Exploring the use of projected videos to test action matching from different perspectives in dogs

Dogs trained with the Do as I Do method can imitate human actions upon request, but their ability to match actions observed from different perspectives remains unknown. The use of 2D video stimuli may enable researchers to systematically manipulate the perspective from which demonstrations are observed, thereby widening the range of methods available to study cognitive skills related to imitation. In this study, we explore the possibility of using 2D stimuli to test action matching in dogs, including when demonstrations are seen from different perspectives. We examined two dogs' imitative performance using videos projected on a screen; while, the owner interacted with the dog remotely through an online meeting software. The dogs were first trained to match human actions seen on a screen frontally, and then were tested when the projected demonstrations were seen frontally, from the side, and from above. Results revealed that both dogs matched the demonstrated actions from frontal and, notably, also from side perspectives, at least to some extent, consistent with familiarity of their daily interactions with humans. However, action matching from an above perspective presented challenges, indicating the potential influence of observational experience and highlighting the importance of perspective manipulation when investigating imitation abilities. These findings show that it is possible to use 2D videos to test imitation in dogs, thereby expanding the potential methodologies to study imitation and other related cognitive skills.

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.

When does selection favor learning from the old? Social learning in age-structured populations

Culture and demography jointly facilitate flexible human adaptation, yet it still remains unclear how social learning operates in populations with age structure. Here, we present a mathematical model of the evolution of social learning in a population with different age classes. We investigate how demographic processes affect the adaptive value of culture, cultural adaptation and population growth, and identify the conditions that favor learning from older vs. younger individuals. We find that, even with age structure, social learning can evolve without increasing population fitness, i.e., “Rogers’ paradox” still holds. However, a process of “demographic filtering”, together with cultural transmission, can generate cumulative improvements in adaptation levels. We further show that older age classes have higher proportions of adaptive behavior when the environment is stable and adaptive behavior is hard to acquire but important to survival. Through individual-based simulations comparing temporal and spatial variability in the environment, we find a “copy-the-old”-strategy only evolves when social learning is erroneous and the opposite “copy-the-young”-strategy can function as a compromise between individual and social information use. Our results reveal that age structure substantially changes how culture evolves and provide principled empirical expectations about age-biased social learning and the role of demography in cultural adaptation.

Toddlers Prefer Adults as Informants: 2- and 3-Year-Olds' Use of and Attention to Pointing Gestures From Peer and Adult Partners

Two- and 3-year-old children (N = 96) were tested in an object-choice task with video presentations of peer and adult partners. An immersive, semi-interactive procedure enabled both the close matching of adult and peer conditions and the combination of participants' choice behavior with looking time measures. Children were more likely to use information provided by adults. As the effect was more pronounced in the younger age-group, the observed bias may fade during toddlerhood. As there were no differences in children's propensity to follow peer and adult gestures with their gaze, these findings provide some of the earliest evidence to date that young children take an interlocutor's age into account when judging ostensively communicated testimony.

Toddlers’ peer engagement in Swiss childcare: contribution of individual and contextual characteristics

The present study observed 86 three-year-old children (M = 43.7, SD = 6.4) from 15 Swiss childcare groups, to investigate multiple individual and contextual contributions to toddlers’ positive engagement with peers. The children’s individual characteristics (age, sex and social skills) and childcare-related predictors (emotional and behavioural support from caregivers, and structural group features) were assessed. We employed the child-by-environment perspective and tested the hypothesis that high-quality behavioural and emotional support provided by caregivers benefits children with deficits in social abilities. Results of the multilevel structural equation modelling indicated that toddlers rated by caregivers as sociable and assertive showed more positive situation-specific peer engagement, especially with a concomitant higher quality of caregiver emotional and behavioural support. By contrast, being prosocial-cooperative was negatively associated with observed peer engagement. Thus, children’s social skills were found to be the most important factor for peer engagement in childcare settings. Important suggestions for future research are made, and practical implications are discussed.

