Examining degrees of stability in attachment throughout early childhood is important for understanding developmental pathways and for informing intervention. Updating and building upon all prior meta-analyses, this study aimed to determine levels of stability in all forms of attachment classifications across early childhood. Attachment stability was assessed between three developmental epochs within early childhood: infancy, toddlerhood, and preschool/early school. To ensure data homogeneity, only studies that assessed attachment with methods based on the strange situation procedure were included. Results indicate moderate levels of stability at both the four-way (secure, avoidant, resistant, and disorganised; κ = 0.23) and secure/insecure (r = 0.28) levels of assessment. Meta-regression analysis indicated security to be the most stable attachment organisation. This study also found evidence for publication bias, highlighting a preference for the publication of significant findings.

This paper provides a meta-analytic examination of strength and direction of association between parents' couple relationship quality and early childhood attachment security (5 years and under). A comprehensive search of four EBSCOhost databases, Informit, Web of Science, and grey literature yielded 24 studies meeting eligibility criteria. Heterogeneity of the couple quality construct and measurement was marked. To disaggregate potentially differentially acting factors, we grouped homogeneous studies, creating two predictor variables defined as "positive dyadic adjustment" and "inter-parental conflict". Associations of each construct with offspring attachment security were examined in two separate meta-analyses. Inter-parental conflict was inversely associated (8 studies, k = 17, r = -0.28, CI = [-0.39 to -0.18]), and dyadic adjustment was not associated with offspring attachment security (5 studies, k = 12, r = 0.14, CI = [-0.03 to 0.32]). The study supports finer distinctions of couple relationship constructs and measurement in developmental research, assessment, and intervention.