As humans, we are attuned to the moods and emotions of others. This understanding of emotions enables us to interpret other people's actions on the basis of their emotional displays. However, the development of this capacity is not well understood. Here we show a developmental pattern in 10- and 14-month-old infants' sensitivity to others'…

The postural sway patterns of newly standing infants were compared under two conditions: standing while holding a toy and standing while not holding a toy. Infants exhibited a lower magnitude of postural sway and more complex sway patterns when holding the toy. These changes suggest that infants adapt postural sway in a manner that facilitates…

The goal of this research was to investigate the extent to which young children use the past reliability of another person's statements to make inferences about the accuracy of that person's claims about a hidden toy. When children interacted with a previously reliable speaker, both 30- and 36-month-olds searched in the new location of the toy, in…

Children can identify owners either by seeing a person in possession of an object (a visual cue) and inferring that they are the owner or by hearing testimony about a claim of ownership (a verbal cue). A total of 391 children between 2.5 and 6 years of age were tested in three experiments assessing how children identify owners when these two cues…

Despite a growing interest in the question of tool-use development in infants, no study so far has systematically investigated how learning to use a tool to retrieve an out-of-reach object progresses with age. This was the first aim of this study, in which 60 infants, aged 14, 16, 18, 20, and 22 months, were presented with an attractive toy and a…

Dynamic spatial indexing is the ability to encode, remember, and track the location of complex events. For example, in a previous study, 6-month-old infants were familiarized to a toy making a particular sound in a particular location, and later they fixated that empty location when they heard the sound presented alone ("Journal of Experimental…

In this study, we addressed the question of the nature of the information needed by 13-month-old infants to understand another agent's intentions. In two experiments, an experimenter was either unable or unwilling to give a toy to an infant. Importantly, an implement (a gutter in which the toy could roll down toward the infant) was used to make…

The purpose of this study was to investigate the accuracy of parents' perception of children's reaching limits in a risk scenario. A sample of 68 parents of 1- to 4-year-olds were asked to make a prior estimate of their children's behavior and action limits in a task that involved retrieving a toy out of the water. The action modes used for…

Five experiments were conducted to investigate infants' ability to transfer actions learned via imitation to new objects and to examine what components of the original context are critical to such transfer. Infants of 15 months observed an experimenter perform an action with one or two toys and then were offered a novel toy that was not…

A multitask battery tapping nonverbal memory and language skills was used to assess 60 children at 18, 24, and 30 months of age. Analyses focused on the degree to which language, working memory, and deliberate memory skills were linked concurrently to children's Elicited Imitation task performance and whether the patterns of association varied…

Evidence that young children often claim ownership of their partner's contributions to an earlier collaborative activity, the "appropriation bias", has been attributed to shared intentionality ("Cognitive Development" (1998) 13, 91-108). The current investigation explored this notion by examining individual differences in the bias among 4- and…

Infants rapidly accrue information via imitation from multiple sources, including television and electronic toys. In two experiments, we examined whether adding sound effects to video or live demonstrations would influence imitation by 6-, 12-, and 18-month-olds. In Experiment 1, we added matching and mismatching sound effects to target actions…

Discriminative stimulus control over sex-typed play behaviors was investigated in five boys, aged 5-8 years, who had childhood cross-gender identification. Sex-typed play was found to vary as a function of social stimulus condition and type of response required, but all children exhibited predominantly feminine play while alone in the playroom.…

Effect of peer presence on the sex-typed toy choices of three and four year olds (N=62) was investigated in a repeated measures experimental design. (MP)