The Early Ontogeny of Reason Giving

Turkish- and English-speaking 3-year-old children are sensitive to the evidential strength of claims when revising their beliefs

Individuals revise their beliefs based on the evidential strength of others' claims. Unlike English, in languages such as Turkish evidential marking is obligatory; speakers must express whether their claims are based on direct observation or not. We investigated whether Turkish- and English-speaking 3- and 5-year-olds (N = 146; 72 girls; based in Turkey and Canada) differed in their belief revision after hearing claims based on direct observation, indirect observation, or inference. We found the same pattern in both linguistic groups; the 3-year-olds revised their beliefs more often when they heard claims based on direct observation and inference than on indirect observation, whereas the 5-year-olds showed no difference across different claims. By age 3, Turkish- and English-speaking children are sensitive to the strength of claims when revising their beliefs.

Disagreement reduces overconfidence and prompts exploration in young children

Can the experience of disagreement lead young children to reason in more sophisticated ways? Across two preregistered studies, four- to six-year-old US children (N = 136, 50% female, mixed ethnicities, data collected 2020-2022) experienced either a disagreement or an agreement with a confederate about a causal mechanism after being presented with ambiguous evidence. We measured (1) children's confidence in their belief before and after the (dis)agreement, and (2) how long children searched for information about the correct answer. Disagreement, especially with an expert (Experiment 2), reduced overconfidence and prompted children to search longer for information, compared to agreement. Together, our findings suggest possibilities for interventions aimed at fostering humility and learning across the lifespan.

A cross-linguistic approach to children's reasoning: Turkish- and English-speaking children's use of metatalk

When collaboratively solving problems, children discuss information reliability, for example, whether claims are based on direct or indirect observation, termed as "metatalk". Unlike English in which evidential marking is optional, languages with obligatory evidential marking such as Turkish, might provide children some advantages in communicating the reliability of their claims. The current preregistered online study investigated Turkish- and English-speaking 3- and 5-year-old children's (N = 144) use of metatalk. The child and the experimenter (E) were asked to decide in which of the two houses a toy was hiding. One house had the toy's footprints. When E left the Zoom meeting, an informant told the child that the toy was in the other house without the footprints in three within-subjects conditions. In the direct-observation condition, the child witnessed the informant move the toy. In the indirect-witness condition, the informant checked both houses and said that the toy was in the other house. In the indirect-hearsay condition, the informant simply said that the toy was in the other house. When E returned, the child had to convince E about how they knew the toy was in the other house using metatalk (e.g., "I saw it move"). Turkish-speaking children used metatalk more often than did English-speaking children, especially in the direct-observation condition. In the two indirect conditions, both groups of 5-year-olds were similar in their use of metatalk, but Turkish speaking 3-year-olds produced metatalk more often than did English-speaking 3-year-olds. Thus, languages with obligatory evidential marking might facilitate children's collaborative reasoning. RESEARCH HIGHLIGHTS: Children as young as 3 years of age can produce metatalk. Turkish-speaking children produce metatalk more often than English-speaking children. The difference between the two linguistic groups is more pronounced at age 3.

Should I stay or should I go? Three-year-olds' reactions to appropriate motives to interrupt a joint activity

Understanding when it is acceptable to interrupt a joint activity is an important part of understanding what cooperation entails. Philosophical analyses have suggested that we should release our partner from a joint activity anytime the activity conflicts with fulfilling a moral obligation. To probe young children's understanding of this aspect, we investigated whether 3-year-old children (N = 60) are sensitive to the legitimacy of motives (selfish condition vs. moral condition) leading agents to intentionally interrupt their joint activity. We measured whether children protested or released their partner by scoring their reactions. Our results indicate that children did not manifest different reactions when the motive behind their partner leaving was moral than when the motive was selfish. However, our data showed a stable pattern: regardless of the partner's motives, some 3-year-olds take initiatives to release their partners from joint activity, suggesting that measuring release is a valuable tool for investigating joint action.

Five-year-old children value reasons in apologies for belief-based accidents

Accidents can be intent-based (unintended action-unintended outcome) or belief-based (intended action-unintended outcome). As compared to intent-based accidents, giving reasons is more crucial for belief-based accidents because the transgressor appears to have intentionally transgressed. In Study 1, UK-based preschoolers who were native English speakers (N = 96, 53 girls, collected 2020-2021) witnessed two intent-based or belief-based accidents; one transgressor apologized, the other apologized with a reason. Five-year-olds, but not 4-year-olds, favored the reason-giving transgressor following a belief-based accident but not an intent-based accident (where an apology sufficed). In Study 2, 5-year-olds (N = 48, 25 girls, collected 2021) distinguished between "good" and "bad" reasons for the harm caused. Thus, 5-year-old children recognize when reasons should accompany apologies and account for the quality of these reasons.

