Infants greatly refine their ability to discriminate language sounds by 12 months, yet 14-month-olds appear to confuse similar-sounding novel words. Two explanations could account for this phenomenon: infants initially have incomplete phoneme representations, suggesting developmental discontinuity; or word-learning demands interfere with use of…

Two preferential-reaching experiments explored 5- and 7-month-olds' sensitivity to pictorial depth cues. In the first experiment, infants viewed a display in which texture gradients, linear perspective of the surface contours, and relative height in the visual field provided information that two objects were at different distances. Five- and…

In this study, we asked whether 14- and 18-month-old infants use the experiences they have previously shared with others when deciding what to point to for them declaratively. After sharing a particular type of referent with an adult in an excited manner, 18-month-olds subsequently found a picture of that type of referent more worthy of…

Halberda (2003) demonstrated that 17-month-old infants, but not 14- or 16-month-olds, use a strategy known as mutual exclusivity (ME) to identify the meanings of new words. When 17-month-olds were presented with a novel word in an intermodal preferential looking task, they preferentially fixated a novel object over an object for which they already…

Infants (n = 24, mean age 13 months and n = 24, mean age 19 months) were tested on an extension of the method introduced by Tomasello and Haberl (2003) to examine the understanding of another person's interest in a novel object. Four objects were presented serially. For two objects, infants played with an experimenter. The infant played with one…

Like faces, bodies are significant sources of social information. However, research suggests that infants do not develop body representation (i.e., knowledge about typical human bodies) until the second year of life, although they are sensitive to facial information much earlier. Yet, previous research only examined whether infants are sensitive…

Behne, Carpenter, Call, and Tomasello (2005) showed that 9- to 18-month-olds, but not 6-month-olds, differentiated between people who were unwilling and unable to share toys. As the outcome of the two tasks is the same (i.e., the toy is not shared), the infants must respond to the different goals of the actor. However, visual habituation paradigms…

Toward the end of their first year of life, infants' overly specified word representations are thought to give way to more abstract ones, which helps them to better cope with variation not relevant to word identity (e.g., voice and affect). This developmental change may help infants process the ambient language more efficiently, thus enabling…

The developmental origins of sharing remain little understood. Using procedures adapted from research on prosocial behavior in chimpanzees, we presented 18- and 25-month-old children with a sharing task in which they could choose to deliver food to themselves only, or to both themselves and another person, thereby making it possible for them to…

The present study examines coviewing of "Baby Mozart" by 6- to 18-month-old infants and their caregivers under naturalistic conditions. We had two questions. First, extending the method of Barr, Zack, Garcia, and Muentener (Infancy, 13 [2008], 30-56) to a younger population, we asked if age, prior exposure, and caregiver verbal input would predict…

This study examined the developmental course of infants' attentional preferences for 3 types of infant-directed affective intent, which have been shown to be commonly used at particular ages in the first year of life. Specifically, Kitamura and Burnham (2003) found mothers' tone of voice in infant-directed speech is most comforting between birth…

Two experiments used a mutual imitation paradigm to assess 9-, 14-, and 18-month-old infants' developing understanding of intentions in others. In the first study, 1 experimenter imitated the infants' actions, and another experimenter performed contingent but different actions on an identical toy. From 9 months of age, infants show discrimination…

When do infants begin to communicate positive affect about physical objects to their social partners? We examined developmental changes in the timing of smiles during episodes of initiating joint attention that involved an infant gazing between an object and a social partner. Twenty-six typically developing infants were observed at 8, 10, and 12…

Developmental studies of face processing have revealed age-related changes in how infants allocate neurophysiological resources to the face of a caregiver and an unfamiliar adult. We hypothesize that developmental changes in how infants interact with their caregiver are related to the changes in brain response. We studied 6-month-olds because this…

We used an optimized configuration of the delayed-response task to explore the ability of young infants to remember which of 2 locations was correct across 12 trials after a 1- to 2-sec delay. Performance improved with age, particularly after 5.5 months. These findings suggest an onset of appreciable working memory for many infants in the middle…