A relatively recent study of foster placements found that children placed with at least one sibling had more stability than children placed alone. The research looked at more than 2500 children placed in foster care in Allegheny County, Pennsylvania from 2015 to 2019. Like all such studies, its geographic limitations may limit its application to other parts of the country, but it does follow in a long line of similar research reaching similar conclusions.
One interesting finding is that while children placed with at least one sibling had better stability, the trend did not hold true when all siblings were placed together. People who work in foster care know that it is extremely difficult to find placements for large sibling groups. According to the authors of this study, “This may suggest that, when all members of a sibling group cannot be placed together, the benefits of placing each child with at least one sibling may provide similar benefits.”