A live video was used to study the development of visual self-recognition in a cross-sectional sample of 152 typically developing French children aged between 15 months to 6 years. Three reactions to a mark placed on the child's cheek without their knowledge were studied: the touch of the mark with their hand, the ocular responsiveness to the mark…

Fourteen-month-olds selectively imitated a sub-efficient means (illuminating a lightbox by a head-touch) when this was modeled by linguistic ingroup members in video-demonstrations. A follow-up study with slightly older infants, however, could replicate this effect only in a video-demonstration context. Hence it still remains unclear whether…

This research investigates the development of constraints in word learning. Previous experiments have shown that as infants gain more knowledge of native language structure, they become more selective about the forms that they accept as labels. However, the developmental pattern exhibited depends greatly on the way that infants are introduced to…

It has been suggested that due to functional similarity, sortal object individuation might be a primordial form of psychological essentialism. For example, the relative independence of identity judgment from perceived surface features is a characteristic of essentialist reasoning. Also, infants engaging in sortal object individuation pay more…

Spatial play in early childhood is associated with a variety of spatial and cognitive skills. However, these associations are often derived from studies in which different tasks are used across different age ranges, leaving open the question of how children's natural behaviors during spatial play develop from infancy into the early preschool…

This experiment tests the age at which left-to-right spatial associations found in infancy shift to culture-specific spatial biases in later childhood, for both numerical and non-numerical information. Children ages 1-5 years (N = 320) were tested within an eye-tracking paradigm which required passive viewing of a video portraying a spatial…

The development of theory of mind (ToM) in infancy has been mainly documented through studies conducted on a single age group with a single task. Very few studies have examined ToM abilities other than false belief, and very few studies have used a within-subjects design. During 2 testing sessions, infants aged 14 and 18 months old were…

Children's lexical processing speed at 18 to 25 months of age has been linked to concurrent and later language abilities. In the current study, we extend this finding to children aged 36 months. Children (N = 126) participated in a lexical processing task in which they viewed two static images on noun trials (e.g., an ear of corn and a hat), or…

Humans are motivated to connect with others and are sensitive to social exclusion--intentionally leaving out others. This ability to detect social exclusion is suggested to be evolutionarily adaptive, biologically hardwired, and an important feature of social-cognitive development. Yet it is unclear when children start to independently detect…

This study investigates the importance of object function (action-object-outcome relations) on object individuation in infancy. Five experiments examined the ability of 9.5- and 12-month-old infants to individuate simple geometric objects in a manual search design. Experiments 1 through 4 (12-month-olds, N = 128) provided several combinations of…

Although much research has examined the development of orienting to social directional cues (e.g., eye gaze), little is known about the development of orienting to nonsocial directional cues, such as arrows. Arrow cues have been used in numerous studies as a means to study attentional orienting, but the development of children's understanding of…

Recent studies indicate the need to investigate the sources of toddlers' understanding of another person's pretense. The present study is a cultural and longitudinal extension of the work of Lillard and Witherington (2004), who claimed that mothers modify their behaviors during pretense and that the some of these behavior modifications help their…

Executive functions play an important role in cognitive development, and during the preschool years especially, children's performance is limited in tasks that demand flexibility in their behavior. We asked whether preschoolers would exhibit limitations when they are required to apply a general rule in the context of novel stimuli on every trial…

In 4 experiments, we examined 16- and 20-month-old infants' understanding of proper names and count nouns. In each experiment, infants were taught a novel word modeled linguistically as either a proper name (e.g., "DAXY") or a count noun (e.g., "a DAXY") for a stuffed animal shown on a puppet stage. This animal was moved to a new location on the…

In the studies presented here, infants' understanding of others' attention was assessed when gaze direction cues were not diagnostic. Fourteen-, 18- and 24-month-olds witnessed an adult look to the side of an object and express excitement. In 1 experimental condition this object was new for the adult because she was not present while the child and…