Object play yields enormous benefits for infant development. However, little is known about natural play at home where most object interactions occur. We conducted frame-by-frame video analyses of spontaneous activity in two 2-h home visits with 13-month-old crawling infants and 13-, 18-, and 23-month-old walking infants (N = 40; 21 boys; 75%…

Our aim was to investigate why 16-month-old infants fail to master a novel tool-use action via observational learning. We hypothesized that 16-month-olds' difficulties may be due to not understanding the goal of the observed action. To test this hypothesis, we investigated whether showing infants an explicit demonstration of the goal of the action…

Two experiments were conducted to determine if infants attribute false beliefs to others when tested with the violation-of-expectancy procedure. In Experiment 1, the false-belief task was administered to 14- and 18-month-old infants. The procedure was identical to the one used by Onishi and Baillargeon (2005), except that two transparent boxes…

This study employed a new "anticipatory intervening" paradigm to tease apart false belief and ignorance-based interpretations of 18-month-olds' helpful informing. We investigated in three experiments whether 18-month-old infants inform an adult selectively about one of the two locations depending on the adult's belief about which of the two…

Warning others is a paradigm case of communicative helping and prospective action understanding. The current study addressed the ontogeny of warning in infants' gestural communication. We found that 12- and 18-month-olds ("n" = 84) spontaneously warned an adult by pointing out to her an aversive object hidden in her way…

Observed 12-month olds, with their mothers and independently, acting on objects from home and objects brought by the experimenter as new exemplars of previous toys. Found that conventional actions were more frequent in joint than in independent activity. In independent activity, conventional actions were more frequent with customary than with…

Evidence which suggests that pretend activities become increasingly independent of the presence of realistic objects is examined in this paper. Results of research on pretend behavior in children 1 1/2 - 2 years of age are described and analyzed. Striking changes in pretend behavior are shown to occur during the second year of life. Pretend play…

This study examines the degree to which young children are influenced by the familiarity of an adult participant in their pretend play with toys which vary in resemblance to highly prototypical objects (e.g., cup-like cups or doll-like dolls). A group of 29 children, mean age 21 months, was divided into two experimental groups balanced by sex; 15…

Reports a series of studies conducted to investigate possible differences in the exploratory manipulation and play behavior of human infants 7-1/2- 11-1/2 months of age as a function of the attributes of the stimulus, the familiarity of the subject with the stimuli, the age and sex of the infants, and individual differences. (Author/CS)

This illustrated booklet describes the physical, social, cognitive, sensory, and motor development of the typical infant during the first 12 months of life. Each of 12 chapters is concerned with successive months in a child's first year and is divided into three sections. Specific stimulating activities (i.e., handing toys to the infant's…