The effect of napping and nighttime sleep on memory in infants

During the first year of life, infants devote the majority of their time to sleep. Research in adults has shown that sleep supports a variety of memory processes. Surprisingly, sleep's function for infant memory has only started to receive attention in research. In this chapter, we will describe age-related changes in sleep and in memory processing over the first years of life, as well as methods to capture both sleep and memory. Then, we will review current findings on the effects of sleep on memory processing in infants. Lastly, we will also point out gaps in current knowledge and describe potential avenues for future research. Overall, the results of recent experimental studies provide evidence that timely, extended napping is involved in how memories are encoded and stored in the long-term and contribute to the formation of knowledge networks in infants.

Trust in early childhood

Children need to build trust in their primary caregivers or significant others, as well as people who are unrelated to them, including those who belong to different social groups. The present chapter focuses on children's trust in unfamiliar individuals. How do they determine who to trust? Does putting trust in another person operate differently depending on the specific issue at hand? To address these questions, we differentiate between two forms of trust: children's trust in others' epistemic states to learn from others (epistemic trust) and trusting others for social support and reassurance (social trust), for example, when to expect that interaction partners will be truthful and keep promises. We first review the literature on epistemic trust to show that young children seem to value others' accuracy and competence when learning from them, even when these individuals are from different linguistic or racial groups than their own. We then present findings on social trust suggesting that young children trust those who are well-meaning and who keep their promises. Finally, we raise the question of whether there are environmental influences on the interaction of both epistemic and social trust with intergroup factors such as race, and we propose that research with infants will be useful to better illuminate the developmental roots of human trust.

Sensitivity to linguistic register in 20-month-olds: Understanding the register-listener relationship and its abstract rules

Linguistic register reflects changes in speech that depend on the situation, especially the status of listeners and listener-speaker relationships. Following the sociolinguistic rules of register is essential in establishing and maintaining social interactions. Recent research suggests that children over 3 years of age can understand appropriate register-listener relationships as well as the fact that people change register depending on their listeners. However, given previous findings that infants under 2 years of age have already formed both social and speech categories, it may be possible that even younger children can also understand appropriate register-listener relationships. The present study used Infant-Directed Speech (IDS) and formal Adult-Directed Speech (ADS) to examine whether 20-month-old toddlers can understand register-listener relationships. In Experiment 1, we used a violation-of-expectation method to examine whether 20-month-olds understand the individual associations between linguistic registers and listeners. Results showed that the toddlers looked significantly longer at a scene in which the adult was talked to in IDS than when the infant was talked to in IDS. In contrast, there was no difference when the adult and the infant were talked to in formal ADS. In Experiments 2 and 3, we used a habituation switch paradigm to examine whether 20-month-olds understand the abstract rule that a change of register depends on listeners rather than on speakers. Results showed that the toddlers looked significantly longer at the scene where the register rule was violated. The present findings provide new evidence that even 20-month-olds already understand that people change their way of speaking based on listeners, although their understanding of individual register-listener relationships is immature.

"Should I or shouldn't I?" Imitation of undesired versus allowed actions from peer and adult models by 18- and 24-month-old toddlers

Imitation is a common way of acquiring novel behaviors in toddlers. However, little is known about toddlers' imitation of undesired actions. Here we investigated 18- and 24-month-olds' (N=110) imitation of undesired and allowed actions from televised peer and adult models. Permissiveness of the demonstrated actions was indicated by the experimenter's response to their execution (angry or neutral). Analyses revealed that toddlers' imitation scores were higher after demonstrations of allowed versus undesired actions, regardless of the age of the model. In agreement with prior research, these results suggest that third-party reactions to a model's actions can be a powerful cue for toddlers to engage in or refrain from imitation. In the context of the present study, third-party reactions were more influential on imitation than the model's age. Considering the relative influence of different social cues for imitation can help to gain a fuller understanding of early observational learning.

When does social learning become cultural learning?

