Four experiments examined 8-month-olds' ability to reason about collections of objects. Findings suggested that infants' expectations about object behavior do not automatically apply to any and all portions of matter within the visual field. The behavior of an entity and infants' prior experience played roles in determining whether infants will…

Familiarized 6- and 8-month-olds with speech sounds from a phonetic continuum, exhibiting a bimodal or unimodal frequency distribution. Found that only infants in the bimodal condition discriminated tokens from the endpoints of the continuum. Results demonstrate that infants are sensitive to the statistical distribution of speech sounds in the…

Tested in six experiments young infants' sensitivity to vowel and gender information in faces and voices. Found that 4.5-month-olds showed no evidence of matching face and voice based on gender, but were able to ignore irrelevant gender information and match based on the vowel. Robust evidence of ability to match based on gender was not evident…

Two experiments examined whether infants are sensitive to holistic combinations of line junctions in 2-D images that adults use to derive overall 3-D structure. Results suggested that 3-month-olds are sensitive to holistic combinations of line junctions that adults use to derive 3-D information but also selectively attend to these 3-D cues in…

Investigated 3-month-olds' categorization of animals and vehicles based on static and dynamic attributes. Found that regardless of viewing static or dynamic displays, infants showed habituation to varying exemplars from the same category, dishabituated to an exemplar from a novel category, and showed a novelty preference for a novel-category…

Recorded reaching and looking preferences and movement kinematics among 5- to 15-month-olds divided into 3 age groups. Found that 5- to 12-month-olds preferred looking first at a large object; 8.5- to 12-month-olds showed preference for reaching to smaller (graspable) objects. Kinematic measures suggested that onset of object-oriented action…

This study explored different gradations of emulation in the imitation of actions on objects by 17-month-olds. Experiment 1 established levels of behavioral reproduction following prerecorded video demonstrations similar to those levels following live demonstrations. In Experiment 2, two digitally modified videos, where object movements or body…

Infant-control habituation methodology, although serving the research community well, has never been carefully analyzed. A main use is to equate infants in their level of habituation prior to experimental manipulations in a posthabituation phase. When studied analytically and with simulation, it is found to have serious difficulties. It…

Previous research has investigated the effect of maternal soothing behaviors on reducing infant reactivity but not the differential effects of specific maternal behaviors on infant stress responses. The present study investigated maternal regulation of 2- and 6-month-olds' responses to an inoculation and found a significant decline with age in…

Several investigators find that infants fail to use property information to individuate objects until 12 months of age (e.g., Xu & Carey, 1996), while others find that infants successfully employ property information in the service of object individuation at 9.5 months (e.g., Wilcox & Baillargeon, 1998a). This study investigated…

Young infants use caregivers' emotional expressions to guide their behavior in novel, ambiguous situations. This skill, known as social referencing, likely involves at least 3 separate abilities: (a) looking at an adult in an unfamiliar situation, (b) associating that adult's emotion with the novel situation, and (c) regulating their own…

In 3 experiments, the author investigated 16- to 20-month-old infants' attention to dynamic and static parts in learning about self-propelled objects. In Experiment 1, infants were habituated to simple noncausal events in which a geometric figure with a single moving part started to move without physical contact from an identical geometric figure…

Paying attention to development and the earliest possible detection of relevant development disturbances during the first year are among the essential responsibilities of the paediatrician. We present a questionnaire for the documentation of the developmental progress of babies, having been compiled in the Loczy Institute in Budapest, according to…

Two-month-old infants (N = 29) participated in face-to-face interactions with their mothers and with strangers. The contingent responsiveness for smiles and vocalizations, while attending to the partner, was assessed for each partner in both interactions. For smiles and for vocalizations, infants were less responsive to the stranger relative to…

This study examined the effect of different types of loss of control on the quality and quantity of the frustration response in 4- to 6-month-old infants. To establish an expectancy, all infants received 4 minutes of contingency training in which infants were presented with slides and music after they performed a pulling response with their right…