Emotional Responses of Down Syndrome and Normal Infants in the Strange Situation. The Organization of Affective Behavior in Infants

The quality of separation distress of 26 19-month-old Down syndrome infants observed in the Strange Situation was compared with that of 43 normal infants who were observed at 121/2 and 191/2 months to assess whether Down syndrome infants responded more similarly to cognitively comparable normals than to age-comparable normals. Time-sampled ratings of facial and vocal expressions yielded summary measures of peak distress intensity and emotional range for each episode, latency to distress onset and rise time to peak intensity during separation episodes, recovery time (i.e., soothing) during reunions, and emotional lability for the entire assessment. For both expressive modalities, Down syndrome infants evinced less intense separation distress, longer latencies to onset, briefer recoveries, and a diminished range and lability of responding in comparison with normals at each age. These group differences were predicted in light of the cognitive and physiological characteristics of Down syndrome. Despite these differences, the organization of response parameters was highly similar for Down syndrome and normal children: Distress intensity was negatively correlated with onset latency and positively correlated with recovery time. Analysis of emotion-attachment interrelations revealed that distress intensity was consistently associated with a contact-maintenance versus distance interaction dimension of mother-directed behaviors for each group. Taken together, these findings reflect group differences in the quality of emotionality but a consistent organization underlying this aspect of socioemotional responsiveness.