Child, Youth, and Family Studies, Department of


Date of this Version



Monographs of the Society for Research in Child Development 82:3 (September 2017), pp. 93–105.

doi: 10.1111/mono.12313


Copyright © 2017 Society for Research in Child Development, Inc.; published by Wiley. Used by permission.


Emotional reactivity in this chapter refers to children’s moodiness, worrying, emotional instability, and their inability to emotionally cope with new situations (Achenbach & Rescorla, 2000) rather than a temperamental characteristic. Emotionally reactive children often have difficulties adapting to change and are described as moody and anxious. Because the birth of a sibling is considered a significant change within the family, emotionally reactive children may become increasingly emotionally labile after the birth. During the transition to siblinghood, Stewart (1990) reported that children experienced an increase in emotional intensity, a decrease in the range of mood expressions, and an increased tendency to approach rather than withdraw from social interaction in the year following the infant’s birth. The likelihood of whether children have problems with emotional reactivity after the sibling’s birth was contingent on whether children were described by mothers as emotionally reactive prior to the birth. Dunn and Kendrick (1982) reported that emotionally reactive children prior to the birth were either emotionally reactive after the birth or actually increased in emotional reactivity in the first 8 months following the sibling’s birth. These findings provide support for the accentuation principle, where life stressors accentuate the individual’s preexisting psychological traits prior to the life event, in this case, the birth of an infant sibling (Elder & Caspi, 1988; Volling, 2012). Dunn and Kendrick (1982) argued that the change in children’s miserable moods and worrying was not simply a matter of age-related developmental change because these behaviors increased only from one month before the birth to 8 months after, and not from 8 to 14 months, when the family had already adjusted to the birth. Thus, there is some evidence to suggest that we might see an adjustment and adaptation response for children’s emotional reactivity, with an immediate increase in emotional reactivity that either declines or stabilizes shortly afterward.

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In sum, the trajectories of children’s emotional reactivity revealed that there are relatively stable patterns of behavior over the transition and that children high on emotional reactivity prior to the birth of a sibling were also relatively high afterward. The vast majority of children fell into a low-stable class well within a normative, nonclinical range of behavior, suggesting that most children have few to no emotional reactivity difficulties in response to the impending birth of their infant sibling. Children, whose mothers were more stressed and hassled about parenting responsibilities prenatally, were more emotionally reactive and actually increased in their emotional reactivity after the birth of a sibling. These findings underscore the fact that parenting stresses (with the firstborn) experienced by mothers during the pregnancy with the second-born may set in motion a family dynamic that gives rise to increased emotional reactivity before and after the birth. It is also possible that emotionally reactive children create additional burdens and stresses for parents. No doubt the process is probably bidirectional, with emotionally reactive children creating more parenting stress, which, in turn, contributes to children’s feelings of emotional insecurity, worrying, and reactivity over time, and future work would be well advised to consider investigating these developmental processes.

Children with better emotional understanding before the birth were also more likely to be emotionally reactive and increase in their emotional reactivity over time (i.e., mid-increasing) than children in the low-stable class. Because children with better emotional understanding are more prone to emotional problems through an over-internalization of others’ and one’s own distress (Keenan & Shaw, 1997), perhaps children with better emotional understanding are more attuned to the emotional climate of the family and are better able to comprehend the impending changes that accompany the birth of a sibling. Finally, children in the high-stable class of emotional reactivity were not only characterized by greater negative emotionality, but were also at-risk for developing conflictual interactions with their siblings 1 year after the birth, which is not surprising given prior research finding that children high in negative emotionality are more involved in sibling conflict and have higher internalizing and externalizing behavior problems (Dirks et al., 2015). Given the predictive utility of early sibling conflict for later sibling conflict (Dunn et al., 1994), and the links between sibling conflict and other negative developmental outcomes for children and adolescents (e.g., externalizing and internalizing problems; Buist et al., 2013), these highly emotionally reactive children, although few in number, may be potentially at-risk for later developmental difficulties.