Child-Led Emotion Regulation Behaviours during Toddler Vaccinations: Building Understanding through a Dyadic Lens

Vaccination of infants and young children is a routine procedure requiring regulation of high distress. While infants rely heavily on their caregivers for regulating distress, in toddlerhood, children begin to build a repertoire of their own emotion regulation (ER) skills to modulate their distress. The current dissertation consists of three studies to better understand toddler-led ER during vaccination. Study 1 is a published systematic review and meta-analysis (Gennis et al., 2022) aimed at understanding the concurrent relationships between child-led ER behaviours and distress in the first three years of life. Findings indicated that disengagement of attention and physical self-soothing strategies were typically regulatory (i.e., had negative relationships with distress), whereas parent-focused behaviours (e.g., orienting to the caregiver) were associated with more distress, suggesting a signalling function to gain support. With the exception of physical self-soothing, which showed a clear negative association in the first year, relationships between regulatory behaviours and distress were strongest in the second year. Study 2 (Gennis, Flora, Norton et al., submitted) used auto-regressive cross-lagged models to assess the concurrent and predictive relationships between three child-led ER behaviour clusters (disengagement of attention, physical self-soothing, and parent-focused behaviours) and pain-related distress responses during 12- and 18-month vaccinations. Findings indicated that disengagement of attention and physical self-soothing generally had negative relationships with pain-related distress, suggesting a possible regulatory role, whereas parent-focused behaviours were related to higher pain-related distress, suggesting a signalling role for parent support. With the exception of physical self-soothing, relationships were generally stronger at 18 months. Study 3 (Gennis, Flora, McMurtry, et al., submitted) used growth curve modelling to understand the associations between child-led ER behaviours and the change in pain scores across the appointment (regulation) at 12- and 18- months, after accounting for parent regulatory behaviours and pre-needle distress. Pre-needle distress consistently predicted regulation and parent regulatory behaviours played an increasing role in older toddlers. Findings suggest that after accounting for pre-needle distress and parent regulatory behaviours, child-led parent-focused behaviours predicted less regulation post-needle. Children seek their parent when they are struggling to regulate, suggesting continued need to understand vaccination as a dyadic context.