Attachment status and mother-preschooler parasympathetic response to the strange situation procedure

Background: Early attachment relationships are important for children's development of behavioral and physiological regulation strategies. Parasympathetic nervous system activity, indexed by respiratory sinus arrhythmia (RSA), is a key indicator of self-regulation, with links to numerous developmental outcomes. Attachment-related changes in and associations between mother and child RSA during the Strange Situation procedure (SSP) can elucidate individual differences in physiological response to stress that are important for understanding the development of and intervention for psychopathology. Methods: A sample of 142 at-risk mothers and preschool-age children participated in the SSP and provided time-synchronized RSA data during the 7 episodes, which included 2 separations and 2 reunions. Attachment classifications were obtained using the Cassidy et al. (1992) coding system. Linear mixed-effects models were constructed to examine attachment-related change in RSA during the SSP and the concordance between mother and child RSA over time. Results: Findings demonstrated attachment-related differences in children's RSA. Secure children's RSA was relatively stable over time, whereas insecure-avoidant children showed RSA increases during the first separation and insecure-resistant children's RSA declined across the SSP. Mothers showed RSA withdrawal during separation regardless of child's attachment classification. Mother-child RSA showed a positive concordance that was strongest in the insecure-resistant group, compared with the other groups. Conclusions: Results support attachment theories concerning parasympathetic response to stress and the role of the mother-child relationship in physiological regulation. Our findings advance previous research by focusing on at-risk mother-preschooler dyads within diverse attachment classifications.