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…