Developmental research on selective social learning, or 'social learning strategies', is currently a rich source of information about when children copy behaviour, and who they prefer to copy. It also has the potential to tell us when and how human social learning becomes cultural learning; i.e. mediated by psychological mechanisms that are specialized, genetically or culturally, to promote cultural inheritance. However, this review article argues that, to realize its potential, research on the development of selective social learning needs more clearly to distinguish functional from mechanistic explanation; to achieve integration with research on attention and learning in adult humans and 'dumb' animals; and to recognize that psychological mechanisms can be specialized, not only by genetic evolution, but also by associative learning and cultural evolution.

Deferred imitation in 9-month-olds

Studies investigating imitation are usually conducted with adult models in Western contexts; therefore, the influence of cultural context and the model’s age on infants' imitation is largely unknown. This study assessed deferred imitation in 9-month-old infants from the German middle-class ( N = 44) and the ethnic group of Nso in rural Cameroon ( N = 43). Infants either received an adult or an older child as a model. Moreover, the test material comprised varying degrees of target action difficulty. Across cultures and target actions infants imitated more when an adult model demonstrated the target actions. However, results revealed that infants did not show an adult model advantage for easier target actions, but only for those that were considered more difficult.

The relation between mirror self-image reactions and imitation in 14- and 18-month-old infants

Previous research suggests that sensitivity to aspects of the self and others develop in tandem. We tested 14- and 18-month-olds' imitative abilities and mirror self-image reactions (i.e., testing behavior and passing the mark test). Results showed that 14-month-olds' imitation was closely related to the occurrence of testing behavior in front of the mirror, where they checked whether they could control the movements of the mirror image. Eighteen-month-olds, however, no longer showed this relation. Furthermore, in 18-month-olds, we found a high association between imitation and passing the mark test. These correlations suggest that infants' mirror self-image reactions and imitation share the ability to detect and produce visual-motor contingencies.

Selective imitation of in-group over out-group members in 14-month-old infants

Recent research has shown that infants are more likely to engage with in-group over out-group members. However, it is not known whether infants' learning is influenced by a model's group membership. This study investigated whether 14-month-olds (N = 66) selectively imitate and adopt the preferences of in-group versus out-group members. Infants watched an adult tell a story either in their native language (in-group) or a foreign language (out-group). The adult then demonstrated a novel action (imitation task) and chose 1 of 2 objects (preference task). Infants did not show selectivity in the preference task, but they imitated the in-group model more faithfully than the out-group model. This suggests that cultural learning is beginning to be truly cultural by 14 months of age.

Re-enactment of intended acts from a video presentation by 18- and 24-month-old children

We used the Re-enactment of intention paradigm to investigate whether children would re-enact what an adult intended to do in a video presentation as they do when presented with a live demonstration (Meltzoff in Dev Psychol 31(5):838-850, 1995). Unlike the 18-month-old infants studied by Meltzoff (Dev Psychol 31(5):838-850, 1995), the 18- and 24-month-olds in the current study did not frequently imitate unsuccessful goal-directed actions presented in a video model. Children who performed better in the task also tended to share more of their attention with the experimenter during co-viewing of the video. Performance on the Re-enactment of intention task was positively related to categorization score, an independent measure of cognitive functioning.

Infant pointing serves an interrogative function

In recent years there has been a resurgence of interest in the motivations behind, and the function of, infant pointing behaviour. Many studies have converged on the view that early pointing reflects a motivation to share attention and interest with others. Under one view, it is the sharing of attention itself that is the ultimate function of pointing, and is an early manifestation of a uniquely human social cognition that is geared towards cooperation and collaboration. In the current study, we tested an alternative hypothesis in which the goal of pointing is not attention sharing itself, but the information-laden response that infants tend to receive as a result of sharing attention. If infants indeed point in order to obtain information, their pointing should be modulated by the perceived ability of the other to provide this information. In Experiment 1, 16-month-olds who interacted with a demonstrably knowledgeable experimenter pointed significantly more to novel objects than infants who interacted with an ignorant experimenter. In Experiment 2, we confirmed that this finding was due to the perceived competence of the experimenter rather than to the different ways in which the experimenter responded to infants' points. Our results suggest that one function of pointing in infancy is to obtain information from others, and that infants selectively elicit desired information from those whom they perceive could competently provide it.