How do young children decide to trust testimony thatcontradicts their initial beliefs? The current study examinedwhether children rely on cues to informant credibility (i.e.,history of accuracy) to determine if they would endorse anunexpected label from an informant. Three- and 4-year-olds(N = 60) saw a picture of a hybrid artifact that consisted offeatures of two typical familiar artifacts. Children made initialjudgments about the name of the hybrid object andsubsequently received a different name offered by aninformant who had earlier either accurately or inaccuratelynamed familiar objects. Children were more willing to revisetheir own judgment and accept the unexpected label if it wasfrom a previously accurate informant than if it was fromsomeone who had made obvious naming errors. This suggeststhat preschool-aged children selectively revise their ownknowledge; they are more trusting toward sources provenaccurate than inaccurate.

The ability to understand and speak more than one language (i.e., bilingualism) may offer some protection against age-related cognitive deterioration. Although research on children and young adults has reported that bilinguals outperform monolinguals in some theory-of-mind (ToM) tasks, a similar positive effect of bilingualism on older adults’ ToM has yet to be established. Here, we examined the effects of bilingual experience (i.e., onset age of bilingualism) on ToM in normal aging using the ToM Task Battery with 60 young adults (aged 18-30) and 72 older adults (aged 56-79). Results revealed that older adults showed deficits in ToM and their performance gradually declined with age compared to young adults. Importantly, early bilingualism mediated the age differences in ToM; earlier onset age of bilingualism predicted better ToM performance in older adulthood. Findings suggest a possible protective effect of early bilingualism against age-related declines in socio-cognitive functions.

Others’ beliefs about the self can powerfully influence our everyday interactions with others. Recent work suggests that even preschool-aged children are sensitive to what others think of the self and actively attempt to manage these beliefs (Asaba & Gweon, 2018). What cognitive capacities underlie these early self-presentational behaviors, and in what contexts do these behaviors emerge? Here we show that preschoolers strategically demonstrate their competence to even a puppet, but only when an adult treats the puppet as an agent and specifically asks which toy the child wants to “show” to the puppet (Exp.1). However, they do not show such strategic demonstration of their competence when the same puppet is treated as an object (Exp.2). These results suggest that self- presentational behaviors can emerge even in the absence of any immediate prospect of social evaluation insofar as children consider the target entity as capable of holding beliefs. Furthermore, whether or not children ascribe a belief about the self to the target is heavily modulated by how an entity is treated by others. We discuss the relevance of these findings to early reputation management behaviors, and more broadly, the use of make-believe agents in developmental research.

Bilinguals’ need to monitor and inhibit non-relevantlanguages over a relevant one confers advantage in cognitivecontrol. No studies have demonstrated that the dual-languagecontrol process directly contributes to the bilingual cognitiveadvantage. We utilized a novel language control manipulationparadigm where 83 English-Chinese bilingual adultscompleted a reading and comprehension task in either single-language (low-language-control) or dual-language (high-language-control) prior to performing nonverbal executivecontrol tasks (Stroop, task-switching, and n-back). Resultsshowed that language control had significant effects onsubsequent cognitive performance, depending on whether theparticipants were regular dual language users or not. In thedual-language condition, but not the single-languagecondition, participants who used both languages regularlydemonstrated a smaller mixing cost in task-switching and agreater sensitivity in n-back detection compared toparticipants who did not. This suggests that dual languagecontrol utilizes similar resources as executive function andfrequent dual language use enhances this resource.