Infants Understand How Testimony Works

When is it appropriate to ask a question? The role of age, social context, and personality

How do children decide when it is appropriate to ask a question? In Study 1 (preregistered), 50 4- and 5-year-olds, 50 7- and 8-year-olds, and 100 adults watched vignettes featuring a child who had a question, and participants indicated whether they thought the child should ask the question "right now." Both adults and children endorsed more question-asking to a well-known informant than to an acquaintance and to someone doing nothing than to someone busy working or busy socializing. However, younger children endorsed asking questions to someone who was busy more often than older children and adults. In addition, Big Five personality traits predicted endorsement of question-asking. In Study 2 (preregistered, N = 500), mothers' self-reports showed that children's actual question-asking varied with age, informant activity, and informant familiarity in ways that paralleled the results of Study 1. In Study 3 (N = 100), we examined mothers' responses to their children's question-asking and found that mothers' responses to their children's question-asking varied based on the mother's activity. In addition, mothers high in authoritarianism were less likely to answer their children's questions when they were busy than mothers low in authoritarianism. In sum, across three studies, we found evidence that the age-related decline in children's question-asking to their parents reflects a change in children's reasoning about when it is appropriate to ask a question.

A transdisciplinary view on curiosity beyond linguistic humans: animals, infants, and artificial intelligence

Curiosity is a core driver for life-long learning, problem-solving and decision-making. In a broad sense, curiosity is defined as the intrinsically motivated acquisition of novel information. Despite a decades-long history of curiosity research and the earliest human theories arising from studies of laboratory rodents, curiosity has mainly been considered in two camps: 'linguistic human' and 'other'. This is despite psychology being heritable, and there are many continuities in cognitive capacities across the animal kingdom. Boundary-pushing cross-disciplinary debates on curiosity are lacking, and the relative exclusion of pre-linguistic infants and non-human animals has led to a scientific impasse which more broadly impedes the development of artificially intelligent systems modelled on curiosity in natural agents. In this review, we synthesize literature across multiple disciplines that have studied curiosity in non-verbal systems. By highlighting how similar findings have been produced across the separate disciplines of animal behaviour, developmental psychology, neuroscience, and computational cognition, we discuss how this can be used to advance our understanding of curiosity. We propose, for the first time, how features of curiosity could be quantified and therefore studied more operationally across systems: across different species, developmental stages, and natural or artificial agents.

The breadth and specificity of 18-month-old's infant-initiated interactions in naturalistic home settings

Infants actively initiate social interactions aiming to elicit different types of responses from other people. This study aimed to document a variety of communicative interactions initiated by 18-month-old Turkish infants from diverse SES (N = 43) with their caregivers in their natural home settings. The infant-initiated interactions such as use of deictic gestures (e.g., pointing, holdouts), action demonstrations, vocalizations, and non-specific play actions were coded from video recordings and classified into two categories as need-based and non-need-based. Need-based interactions were further classified as a) biological (e.g., feeding); b) socio-emotional (e.g., cuddling), and non-need-based interactions (i.e., communicative intentions) were coded as a) expressive, b) requestive; c) information/help-seeking; d) information-giving. Infant-initiated non-need-based (88%) interactions were more prevalent compared to need-based interactions (12%). Among the non-need-based interactions, 50% aimed at expressing or sharing attention or emotion, 26% aimed at requesting an object or an action, and 12% aimed at seeking information or help. Infant-initiated information-giving events were rare. We further investigated the effects of familial SES and infant sex, finding no effect of either on the number of infant-initiated interactions. These findings suggest that at 18 months, infants actively communicate with their social partners to fulfil their need-based and non-need-based motivations using a wide range of verbal and nonverbal behaviors, regardless of their sex and socio-economic background. This study thoroughly characterizes a wide and detailed range of infant-initiated spontaneous communicative bids in hard-to-access contexts (infants' daily lives at home) and with a traditionally underrepresented non-WEIRD population.

Critical Thinking in Ethical and Neutral Settings in Gifted Children and Non-Gifted Children

The present study examined the performance on five phases of critical thinking in gifted and nongifted children in two settings: ethical and neutral. Ninety-one children, 32 gifted (8-10 years old), 32 normally developing children matched for chronological age (8-10 years old) and 27 normally developing children matched for mental age (12-13 years old) completed critical thinking tasks. The findings confirmed that intellectually gifted children had higher critical thinking capacity than typically developing children. The results reveal that the basic factor determining best performances in critical thinking is mental age and not chronological age. However, critical thinking ability was the same in ethical and neutral settings. Analysis of the phases of critical thinking show that the first and the third phase, clarification and evaluation, specifically differentiates gifted from nongifted children. These phases refer to the ability to understand the type of problem rapidly and to assess the credibility of statements and to assess the logical strength of the actual or intended inferential relationships among statements, descriptions, questions or other forms of representation.

