RT Journal Article SR 00 ID 10.1017/S0954579421001310 A1 Volling, Brenda L. A1 Oh, Wonjung A1 Gonzalez, Richard A1 Bader, Lauren A1 Tan, Lin A1 Rosenberg, Lauren T1 Changes in children’s attachment security to mother and father after the birth of a sibling: Risk and resilience in the family JF Development and Psychopathology YR 2023 FD 2023-08 VO vol. 35 IS n° 3 SP 1404 OP 1420 AB Changes in children’s attachment security to mother and father were examined for 230 firstborn children (M = 31.17 months), their mothers and fathers participating in a longitudinal investigation starting in the last trimester of the mothers’ pregnancy and 1, 4, 8, and 12 months after the birth of an infant sibling. Both parents completed the Attachment Q-set at prenatal, 4, and 12 months. Growth mixture models revealed four latent classes in which children’s attachments were (a) both secure with a modest decline to both parents (68.3%); (b) more secure with father than mother with a steep decline for both (12.6%); (c) both insecure with no change (10%); and (d) more secure with mother than father with a modest increase for both (9.1%). Multi-group latent growth curve analyses revealed that parenting and coparenting differed across families. Children had lower externalizing behavior problems in families with two secure attachments than in families with one secure attachment, either to mother or to father, who, in turn, had fewer problems than children with two insecure attachments. Findings underscore the strengths of a family systems framework to understand attachment relationships with multiple caregivers and the family risks and protective factors that covary with children’s behavioral adjustment after the birth of a sibling. PB Cambridge University Press SN 0954-5794 LK https://publications.ut-capitole.fr/id/eprint/42897/ UL http://iast.fr/pub/123551