Confirms the existence of a right-hemisphere advantage in the process of discriminating between face stimuli. The advantage was weaker in females than in males. No hemispheric transfer of learning was observed. Subjects were 18 infants of 42 weeks who were presented with an operant conditioning situation in which they discriminated between their…

Two experiments examined the origins of joint visual attention in 6- to 11-month-olds with a training procedure. Results indicated that joint visual attention does not reliably appear prior to 10 months; from about 8 months, a gaze-following response can be learned; and simple learning is not sufficient as the mechanism through which joint…

Two experiments used object-manipulation tasks to examine whether one- to two-year-olds form superordinate-like categories by attending to object parts. Findings indicated that 14- and 18-month-olds behaved systematically toward categories with different, but not matching, parts. Without part differences, none formed superordinate categories.…

Reviews the construct of attachment, its role as a motivational system in infancy, and its development in the first three years. Emphasizes that attachment must be assessed in the context of particular infant-parent relationships, and reviews specific infant and caregiver behaviors salient to the assessment of attachment. (Author/CR)

Examined whether early individual differences in look duration were related to general mechanisms of the infant nervous system combining attention and emotion. Found significant positive correlations between attention measures and duration of facial expressions of pain/distress after vaccinations at 3, 5, and 11 months. Concluded that individual…

Explored genetic and environmental underpinnings of temperamental differences in 3- to 16-month-old twins and their parents. Found that additive genetic and shared environmental effects best represented smiling, laughter, and duration of orienting. Shared environmental effects fully accounted for co-twin similarity for soothability. Additive…

Three experiments used a familiarization/novelty or a habituation/dishabituation procedure to examine developmental change in infants' tendency to parse exemplars into separate categories. Results indicated that 10-month olds appeared to form differentiated categories, whereas 4- and 7-month olds formed a single category to include the range of…

This study examined how novel words foster the formation of object categories for 12- to 13-month olds. Results indicated that by 12 to 13 months, infants have begun to distinguish between novel words presented as count nouns versus adjectives in fluent, infant-directed speech, and that infants' expectations for novel words accord with this…

Two studies examined whether 1-year olds' name learning during joint attention was guided by expectation that names will be in the form of spoken words. Results showed that 13-month olds, but not 20-month olds, learned a new sound/object correspondence, as evidenced by their choosing targets reliably in responses to hearing the word or sound on…

Examined exogenous orienting among infants between 7 and 21 weeks of age in 2 experiments using display with multiple potential attention targets. Found that as early as 7 weeks of age, sensitivity for a small moving stimulus can be significantly influenced by the simultaneous presence of competing attention targets. Found large increases in…

Three experiments investigated use of visual input and body movement input arising from movement through the world on spatial orientation. Experiments involved infants searching for a toy hidden in one of two containers. Findings indicated that search was best after infant movement in a lit environment prior to searching; all other conditions led…

Six experiments examined infants' ability to associate nonsense words with two causal actions: pushing and pulling. Eighteen-month-olds, but not 14-month-olds, formed word-action associations. Fourteen-month-olds discriminated a change in label but not a change in action when the other was held constant. When language labels were replaced with…

Examined 8- to 10-month-olds' responses to standard procedures eliciting joy, fear, anger, and discomfort. Found that response parameters to standard procedures cohered strongly within each episode. Responses cohered across same-emotion episodes, except for anger. Responses and father-reported temperament related to infant's emotional tone in…

Two experiments examined 6-month olds' ability to categorize natural infant-directed utterances. Infants heard seven different tokens from one class of utterance (comforting, approving). Findings indicated that infants who later heard a test stimulus from the unfamiliar class showed response recovery, whereas those who heard a novel stimulus from…

Evaluated infants' ability to form new object categories based on either visual or naming information at 16 and 20 months using an object manipulation task. Found that infants at both ages showed evidence of using visual information to categorize the objects. Only 20-month-olds used naming information. Found a correlation between vocabulary size…