Two studies tested whether 12- and 24-month olds' self-knowledge differed from their knowledge of others (mother or inanimate object), or whether toddlers' knowledge of persons (self and mother) differed from knowledge of objects. Results showed that 12-month olds were more sensitive than older toddlers to perceptual features of objects. Data were…

Twenty-five infants were tested every two weeks on the AB Object Permanence Task, from the time they first reached for a hidden object until they were 12 months old. Results indicate that the AB provides an index of the ability to carry out an intention based on stored information despite a conflicting habitual tendency. (Author/RH)

Observed the reactions of 3.5-month-old infants looking at a carrot that should have but did not appear in a window after passing behind a screen. The results of this and several similar experiments indicated that 3.5-month-old infants are able to represent and reason about hidden objects. (BC)