How do age and the acquisition of independent walking relate to changes in infants' everyday experiences? We used a novel ecological momentary assessment (EMA) method to gather caregiver reports of infants' restraint, body position, and object holding via text messages sparsely sampled across multiple days of home life at 10, 11, 12, and 13 months…

Learning to walk leads to an increase in language abilities; however, the underlying mechanisms accounting for this relation remain unclear. Investigating the quality of early gait control may offer some insights. The purpose of this study was to: (1) quantify how 13-month-olds (n = 39; 39% male) and 24-month-olds (n = 39; 59% male) adapt gait…

This research examined the development of adaptive generalization in infants' object-directed actions. Infants ages 9 and 12 months participated in an object manipulation task with stimulus objects from 2 categories that differed in shape and weight and that bore a consistent shape or weight correspondence. Weight differences between…

A hierarchical progression in infants' ability to use surface features, such as color, as a basis for object individuation in the first year has been well established (Tremoulet, Leslie, & Hall, 2000; Wilcox, 1999). There is evidence, however, that infants' sensitivity to surface features can be increased through multisensory (i.e.,…

The authors examined 14- to 26-month-old infants' understanding of the spatial relationships between objects and apertures in an object manipulation task. The task was to insert objects with various cross-sections (circular, square, rectangular, ellipsoid, and triangular) into fitting apertures. A successful solution required the infant to…

Examined infants' categorization using object manipulation tasks that involved objects that were models of animals, vehicles, or furniture. Objects were normal, had anomalous moving parts (such as a dog with wheels), or had different textures. Found that 14- to 22-month olds attended to the parts and structural configuration of objects, but not to…

Studies 12- to 24-month-olds in a series of videotaped tasks assessing single object manipulation, relational play, pretend play, distractibility and persistence. Develops eight relatively subtle measures of three aspects of individual differences in infant behavior: developmental level, attention span, and exploratory diversity. (Author/NH)

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)