Data provide strong evidence that studies of stress and cortisol release in infants must take into account basal level, circadian rhythm, and behavioral effects and employ appropriate statistical procedures. Participants were infants of two, four, and six months of age from whom salivary cortisol was obtained before and 15 minutes after an…

Designed to explore (1) developmental changes in exact and partial imitation of manual and facial movements, (2) model differences, and (3) gesture differences, this study observed infants at 2, 12, and 24 weeks of age. A hypothesis is proposed that links early nonselective behaviors and attributed imitation to emergence of imitative behavior…

Fixation time, smiling, vocalization, and fret/cry were recorded to obtain a complete picture of infants' responses to facial stimuli over the first year of life. Four stimuli were presented to 120 infants. Results of fixation data indicate that (1) there is a marked decrease in fixation toward facial stimuli within the first year, (2) at all ages…