Stress reactivity and attachment security.

Seventy-three 18-month-olds were tested in the Ainsworth Strange Situation. These children were a subset of 83 infants tested at 2, 4, 6, and 15 months during their well-baby examinations with inoculations. Salivary cortisol, behavioral distress, and maternal responsiveness measures obtained during these clinic visits were examined in relation to attachment classifications. In addition, parental report measures of the children's social fearfulness in the 2nd year of life were used to classify the children into high-fearful versus average- to low-fearful groups. In the 2nd year, the combination of high fearfulness and insecure versus secure attachment was associated with higher cortisol responses to both the clinic exam-inoculation situation and the Strange Situation. Thus, attachment security moderates the physiological consequences of fearful, inhibited temperament. Regarding the 2-, 4-, and 6-month data, later attachment security was related to greater maternal responsiveness and lower cortisol baselines. Neither cortisol nor behavioral reactivity to the inoculations predicted later attachment classifications. There was some suggestion, however, that at their 2-month checkup, infants who would later be classified as insecurely attached exhibited larger dissociations between the magnitude of their behavioral and hormonal response to the inoculations. Greater differences between internal (hormonal) and external (crying) responses were also negatively correlated with maternal responsiveness and positively correlated with pretest cortisol levels during these early months of life.