Age differences in play were examined cross-sectionally in children at 7, 9, 15, and 10 months of age. (BRT)

Investigates whether 6- to 12-month-old infants' exposure to the successful search behavior of a sibling in two object-concept tasks would enhance infants' subsequent performance on these tasks. (HOD)

The phenomenon of fear of strangers (FS) is reviewed in light of recent findings in neurophysiology, ethology, developmental and cognitive psychology. (Author/TW)

Some of the findings of a longitudinal study of three infants between their 11th and 22nd months to document development of linguistic expression of the agent concept indicated that first vocalizations were inconsistently associated with nonverbal agentive behaviors and later mature utterances coded agent-action-recipient events. (MC)

Evaluates the degree to which the social-referencing perspective provides a valid explanation of some features of infant behavior. (MP)

Infants were classified as high or low in differential vocal responsiveness (DVR), and tested for degree of response to stimulation by a stranger and to stimulation by their mothers. The infants' DVR classification was related to scores on the Stanford-Binet and the Illinois Test of Psycholinguistic Abilities. (Author/SS)

A total of eighty 9-month-old infants were presented with a problem consisting of several different conditions which separated response, position on a table, and absolute spatial position as factors leading to errors in search for hidden objects. (MS)

Proposes a theoretical sequence of cognitive developments as influencing representational play and language in the second year of life. Structural and temporal links between play and language indicate influence of developing mental representation, but variation in timing of developments points to influence of variables. (ET)

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.…

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…

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…

Examined the effect of functional values of stimuli on orienting response elicitation. Subjects were 50 4-month-old infants and were randomly assigned to 1 of 3 experimental conditions. Results suggested the importance of taking into account the functional value of stimuli when analyzing infant attention. (MOK)