Recent research indicates that toddlers can monitor others' conversations, raising the possibility that they can acquire vocabulary in this way. Three studies examined 2-year-olds' (N = 88) ability to learn novel words when overhearing these words used by others. Children aged 2,6 were equally good at learning novel words-both object labels and action verbs-when they were overhearers as when th...

Our goal in this study was to examine whether controlled pretense signal presentation by an adult promoted pretend play behavior in toddlers. Seventy-two Japanese toddlers (24 toddlers in the 18-month-old group, 24 toddlers in the 24-month-old group, and 24 toddlers in the 30-month-old group) participated in one of two experimental conditions: signal and signal-less. In the signal condition, th...

Toddlers are remarkably prosocial toward adults, yet little is known about their helping behavior toward peers. In the present study with 18- and 30-month-old toddlers (n = 192, 48 dyads per age group), one child needed help reaching an object to continue a task that was engaging for both children. The object was within reach of the second child who helped significantly more often compared to a...

Joint-improvisation is not only an open-ended creative action that two or more people perform together in the context of an artistic performance (e.g., theatre, music or dance). Joint-improvisation also takes place in daily life activities when humans take part in collective performance such as toddlers at play or adults engaged in a conversation. In the context of this article, joint-improvisa...

The current study examined the intergenerational transmission of role reversal within a developmental psychopathology framework. Role reversal is a relationship disturbance in which a parent looks to a child to meet the parent's need for comfort, parenting, intimacy, or play, and the child attempts to meet these needs. In a normative sample, n=138, fathers and mothers reported on childhood role...

To what extent do toddlers have shared vocabularies? We examined CDI data collected from 14,607 infants and toddlers in five countries and measured the amount of variability between individual lexicons during development for both comprehension and production. Early lexicons are highly overlapping. However, beyond 100 words, toddlers share more words with other toddlers in comprehension than in ...

Infant-parent interactions occur across many situations, yet most home-based assessments of parenting behaviors are conducted under conditions of low stress, such as free play. In this study, low-income mothers from the Early Head Start Research and Evaluation Project were observed at home interacting with their 14-month-olds in the mildly stressful "High Chair" assessment (n=1718 dyads). This ...

Syntax allows human beings to build an infinite number of new sentences from a finite stock of words. Because toddlers typically utter only one or two words at a time, they have been thought to have no syntax. Using event-related potentials (ERPs), we demonstrated that 2-year-olds do compute syntactic structure when listening to spoken sentences. We observed an early left-lateralized brain resp...

Children learn from their environments and their caregivers. To capitalize on learning opportunities, young children have to recognize familiar words efficiently by integrating contextual cues across word boundaries. Previous research has shown that adults can use phonetic cues from anticipatory coarticulation during word recognition. We asked whether 18-24 month-olds (n=29) used coarticulatory...