Objective: To examine the underlying mechanisms of adults' intended caregiving responses to cry sounds in a behavioral genetic design and to investigate the role of cry pitch and perceived urgency in sensitive and harsh caregiving responses. Methods: The sample consisted of 184 adult twin pairs (18-69 years), including males and females, parents…

Acoustic properties of the cries of 14 infants were evaluated at both 2 and 4 weeks of age when the infants were lying in a supine position and when they were sitting upright in a car seat. In the upright position, infants' breathing was more rapid and showed less individual variability. The fundamental frequency of their cries increased in the…

Reports a study of 110 newborn infants' responses to the heelstick procedure to draw blood samples, and of the responses of 40 of those infants to their first inoculations at two months of age. Discusses measures of distress; stability of reactivity across time; and individual differences and health of the infant as factors in reactivity. (NH)

Used multilevel analyses to examined the amounts of time infants spent asleep, awake, content, feeding, fussing, and crying at 2, 6, 12, and 40 weeks of age. Found that day-to-day fluctuations accounted for between 44 and 53% of the variance in amounts of time sleeping, fussing, and crying. (MDM)

The impact of differences in maternal self-efficacy and infant difficulty on mothers' sensitivity to small changes in the fundamental frequency of an audiotaped infant's cry was explored in 2 experiments. The experiments share in common experimental manipulations of infant difficulty, a laboratory derived measure of maternal efficacy (low,…