Infant cortisol and behavioral responses to receiving one versus two inoculations on one pediatric office visit were observed at two and six months of age. The findings indicate a developmental trend for a decline over age in adrenocortical reactivity to inoculation for infants showing a cortisol release following perturbation. Results were…

Seven experiments study the decrease in response to repeated visual stimulation in children's first four years. (DR)

Outlines a method by which observation time as measured by visual fixation on an object in the visual field can be predicted for N items viewed simultaneously in the field when the time for observing each item presented singly is known. (Author/MG)

Examined whether early differences in stress reactivity were related to self-recognition at 18 months. Found that self-recognition was related to greater cortisol response and less rapid quieting at 6 to 18 months, whereas cortisol and quieting responses of 2- to 4-month-olds did not differentiate self-recognizers and non-self-recognizers,…

Examines early differences in mother-infant interaction as a function of infant birth order and birth spacing. Mother and infant behaviors were observed and recorded in the home for a two-hour period. (SS)

Discusses the social development of infants in terms of a set of tasks which include identity, culturation, and reproduction. Focuses on the task of identity, the role of self-awareness in relationships, and the relationship between identity and emotional life. (RJC)

This study investigated the common practice in infant research of eliminating from reported data large numbers of subjects who prove uncooperative (sleepy, fatigued, fussy) during the experiment. It was suggested that these excluded infants constitute a special class of subjects and that the inclusion of their data would greatly alter the research…

Data from infants unable to complete experimental sessions were compared to those for whom there were complete data. Results suggest that the elimination of large numbers of infants may have a potentially biasing effect on reported data. (Authors)

Studied individual differences in reactivity in 40 newborns. Measures of reactivity were related during the first two months of extrauterine life. (RJC)

This study examined the effect of different types of loss of control on the quality and quantity of the frustration response in 4- to 6-month-old infants. To establish an expectancy, all infants received 4 minutes of contingency training in which infants were presented with slides and music after they performed a pulling response with their right…

Examined relations between reactivity (peak response) and regulation (response dampening) in 6-month-olds' cortisol and behavioral responses to inoculation. Found that reactivity and regulation were unrelated for both cortisol and behavior, suggesting both measures are needed to characterize more accurately infant response to stress. Found…

Examined the effect of maternal soothing to infant inoculation as well as everyday distress on infant cortisol and behavioral responses to stress in two samples of infants between 2 and 6 months of age. Found no evidence that maternal soothing reduced cortisol or behavioral-stress responses, despite evidence for cross-time stability and…

This study examined the behavioral (arm, facial) and autonomic (heart rate, respiratory sinus arrhythmia [RSA], and adrenocortical axis) reactivity of 56 4-month-old infants in response to contingency learning and extinction-induced frustration. During learning, infants displayed increases in operant arm response and positive emotional…