inherence heuristic: An intuitive means of making sense of the world, and a potential precursor to psychological essentialism

We propose that human reasoning relies on aninherence heuristic, an implicit cognitive process that leads people to explain observed patterns (e.g., girls wear pink) predominantly in terms of the inherent features of their constituents (e.g., pink is a delicate color). We then demonstrate how this proposed heuristic can provide a unified account for a broad set of findings spanning areas of research that might at first appear unrelated (e.g., system justification, nominal realism, is–ought errors in moral reasoning). By revealing the deep commonalities among the diverse phenomena that fall under its scope, our account is able to generate new insights into these phenomena, as well as new empirical predictions. A second main goal of this article, aside from introducing the inherence heuristic, is to articulate the proposal that the heuristic serves as a foundation for the development of psychological essentialism. More specifically, we propose thatessentialism – which is the common belief that natural and social categories are underlain by hidden, causally powerful essences – emerges over the first few years of life as an elaboration of the earlier, and more open-ended, intuitions supplied by the inherence heuristic. In the final part of the report, we distinguish our proposal from competing accounts (e.g., Strevens's K-laws) and clarify the relationship between the inherence heuristic and related cognitive tendencies (e.g., the correspondence bias). In sum, this article illuminates a basic cognitive process that emerges early in life and is likely to have profound effects on many aspects of human psychology.