Investigating Infant Crying Persistence and Cry Acoustic Features as Early Risk Indicators for Social Adjustment: Developmental Associations with Infant Vagal Tone and Attachment Stress Public Deposited

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  • March 21, 2019
  • Kolacz, Jacek
    • Affiliation: College of Arts and Sciences, Department of Psychology and Neuroscience
  • The present pair of studies used hypotheses derived from the Polyvagal Theory (Porges, 2007; 2011) to assess the capacity of infant crying persistence and cry acoustic features to predict social adjustment in toddlerhood, and to elucidate the mechanisms that account for this relation. In view of this theoretical framework, behavioral cry frequency and acoustic features may serve as early markers of the functioning of the neural social engagement system. Importantly, this system integrates the regulation of bodily states, such as cardiac regulation via the vagus nerve, with aspects of social communication such as expressivity in the voice and eyes and the capacity to extract human voices from background noise. Both studies used data from a longitudinal sample of ethnically and economically diverse families with children that were followed from 3 months to 24 months of age. Crying persistence was measured using daily cry diaries at 3 months and retrospective reports. Cardiac vagal tone was indexed using respiratory sinus arrhythmia (RSA). Children’s social adjustment was measured by parent reports and observations made in the laboratory. The first study (n = 391) tested a biopsychosocial model of the relation between infant crying and social adjustment as accounted for through two possible paths: the stress imposed on caregivers by persistent crying, and infant vagal activity in free play with the mother at 6 months. Results showed that infant crying persistence negatively predicted social relatedness in toddlerhood and crying persistence was related to higher parent-reported attachment stress which predicted poorer social relatedness. Crying persistence in infancy did not predict vagal tone in infancy and toddlerhood, but higher vagal tone placed children at risk of poorer social relatedness. A second study, based on a subset of the overall study sample (n = 37), assessed infant cries for mean fundamental frequency and its variability, as well as overall cry modulation depth. More smoothly-modulated cries were related to higher RSA during the cry bout as well as higher RSA during a free-play parent-child interaction at 6 months. Behaviorally, children who avoided a stranger in the lab at 24 months had more unstable cries as infants. The results of this pair of studies suggests that infant cry persistence and acoustic cry features may be promising early indices of the developing social engagement system. Examining these cry characteristics at a time when the social behavioral repertoire is still nascent and it organization highly sensitive to the quality of the social context presents a promising new avenue for prospective research on social development.
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  • In Copyright
  • Bollen, Kenneth
  • Gariépy, Jean-Louis
  • Cox, Martha
  • Kurtz-Costes, Beth
  • Lewis, Gregory
  • Doctor of Philosophy
Degree granting institution
  • University of North Carolina at Chapel Hill Graduate School
Graduation year
  • 2016

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