Young children share imagined possibilities: evidence for an early-emerging human competence

Children's ability to reason about junctures leading to two different destinations emerges slowly, with convergent evidence for a conceptual watershed at approximately 4 years. Young children and great apes misrepresent such junctures, planning for only one expected outcome. However, singular possibilities, as opposed to two mutually exclusive possibilities, are readily imagined, shared and acted upon by 2- and 3-year-olds. Analysis of three domains supports this claim. First, 2- and 3-year-olds respond appropriately to pretend spatial displacements enacted for them by a play partner. Second, they not only respond accurately to claims regarding an alleged but unwitnessed spatial displacement, they also ask their interlocutors about the possible whereabouts of missing objects and absent persons. Third, in ordinary conversation, they appropriately mark some of their assertions as possibilities rather than actualities. In summary, although the ability to reason about mutually inconsistent possibilities develops slowly in the preschool years, the ability to imagine and share information about possibilities is evident among 2- and 3-year-olds. Nothing comparable has been observed in great apes. Young children's ability to entertain shared possibilities diverges from that of non-human primates well before any potential watershed at 4 years with respect to the understanding of mutually exclusive possibilities. This article is part of the theme issue 'Thinking about possibilities: mechanisms, ontogeny, functions and phylogeny'.

How children revise their beliefs in light of reasons

We investigate how the ability to respond appropriately to reasons provided in discourse develops in young children. In Study 1 (N = 58, Germany, 26 girls), 4- and 5-, but not 3-year-old children, differentiated good from bad reasons. In Study 2 (N = 131, Germany, 64 girls), 4- and 5-year-old children considered both the strength of evidence for their initial belief and the quality of socially provided reasons for an alternative view when deciding whether to change their minds. Study 3 (N = 80, the United States, 42 girls, preregistered) shows that 4- and 5-year-old children also consider meta-reasons (reasons about reasons) in their belief revision. These results suggest that by age 4, children possess key critical thinking capacities for participating in public discourse.

Plausibility matters: A challenge to Gilbert's "Spinozan" account of belief formation

Most of the claims we encounter in real life can be assigned some degree of plausibility, even if they are new to us. On Gilbert's (1991) influential account of belief formation, whereby understanding a sentence implies representing it as true, all new propositions are initially accepted, before any assessment of their veracity. As a result, plausibility cannot have any role in initial belief formation on this account. In order to isolate belief formation experimentally, Gilbert, Krull, and Malone (1990) employed a dual-task design: if a secondary task disrupts participants' evaluation of novel claims presented to them, then the initial encoding should be all there is, and if that initial encoding consistently renders claims 'true' (even where participants were told in the learning phase that the claims they had seen were false), then Gilbert's account is confirmed. In this pre-registered study, we replicate one of Gilbert et al.'s (1990) seminal studies ("The Hopi Language Experiment") while additionally introducing a plausibility variable. Our results show that Gilbert's 'truth bias' does not hold for implausible statements - instead, initial encoding seemingly renders implausible statements 'false'. As alternative explanations of this finding that would be compatible with Gilbert's account can be ruled out, it questions Gilbert's account.

Infants actively seek and transmit knowledge via communication

Supporting the central claim that knowledge representation is more basic than belief representation, we focus on the emerging evidence for preverbal infants' active and selective communication based on their representation of both knowledge and ignorance. We highlight infants' ontogenetically early deliberate information seeking and information transmission in the context of active social learning, arguing that these capacities are unique to humans.

Deriving Features of Religions in the Wild : How Communication and Threat-Detection May Predict Spirits, Gods, Witches, and Shamans

Religions "in the wild" are the varied set of religious activities that occurred before the emergence of organized religions with doctrines, or that persist at the margins of those organized traditions. These religious activities mostly focus on misfortune; on how to remedy specific cases of illness, accidents, failures; and on how to prevent them. I present a general model to account for the cross-cultural recurrence of these particular themes. The model is based on (independently established) features of human psychology-namely, (a) epistemic vigilance, the set of systems whereby we evaluate the quality of information and of sources of information, and (b) threat-detection psychology, the set of evolved systems geared at detecting potential danger in the environment. Given these two sets of systems, the dynamics of communication will favor particular types of messages about misfortune. This makes it possible to predict recurrent features of religious systems, such as the focus on nonphysical agents, the focus on particular cases rather than general aspects of misfortune, and the emergence of specialists. The model could illuminate not just why such representations are culturally successful, but also why people are motivated to formulate them in the first place.

