An Examination of Sibling Co-Placement and Internalizing and Externalizing Behavior Among Youth in Foster Care

Background and Purpose. Placing foster siblings together in foster homes, known as sibling co-placement, is generally understood as contributing to siblings’ positive development. When siblings in care are placed together, they can be less likely to exhibit trauma symptoms and anxiety, while being more likely to experience strong emotional support and close bonds with each other (Hillman et al., 2022; Seale & Damiani-Taraba, 2018). However, the extant literature has lacked a nuanced understanding of how sibling co-placement in foster care informs various behavior problems of older and younger siblings. This study seeks to address this gap by investigating a range of behavior problems among siblings who were co-placed vs. those who were not co-placed.

Methods. The secondary investigation utilized cross-sectional data from Supporting Siblings in Foster Care (SIBS-FC), the first large-scale randomized clinical trial to evaluate a sibling relationship development intervention for foster youth. 328 youth drawn from a metropolitan Pacific Northwestern region were included in the analysis, reflecting older (n=164, averaging 13.1 years) and younger siblings (n=164, averaging 10.7 years). The majority of the sample (72%) lived together (coded=0), while 28% lived apart (coded=1). The behavior problem measurements reflected the Child Behavior Checklist (CBCL), which has 8 subscales: anxious/depressed, withdrawn, somatic complaints, social problems, thought problems, attention problems, rule breaking, and aggressive behavior. Internalizing problems included anxious/depressed, withdrawn, and somatic complaints, while externalizing problems included rule breaking, and aggressive behavior. CBCLs were collected by trained assessors who asked foster parents to describe the behaviors of siblings. To assess the impact of sibling co-placement on behavior problems, path analysis was employed, estimated via bootstrapping. Age, gender, and race were included as covariates.

Results. Among older siblings, sibling co-placement was significantly associated with fewer internalizing (B=3.389, SE=1.711, b=.178, p=.048) and fewer externalizing problems (B=5.220, SE=2.349, b=.181, p=.026). However, among younger siblings, no significant differences were found in internalizing (B=2.529, SE=1.527, b=.134, p=.098) or externalizing (B=-2.064, SE=1.986, b=-.082, p=.299) problems. When examining CBCL subscales, sibling co-placement among older siblings showed significant associations with withdrawn (B=1.113, SE=.551, b=.169, p=.044) and rule breaking (B=2.530, SE=.968, b=.209, p=.009) behaviors; a marginally significant association was identified with attention problems (B=1.588, SE=.818, b=.140, p=.052). Conversely, among younger siblings, only somatic complaints (B=1.029, SE=.502, b=.174, p=.041) were significantly associated with sibling co-placement. For both older and younger siblings, anxious/depressed, social problems, thought problems, and aggressive behavior were not significantly associated with co-placement.

Conclusions and Implications. This study highlights the importance of sibling co-placement and the necessity of different approaches to addressing behavior problems among older and younger siblings in foster care. The findings highlight that older siblings who live together with their siblings can display fewer internalizing and externalizing problems as compared to those who are placed separately. The study emphasizes the need for child welfare researchers to recognize developmental differences in the mental and behavioral health trajectories of older vs. younger siblings in care, and for practitioners to tailor practice and policy around the developmental needs of older and younger siblings.