| Abstract: | Emotional reactivity is an important dimension thought to underlie individual differences in infant temperament. In a series of studies, we have examined the relation between behaviors reflecting this dimension and measures of heart rate variability. In the current study, longitudinal behavioral data on two groups of infants selected for their pattern of heart period variability are presented: those with high vagal tone (high heart rate variability) and those with low vagal tone (low heart rate variability) at 14 months of age. The data suggest that infants with high vagal tone were more reactive to both positive and negative events at 5 months and more sociable and approachful at 14 months. Infant reactivity to mildly stressful events seems to be a stable dimension during the first year, and there is a strong association between differences in reactivity and the degree to which the autonomic nervous system is influenced by vagal tone. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
