Maternal Mirroring Predicts Positive Behavioral and Social-Cognitive Adjustment Beyond Infancy: Interactions with an Infant Carrying Intervention

Background and Purpose: Early mother-infant interactions are foundational for children's later developmental outcomes (Beebe et al., 2010; Lahtela et al., 2024). Maternal mirroring, a mother's contingent reflection of an infant's emotionally salient expressions, gestures, and vocalizations, has been linked to positive socioemotional outcomes, including emotional expressiveness and regulation, social expectancy, and attachment (Bigelow & Walden, 2009; Bigelow et al., 2018; Lavelli & Fogel, 2013; Legerstee & Varghese, 2001; Nicely et al., 1999). However, its developmental significance beyond infancy remains unclear, as few studies have examined whether early mirroring is linked to broader behavioral and social-cognitive adjustment. In addition, little is known about contextual factors that may shape its effects. Infant carrying, characterized by close physical proximity and high tactile contact, has been shown to enhance maternal responsiveness (Williams & Turner, 2020). As such, infant carrying is a caregiving behavior that may amplify the developmental impact of maternal mirroring.

This secondary analysis of a longitudinal randomized controlled trial of infant carrying assessed whether (1) maternal mirroring predicted children's behavioral and social-cognitive outcomes beyond infancy, (2) infant carrying was associated with mirroring, and (3) infant carrying moderated putative associations between mirroring and child outcomes.

Methods: Participants were young mothers (M=19.3 years, SD=2.3), randomly assigned to an intervention (infant carrying, n=34) or control (book reading, n=33) condition. Mothers and children completed four in-home assessments at 3 weeks (Wave 1), 4 months (Wave 2), 7 months (Wave 3), and 3.5 years (Wave 4) postpartum. Maternal mirroring was assessed during the Still-Face Paradigm (Tronick, et al., 1978) at Wave 3. Preschool outcomes at Wave 4 included child behavioral problems measured on the Child Behavior Checklist (CBCL/1.5-5; Achenbach & Rescorla, 2000); empathy assessed on the Early Childhood Empathy Questionnaire (EmQue; Rieffe et al., 2010); and narrative characteristics coded from story stems using the Attachment-Focused Coding System (AFCS; Splaun et al., 2010) from the MacArthur Story Stem Battery. Narrative coherence was operationalized as a composite of AFCS emotion dysregulation, avoidance of themes and emotions, and resolution of themes (reversed). Prospective associations were examined using multiple linear regression with interaction terms testing moderation by intervention condition. Significant interaction terms were probed as conditional effects and visualized using simple slopes.

Results: Maternal mirroring did not differ between intervention and control conditions, t(31)=0.725, p=0.47. Greater mirroring predicted significantly better child adjustment across CBCL measures, including lower internalizing [β(95% CI)=-1.047(-1.463, -0.631), p<0.001], externalizing [β(95% CI)=-0.702(-1.182, -0.221), p=0.004], and emotional reactivity [β(95% CI)=-0.762(-1.270, -0.255), p=0.003], with comparable effects across conditions. In contrast, significant interaction effects emerged for narrative coherence [b(95% CI)=0.075(0.016, 0.133), p=0.012] and empathy [b(95% CI)=0.020(0.003, 0.037), p=0.022]. Specifically, higher maternal mirroring predicted greater narrative coherence [b(95% CI)=0.035(0.009, 0.061), p=0.009] and higher empathy [b(95% CI)=0.011(0.002, 0.020), p=0.014] in the intervention group, but not in controls.

Conclusion and Implications: These findings indicate that maternal mirroring has enduring benefits for positive behavioral and socioemotional adjustment beyond infancy. Moreover, infant carrying is an accessible, cross-cultural intervention that may amplify the positive effects of maternal mirroring on children's social-cognitive capacities, including empathy and narrative coherence.