Children's developing ability to adjust their beliefs reasonably in light of disagreement

Two preregistered experiments (N = 218) investigated children's developing ability to respond reasonably to disagreement. U.S. children aged 4-9, and adults (50% female, mostly white) formed an initial belief, and were confronted with the belief of a disagreeing other, whose evidence was weaker, stronger than, or equal to participants' evidence. With age, participants were increasingly likely to maintain their initial belief when their own evidence was stronger, adopt the other's belief when their evidence was weaker, and suspend judgment when both had equally strong evidence. Interestingly, 4- to 6-year-olds only suspended judgment reliably when this was assessed via the search for additional information (Experiment 2). Together, our experiments suggest that the ability to respond reasonably to disagreement develops over the preschool years.

Disagreement, justification, and equitable moral judgments: A brief training study

Although theorists agree that social interactions play a major role in moral development, previous research has not experimentally assessed how specific features of social interactions affect children's moral judgments and reasoning. The current study assessed two features: disagreement and justification. In a brief training phase, children aged 4-5.5 years (N = 129) discussed simple moral scenarios about issues of fairness (how to allocate things between individuals) with a puppet who, in a between-participants factorial design, either agreed or disagreed with the children's ideas and either asked or did not ask the children to justify their ideas. Children then responded to another set of moral scenarios in a test phase that was the same for all children. Children in the "agree and do not justify" baseline condition showed an inflexible equality bias (preferring only equal allocations regardless of context), but children who had experiences of disagreement or experiences of being asked to justify themselves shifted toward making equitable decisions based on common ground norms and values. Furthermore, false belief competence was related to children's decisions and justifications. These findings support the classic Piagetian hypothesis that social interactions are a catalyst of cognitive disequilibrium and moral development.

A New Look at Young Children's Referential Informativeness

In this article, I review experimental evidence for the dependence of 2- to 5-year-olds' linguistic referential informativeness on cues to common ground (CG) and propose a process model. Cues to CG provide evidence for CG, that is, for the shared knowledge, beliefs, and attitudes of interlocutors. The presence of cues to CG (e.g., unimpeded listener line of regard or prior mention) is shown to be associated with less informative reference (e.g., pronouns). In contrast, the absence of cues to CG (e.g., impeded listener line of regard or new mention) is shown to be associated with more informative reference (e.g., nouns). Informativeness is sensitive to linguistic before nonlinguistic cues to CG (i.e., 2.0 vs. 2.5 years old, respectively). Reference is cast as a process of active inference, a formulation of Bayesian belief-guided control in biological systems. Child speakers are hierarchical generative models that, characteristically, expect sensory evidence for the evolved, prior Bayesian belief that interlocutor mental states are aligned (i.e., that CG exists). Referential control emerges as an embodied tool to gather evidence for this prior belief. Bottom-up cues to CG elicited by action drive updates to beliefs about CG. In turn, beliefs about CG guide efficient referential control.

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.

Preschool children's use of meta-talk to make rational collaborative decisions

In collaborative decision-making, partners compare reasons behind conflicting proposals through meta-talk. We investigated UK-based preschoolers' (mixed socioeconomic status) use of meta-talk (Data collection: 2018-2020). In Study 1, 5- and 7-year-old peer dyads (N = 128, 61 girls) heard conflicting claims about an animal from two informants. One prefaced her claim with "I know"; the other with "I think". Dyads identified the more reliable informant through meta-talk ("She said she knows"). In Study 2, 3- and 5-year-olds (N = 64, 34 girls) searched for a toy with an adult partner making incorrect proposals. Children refuted this through reporting what they had witnessed (It cannot be there because "I saw it move", "she moved it"). In preschool period, children start using meta-talk to make rational collaborative decisions.

Preschoolers learn new moral and conventional norms from direct experiences

By observing others, children can learn about different types of norms, including moral norms rooted in concerns for welfare and rights, and social conventions based on directives from authority figures or social consensus. Two experiments examined how preschoolers and adults constructed and applied knowledge about novel moral and conventional norms from their direct social experiences. Participants watched a video of a novel prohibited action that caused pain to a victim (moral conditions) or a sound from a box (conventional conditions). Next, they saw a transgressor puppet, who had either watched the video alongside participants or not, engage in the prohibited action. Preschoolers and adults rapidly constructed distinct moral and conventional evaluations about the novel actions. These distinctions were evident across several response modalities that have often been studied separately, including judgments, reasoning, and actions. However, children did not reliably track the puppet's knowledge of the novel norms. These studies provide experimental support for the idea that children and adults construct distinct moral and conventional norms from social experiences, which in turn guide judgments, reasoning, and behavior.