Young children update their trust in an informant's claim when experience tells them otherwise

Across two experiments, an adult informant presented 220 preschoolers (34-71 months of age) with either a correct claim or an incorrect claim about how to activate a music box by using one of two toy figures. Children were then prompted to explore the figures and to discover whether the informant's claim was correct or incorrect. Children who discovered the claim to be incorrect no longer endorsed it. Moreover, their predictions regarding a new figure's ability to activate the music box were clearly affected by the reliability of the informant's prior claim. Thus, children reassess an informant's incorrect claim about an object in light of later empirical evidence and transfer their conclusions regarding the validity of that claim to subsequent objects.

Infants' Ability to Detect Emotional Incongruency: Deep or Shallow?

Infants can detect individuals who demonstrate emotions that are incongruent with an event and are less likely to trust them. However, the nature of the mechanisms underlying this selectivity is currently subject to controversy. The objective of this study was to examine whether infants' socio-cognitive and associative learning skills are linked to their selective trust. A total of 102 14-month-olds were exposed to a person who demonstrated congruent or incongruent emotional referencing (e.g., happy when looking inside an empty box), and were tested on their willingness to follow the emoter's gaze. Knowledge inference and associative learning tasks were also administered. It was hypothesized that infants would be less likely to trust the incongruent emoter and that this selectivity would be related to their associative learning skills, and not their socio-cognitive skills. The results revealed that infants were not only able to detect the incongruent emoter, but were subsequently less likely to follow her gaze toward an object invisible to them. More importantly, infants who demonstrated superior performance on the knowledge inference task, but not the associative learning task, were better able to detect the person's emotional incongruency. These findings provide additional support for the rich interpretation of infants' selective trust.

(Un)common knowledge: Children use social relationships to determine who knows what

Socially savvy individuals track what they know and what other people likely know, and they use this information to navigate the social world. We examine whether children expect people to have shared knowledge based on their social relationships (e.g., expecting friends to know each other's secrets, expecting members of the same cultural group to share cultural knowledge) and we compare children's reasoning about shared knowledge to their reasoning about common knowledge (e.g., the wrongness of moral violations). In three studies, we told 4- to 9-year-olds (N = 227) about what a child knew and asked who else knew the information: The child's friend (Studies 1-3), the child's schoolmate (Study 1), another child from the same national group (Study 2), or the child's sibling (Study 3). In all three studies, older children reliably used relationships to infer what other people knew. Moreover, with age, children increasingly considered both the type of knowledge and an individual's social relationships when reporting who knew what. The results provide support for a 'Selective Inferences' hypothesis and suggest that children's early attention to social relationships facilitates an understanding of how knowledge transfers - an otherwise challenging cognitive process.

Obstacles to the spread of unintuitive beliefs

Many socially significant beliefs are unintuitive, from the harmlessness of GMOs to the efficacy of vaccination, and they are acquired via deference toward individuals who are more confident, more competent or a majority. In the two-step flow model of communication, a first group of individuals acquires some beliefs through deference and then spreads these beliefs more broadly. Ideally, these individuals should be able to explain why they deferred to a given source - to provide arguments from expertise - and others should find these arguments convincing. We test these requirements using a perceptual task with participants from the US and Japan. In Experiment 1, participants were provided with first-hand evidence that they should defer to an expert, leading a majority of participants to adopt the expert's answer. However, when attempting to pass on this answer, only a minority of those participants used arguments from expertise. In Experiment 2, participants receive an argument from expertise describing the expert's competence, instead of witnessing it first-hand. This leads to a significant drop in deference compared with Experiment 1. These experiments highlight significant obstacles to the transmission of unintuitive beliefs.

Does intention matter? Relations between parent pointing, infant pointing, and developing language ability

Infants' pointing is associated with concurrent and later language development. The communicative intention behind the point-i.e., imperative versus declarative-can affect both the nature and strength of these associations, and is therefore a critical factor to consider. Parents' pointing is associated with both infant pointing and infant language; however, less work has examined the intent behind parents' points. We explore relations between parents' and infants' pointing at the level of communicative intention, and examine how pointing relates to concurrent and longitudinal infant language skills. In a sample of 52 mother-infant dyads, we measured mother and infant pointing at infant age 12-months, and infant expressive and receptive language at 12-, 18-, and 24-months. We found that mothers produced points with a variety of intentions, however we did not find relations between mother and infant pointing within the different communicative intentions. Replicating previous research, infant declarative pointing was related both concurrently and longitudinally to their language ability. Mothers' declarative pointing was related to their infants' concurrent language, while their imperative pointing was not. Further, there was an interaction between parent and infant declarative pointing, such that the positive relation between parents' declarative pointing and their infants' concurrent receptive language was present only for those infants who were also producing declarative points themselves. Findings suggest that parents' declarative pointing may support both their infants' early word learning and, perhaps, provides a model for their infant to begin using points as well. This study constitutes an important initial exploration of these relations.

