Rattling the developmental psychologist's cage?

Infants' selective imitation of a transitive agent and an intransitive agent

This study examined how the reliability (i.e., transitivity) of an agent's object choices affects 16-month-old infants' (N = 48) imitation of her unconventional way of turning on a touch light box with her head when her hands were available. When the agent made transitive choices (i.e., she chose Object A over Object B, Object B over Object C, and then A over C), infants imitated her head touch actions. When the agent made intransitive choices (i.e., after choosing A over B and B over C, she chose C over A), infants were more likely to use only their hands to touch the light box. In addition, when it was presumably difficult for infants to judge the transitivity of the agent's choices (i.e., she chose B over C, A over B, and then A over C), they used their hands more. These results demonstrate that infants' understanding informs their decisions to selectively imitate others' specific ways to act on novel artifacts, consistent with young children's selective trust in information provided by other people based on their epistemic reliability.

Specifying links between infants' theory of mind, associative learning, and selective trust

The psychological mechanisms underlying infants' selective social learning are currently a subject of controversy. The main goal of the present study was to contribute data to this debate by investigating whether domain-specific or domain-general abilities guide infants' selectivity. Eighteen-month-olds observed a reliable and an unreliable speaker, and then completed a forced-choice word learning paradigm, two theory of mind tasks, and an associative learning task. Results revealed that infants showed sensitivity to the verbal competence of the speaker. Additionally, infants with superior knowledge inference abilities were less likely to learn from the unreliable speaker. No link was observed between selective social learning and associative learning skills. These results replicate and extend previous findings demonstrating that socio-cognitive abilities are linked to infants' selective social learning.

Theory of mind development: State of the science and future directions

This chapter offers a brief overview of how research on theory of mind development has developed over the recent years, with a focus on current research and theoretical accounts of theory of mind during the infancy period. The topics covered include the factors contributing to individual differences in theory of mind skills in preschoolers, the current replication crisis in theory of mind in infancy, the stability of theory of mind from infancy to childhood, and recent research suggesting that infants' concept of false belief is, at best, immature (e.g., overattribution to inanimate agents). Future directions in theory of mind research are suggested.

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.

Knowing who knows: Metacognitive and causal learning abilities guide infants' selective social learning

Given the widespread interest in the development of children's selective social learning, there is mounting evidence suggesting that infants prefer to learn from competent informants (Poulin-Dubois & Brosseau-Liard, Current Directions in Psychological Science, 2016, 25). However, little research has been dedicated to understanding how this selectivity develops. The present study investigated whether causal learning and precursor metacognitive abilities govern discriminant learning in a classic word-learning paradigm. Infants were exposed to a speaker who accurately (reliable condition) or inaccurately (unreliable condition) labeled familiar objects and were subsequently tested on their ability to learn a novel word from the informant. The predictive power of causal learning skills and precursor metacognition (as measured through decision confidence) on infants' word learning was examined across both reliable and unreliable conditions. Results suggest that infants are more inclined to accept an unreliable speaker's testimony on a word learning task when they also lack confidence in their own knowledge on a task measuring their metacognitive ability. Additionally, when uncertain, infants draw on causal learning abilities to better learn the association between a label and a novel toy. This study is the first to shed light on the role of causal learning and precursor metacognitive judgments in infants' abilities to engage in selective trust.

Selective social learning in infancy: looking for mechanisms

Although there is mounting evidence that selective social learning begins in infancy, the psychological mechanisms underlying this ability are currently a controversial issue. The purpose of this study is to investigate whether theory of mind abilities and statistical learning skills are related to infants' selective social learning. Seventy-seven 18-month-olds were first exposed to a reliable or an unreliable speaker and then completed a word learning task, two theory of mind tasks, and a statistical learning task. If domain-general abilities are linked to selective social learning, then infants who demonstrate superior performance on the statistical learning task should perform better on the selective learning task, that is, should be less likely to learn words from an unreliable speaker. Alternatively, if domain-specific abilities are involved, then superior performance on theory of mind tasks should be related to selective learning performance. Findings revealed that, as expected, infants were more likely to learn a novel word from a reliable speaker. Importantly, infants who passed a theory of mind task assessing knowledge attribution were significantly less likely to learn a novel word from an unreliable speaker compared to infants who failed this task. No such effect was observed for the other tasks. These results suggest that infants who possess superior social-cognitive abilities are more apt to reject an unreliable speaker as informant. A video abstract of this article can be viewed at: https://youtu.be/zuuCniHYzqo.