Two aspects of the cognitive development of a 14- to 18-month-old blind child are reported: the development of procedures for the intentional control of objects and the development of certain classificatory skills. (Author)

Chimpanzees ("Pan troglodytes") and bonobos ("Pan paniscus") (Study 1) and 18- and 24-month-old human children (Study 2) participated in a novel communicative task. A human experimenter (E) hid food or a toy in one of two opaque containers before gesturing towards the reward's location in one of two ways. In the Informing condition, she attempted…

This study tested participants' preparedness to acknowledge that an object could change as a result of magical intervention. Six- and 9-year-old children and adults treated perceived and imagined objects as being equally permanent. Adults treated a fantastic object as significantly less permanent than either perceived or imagined objects. Results…

The phenomenon called "aging out" includes approximately 20,000 young people who enter adulthood directly from foster care each year (U.S. Department of Health and Human Services, 2005). The number of youth and young adults who aged out of care in the U.S. in 2005, the year for which the most current statistics are available, increased 48 percent…

Preferential-looking studies suggest that by 2 months of age, infants may have knowledge about some object properties, such as solidity. Manual search studies of toddlers examining these same concepts, however, have failed to provide evidence for the same understanding. Investigators have recently attempted to reconcile this disparity but failed…

Eighteen-month-old children performed sorting tasks and their parents completed checklists of words used by the children. Children who performed exhaustive grouping, or grouping of objects of different kinds in different locations, were reported as using more words than children who did not perform exhaustive grouping. (BC)

In three shape-constancy experiments, 4- and 7-year olds viewed a circular disc oriented at a slant. All subjects exaggerated circularity of the disc when they knew the object was a circle. Findings suggest that knowledge of reality contaminates judgments of appearance in circle task and this is the same bias that features in realist errors in…

The emerging ability to represent an oscillating moving object over occlusions was studied in 7-21-week-old infants. The object moved at 0.25 Hz and was either occluded at the center of the trajectory (for 0.3 s) or at one turning point (for 0.7 s). Each trial lasted for 20 s. Both eye and head movements were measured. By using two kinds of…

Recent research on infants' responses to occlusion and containment events indicates that, although some violations of the continuity principle are detected at an early age e.g. Aguiar, A., & Baillargeon, R. (1999). 2.5-month-old infants' reasoning about when objects should and should not be occluded. Cognitive Psychology 39, 116-157; Hespos, S.…

Stimulus preference assessments for individuals with developmental disabilities typically involve offering choices among stimuli and providing immediate access to the chosen stimuli. Several researchers have explored the utility of presenting choices verbally, thereby obviating the need to present the choices in tangible form and deliver access to…

Attempts to clarify the meaning of differentiation in the Piagetian concept of object permanence. (BD)

This study tested Piaget's explanation of infants' perseverative error in manual search by comparing searches when the object was (1) hidden, (2) covered but visible, and (3) uncovered. Errors occurred under all three conditions, with conflict at a maximum when the object was hidden. (Author/JMB)

Statistical analysis of many studies on Piaget's stage 4 object concept attempts to synthesize available quantitative data. Factors of this "meta-analysis" include: (1) effects of age; (2) number of A trials; (3) length of delay between hiding and search; (4) number of locations; and (5) visual properties of hiding arrays. Includes…

Investigates the degree to which object familiarity and motivational factors influence infants' search behavior in an object-permanence test. (Author/MP)

This study examined two alternative interpretations of violation-of-expectation findings that young infants can represent hidden objects. Findings indicated that 5-month-olds succeeded in reasoning about the interaction of a visible and a hidden object even though the 2 objects were never simultaneously visible and a 3- or 4-minute delay preceded…