Majority rules: how good are we at aggregating convergent opinions?

Mathematical models and simulations demonstrate the power of majority rules, i.e. following an opinion shared by a majority of group members. Majority opinion should be followed more when (a) the relative and absolute size of the majority grow, the members of the majority are (b) competent, and (c) benevolent, (d) the majority opinion conflicts less with our prior beliefs and (e) the members of the majority formed their opinions independently. We review the experimental literature bearing on these points. The few experiments bearing on (b) and (c) suggest that both factors are adequately taken into account. Many experiments show that (d) is also followed, with participants usually putting too much weight on their own opinion relative to that of the majority. Regarding factors (a) and (e), in contrast, the evidence is mixed: participants sometimes take into account optimally the absolute and relative size of the majority, as well as the presence of informational dependencies. In other circumstances, these factors are ignored. We suggest that an evolutionary framework can help make sense of these conflicting results by distinguishing between evolutionarily valid cues - that are readily taken into account - and non-evolutionarily valid cues - that are ignored by default.

Fourteen-month-olds selectively search for and use information depending on the familiarity of the informant in both laboratory and home contexts

Infants are selective in their learning from others. However, there is only very limited research on the possible factors that shape this selectivity, especially when it comes to the impact of infants' familiarity with the informant and the context. The current study investigated whether 14-month-olds preferred to receive and use information provided by an unfamiliar informant (experimenter) compared with a familiar informant (parent) and whether this pattern depended on the context (home vs. laboratory). We tested infants either in the laboratory (n = 67) or in their home (n = 70). When both informants presented a novel object with positive or negative emotions, we measured infants' gaze behavior as an indicator for information search. When infants acted on the novel object themselves, we measured their exploratory behavior as an indicator of information use. Results revealed no effect of context on infants' information search and use. Rather, we found that the familiarity of informant had distinct effects on infant attention and object exploration. Namely, infants looked longer at the unfamiliar informant across contexts, but they explored more when the familiar informant presented the object compared with when the unfamiliar informant did so. Thus, during information search, 14-month-olds paid most attention to an unfamiliar source of information. However, participants explored the objects more when they came from a familiar source than when they came from an unfamiliar one. Possible explanations for these findings are discussed.

Willingness to revise own testimony: 3- and 4-year-olds' selective trust in unexpected testimony from accurate and inaccurate informants

Prior work has shown that young children trust single accurate and inaccurate individuals to a similar extent in their endorsement of novel information. However, it remains unknown to what extent children trust a credible or noncredible individual when given information that is pitted against their own beliefs. The current study examined whether children, when given unexpected testimony that contradicted their initial beliefs but was not completely unbelievable, would selectively revise their beliefs depending on the informant's past history of accuracy. The participants (3- and 4-year-olds; N = 100) were familiarized with an informant who labeled a series of common objects either accurately or inaccurately. Following that, all children saw a picture of an ambiguous hybrid artifact that consisted of features of two typical common artifacts and were asked to identify the hybrid object with their own label. Subsequently, children watched the previously accurate or inaccurate informant give the same hybrid object a different but plausible label. Children expressed a greater tendency to override their initial judgments and endorse the unexpected testimony from a previously accurate informant than from someone who had consistently made naming errors. The findings provide novel understandings of the circumstances under which 3- and 4-year-old preschoolers may or may not rely on the informant's prior reliability in their selective learning.

Two-year-olds use adults' but not peers' points

In the current study, 24- to 27-month-old children (N = 37) used pointing gestures in a cooperative object choice task with either peer or adult partners. When indicating the location of a hidden toy, children pointed equally accurately for adult and peer partners but more often for adult partners. When choosing from one of three hiding places, children used adults' pointing to find a hidden toy significantly more often than they used peers'. In interaction with peers, children's choice behavior was at chance level. These results suggest that toddlers ascribe informative value to adults' but not peers' pointing gestures, and highlight the role of children's social expectations in their communicative development.

