Deferred imitation of object-related actions was studied at two ages, 12 and 18 months, to examine development of competence in observational learning. Three task categories were investigated: simple/single reiterative, and sequentially coordinated actions. Examination of partial successes at both ages was useful for suggesting phases in…

Sequences of mastery behavior were analyzed in a sample of 67 infants 6 to 12 months old. Authors computed (a) frequencies of six categories of mastery behavior, transitional probabilities, and z scores for each behavior change, and (b) transitions from a mastery behavior to positive affect. Changes in frequencies and similarity in organization…

Reports two studies of infant exploration. In the first, age and characteristics of the object stimuli influenced 6-, 9- and 12-month-olds who manipulated a series of objects. Results of the second study suggested that different kinds of manipulation are used to explore changes in shape, texture, and weight. (Author/CB)

Infants ranging from 6 to 12 months were randomly assigned to one of three conditions: (1) allowed to look at a specified object, (2) allowed to look at and manipulate it, or (3) allowed to look at the object and to manipulate the transparent box in which it was encased. (JMB)

Compared mothers' play with infants with Down syndrome (DSC) and typically developing children (TDC) matched for mental or chronological age. Found that TDC mothers exhibited more object demonstrations with their developmentally younger children, who showed less object play. DSC mothers were more directive and supportive than mothers of younger…

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.…

Evaluated 9-, 14-, and 19-month olds' strategies as they grasped and used spoons presented with the handle alternately oriented to left or right. Found that younger children reached with their preferred hand, disregarding the item's orientation. Older children anticipated the problem, alternated the hand used, and achieved an efficient radial grip…

Studied the early development of exploratory behavior in 99 infants of 2-5 months. Results show that there are significant changes in spontaneous multimodal exploration of a novel object between 2 and 5 months. (RJC)