The Stressfulness of Separation among Nine-Month-Old Infants: Effects of Social Context Variables and Infant Temperament

Abstract

This manuscript reports on the results of 2 experiments dealing with behavioral and adrenocortical responses to separation among 9-month-old human infants. In both experiments the social context of separation was manipulated. The results of Experiment 1 yielded evidence of a statistically significant adrenocortical response to 30 min of separation under conditions in which the substitute caregiver responded sensitivity to infant distress, but was busy and relatively noninteractive when babies were not distressed during the separation period. Altering the behavior of the substitute caregiver such that she was warm, responsive, and interactive throughout the separation produced a significant reduction in adrenocortical activity and in negative affect. In fact, these measures were not significantly different than those obtained when the mother and infant remained together in the playroom (No Separation). In Experiment 2, the effects of group versus singleton care were examined using the less stressful mode of substitute caregiving as described above. No significant condition differences in behavioral distress or cortisol were found. Furthermore, neither condition elicited a significant increase in cortisol over basal levels. Finally, these data provide evidence that maternal reports of infant Distress to Limits temperament, using Rothbart's Infant Behavior Questionnaire, predict adrenocortical responses to separation, while reports of Fear of Novelty do not.

Adrenocortical and Behavioral Predictors of Immune Responses to Starting School

“…Circadian rhythms in cortisol secretion appear by about 3 mo of age in human infants (52,87), and a decline in cortisol response to stress over the first months of life has been noted (50). In a series of studies by Gunnar (46,47,49) and Lewis (51,52) and their colleagues, cortisol responses have been studied in relation to a diversity of environmental events and perturbations, including maternal-infant separations, car rides, swimming lessons, and routine immunizations. Individual differences in cortisol response in such settings have been shown to be reliable (52,53), related to aspects of emotional temperament (49), and modifiable by altering aspects of the social environment (47,88).…”

“…The current study was designed to address both difficulties by using behavioral reactivity and a noninvasive measure of adrenocortical reactivity-salivary cortisol-to predict changes in immune status after the normative stress of beginning school. Past studies have documented the validity of salivary cortisol determinations in young children (43,44), and increases in salivary cortisol have been shown reliably to accompany diverse physical and emotional stressors (45)(46)(47)(48)(49)(50)(51)(52). Further, the intensity of a noxious event has proved predictive of the magnitude of salivary cortisol responses (53), and glucocorticoids are known to affect leukocyte circulatory kinetics and cell functions (54,55).…”

Physiological effects of separation and reunion in relation to attachment and temperament in young children

“…Human studies on HPA reactivity have revealed increasing cortisol levels in infants when they were separated from the mother and left with an unfamiliar babysitter, compared to being alone with the mother (Gunnar, Larson, Hertsgaard, Harris, & Broderson, 1992). In addition, higher cortisol levels were found for insecurely attached infants (Hertsgaard, Gunnar, Erickson, & Nachmias, 1995;Spangler & Grossman, 1993;Spangler & Schieche, 1998) and for infants with a combination of inhibited approach (e.g., to novelty of social situations) and insecure attachment (Gunnar, Brodersen, Nachmias, Buss, & Rigatuso, 1996;Nachmias, Gunnar, Mangelsdorf, Parritz, & Buss, 1996).…”

Patterns of cortisol reactivity in African‐American neonates from low‐income environments

“…Much of the research on infant cortisol response has been on documenting normative patterns of maturation of the hypothalamic-pituitary-adrenocortical (HPA) system. To date, research by a number of investigators has led to significant contributions toward the understanding of the effects of environmental and birth conditions (Gunnar, Isensee, & Fust, 1987;Gunnar, Larson, Hertsgaard, Harris, & Brodersen, 1992;Larson, Gunnar & Hertsgaard, 1991), diurnal variation (Lewis & Thomas, 1990), and developmental changes (Gunnar, Broderson, Krueger, & Rigatuso, 1996;Lewis & Ramsay, 1995a;Ramsay & Lewis, 1994) on the infant's baseline cortisol and cortisol response to stress.…”

“…Much of the research on infant cortisol response has been on documenting normative patterns of maturation of the hypothalamic-pituitary-adrenocortical (HPA) system. To date, research by a number of investigators has led to significant contributions toward the understanding of the effects of environmental and birth conditions (Gunnar, Isensee, & Fust, 1987;Gunnar, Larson, Hertsgaard, Harris, & Brodersen, 1992;Larson, Gunnar & Hertsgaard, 1991), diurnal variation (Lewis & Thomas, 1990), and developmental changes (Gunnar, Broderson, Krueger, & Rigatuso, 1996;Lewis & Ramsay, 1995a;Ramsay & Lewis, 1994) on the infant's baseline cortisol and cortisol response to stress.Concurrently, developmental psychopathologists have focused on the association between certain types of psychopathology and individual differences in cortisol, both resting levels and reactivity. In some studies, low resting cortisol is associated with conduct problems whereas high resting cortisol is associated with depression and anxiety, with children with comorbid anxiety and conduct disorder having the highest resting cortisol (Granger, Stansbury, & Henker, 1994;McBurnett et al, 1991; McBurnett, Lahey, Rathouz, & Loeben, 2000).…”