Children's Developing Ideas About Knowledge and Its Acquisition

We review key aspects of young children's concept of knowledge. First, we discuss children's early insights into the way that information can be communicated from informant to recipient as well as their active search for information via questions. We then analyze the way that preschool children talk explicitly and cogently about knowledge and the presuppositions they make in doing so. We argue that all children, irrespective of culture and language, eventually arrive at the same fundamental conception of knowledge in the preschool years. Nevertheless, despite the universality of this basic conception, young children are likely to show considerable variation in their pattern of information seeking, depending on the conversational practices of their family and culture.

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.

How Gullible are We? A Review of the Evidence from Psychology and Social Science

A long tradition of scholarship, from ancient Greece to Marxism or some contemporary social psychology, portrays humans as strongly gullible—wont to accept harmful messages by being unduly deferent. However, if humans are reasonably well adapted, they should not be strongly gullible: they should be vigilant toward communicated information. Evidence from experimental psychology reveals that humans are equipped with well-functioning mechanisms of epistemic vigilance. They check the plausibility of messages against their background beliefs, calibrate their trust as a function of the source's competence and benevolence, and critically evaluate arguments offered to them. Even if humans are equipped with well-functioning mechanisms of epistemic vigilance, an adaptive lag might render them gullible in the face of new challenges, from clever marketing to omnipresent propaganda. I review evidence from different cultural domains often taken as proof of strong gullibility: religion, demagoguery, propaganda, political campaigns, advertising, erroneous medical beliefs, and rumors. Converging evidence reveals that communication is much less influential than often believed—that religious proselytizing, propaganda, advertising, and so forth are generally not very effective at changing people's minds. Beliefs that lead to costly behavior are even less likely to be accepted. Finally, it is also argued that most cases of acceptance of misguided communicated information do not stem from undue deference, but from a fit between the communicated information and the audience's preexisting beliefs.

The Development of Selective Copying: Children's Learning From an Expert Versus Their Mother

This study tested the prediction that, with age, children should rely less on familiarity and more on expertise in their selective social learning. Experiment 1 (N = 50) found that 5- to 6-year-olds copied the technique their mother used to extract a prize from a novel puzzle box, in preference to both a stranger and an established expert. This bias occurred despite children acknowledging the expert model's superior capability. Experiment 2 (N = 50) demonstrated a shift in 7- to 8-year-olds toward copying the expert. Children aged 9-10 years did not copy according to a model bias. The findings of a follow-up study (N = 30) confirmed that, instead, they prioritized their own-partially flawed-causal understanding of the puzzle box.

Young Children Treat Robots as Informants

Children ranging from 3 to 5 years were introduced to two anthropomorphic robots that provided them with information about unfamiliar animals. Children treated the robots as interlocutors. They supplied information to the robots and retained what the robots told them. Children also treated the robots as informants from whom they could seek information. Consistent with studies of children's early sensitivity to an interlocutor's non-verbal signals, children were especially attentive and receptive to whichever robot displayed the greater non-verbal contingency. Such selective information seeking is consistent with recent findings showing that although young children learn from others, they are selective with respect to the informants that they question or endorse.

The Developmental Origins of Selective Social Learning

The study of children's social learning is a topic of central importance to our understanding of human development. Learning from others allows children to acquire information efficiently; however, not all information conveyed by others is accurate or worth learning. A large body of research conducted over the past decade has shown that preschoolers learn selectively from some individuals over others. In the present article we summarize our work and that of others on the developmental origins of selective social learning during infancy. The results of these studies indicate that infants are sensitive to a number of cues, including competence, age, and confidence, when deciding from whom to learn. We highlight the important implications of this research in improving our understanding of the cognitive and social skills necessary for selective learning, and point out promising avenues for future research.

The active role played by human learners is key to understanding the efficacy of teaching in humans

The early developing capacity of human learners to seek out reliable informants, initiate pedagogical episodes, and monitor and redirect ongoing instruction is critical to understanding humans' remarkable capacity for cumulative culture.

Infants track the reliability of potential informants

Across two eye-tracking experiments, we showed that infants are sensitive to the statistical reliability of informative cues and selective in their use of information generated by such cues. We familiarized 8-month-olds with faces (Experiment 1) or arrows (Experiment 2) that cued the locations of animated animals with different degrees of reliability. The reliable cue always cued a box containing an animation, whereas the unreliable cue cued a box that contained an animation only 25% of the time. At test, infants searched longer in the boxes that were reliably cued, but did not search longer in the boxes that were unreliably cued. At generalization, when boxes were cued that never contained animations before, only infants in the face experiment followed the reliable cue. These results provide the first evidence that even young infants can track the reliability of potential informants and use this information judiciously to modify their future behavior.