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)

Eight- to 12-month-olds might make A-not-B errors, knowing the object is in B but searching at A because of ancillary (attention, inhibitory, or motor memory) deficits, or they might genuinely believe the object is in A (conceptual deficit). This study examined how diligently infants searched for a hidden object they never found. An object was…

Evaluated in three experiments a dynamic systems theory account of perseverative errors on "A-not-B" task. Found that 9-month-olds perseverated when reaching for identical targets, but made nonperseverative responses when reaching in the presence of a highly distinctive B target. Reach direction was jointly determined by target's…

Four experiments examined 8- to 12-month olds on search and nonsearch A not B tasks, a one-location task, and control tasks. Results indicated memory for where object was hidden and expectations of where it should be found. The effect occurred at delays at which infants made the A not B error when searching, and at a longer 15-second delay.…