Comparative Study of Preserving Sibling Cohabitation in Custody Disputes in French, United States, and Iranian Legal Systems

Introduction 
Although sibling relationships constitute one of the most significant determinants of children’s development, in many jurisdictions the traditional orientation of family law in post-separation custody arrangements has primarily been directed toward regulating the relationship between parents and each child, with the preservation of sibling ties frequently overlooked by legislators. Yet, in contexts of family disruption, sustaining sibling relationships may alleviate, at least in part, the hardship and adverse consequences of parental separation. The significance and protective potential of sibling bonds have progressively prompted legal systems to acknowledge the necessity of safeguarding such relationships, such that the historical neglect of siblings within family law is gradually being redressed. The emergence and consolidation of the “best interests of the child” principle, as embodied in Article 3 of the UN Convention on the Rights of the Child, has undoubtedly played a central role in this shift of perspective. Against this backdrop, the present article examines and comparatively analyses the legal frameworks governing the preservation of sibling co-residence in custody disputes in the legal systems of France, the United States, and Iran.
Methods
The present study employs a doctrinal and descriptive–analytical method, conducted through a qualitative approach and based on the collection of data from library and documentary sources. To this end, in addition to relying on authoritative scholarly materials within each of the legal systems examined, the study also explores recent legislative developments and the practical application of legal rules through the analysis of judicial decisions, so that the inquiry does not remain confined to black-letter law. In Iranian law, alongside reference to certain jurisprudential dimensions of the subject and recent legislative developments, particular emphasis is placed on judicial practice; accordingly, selected decisions are examined and interpreted with a focus on the manner in which judges invoke the best interests of the child to safeguard co-residence among siblings. Furthermore, the study is structured on a comparative basis and, by juxtaposing the three legal systems under consideration, seeks to assess the position of each system in relation to the others in addressing the preservation of sibling relationships in custody disputes. Finally, relying on the doctrinal and comparative findings, the study advances proposals aimed at improving and strengthening the custody rules in Iranian law.
Results and discussions
This study demonstrates that, across the three legal systems under examination, the capacity to protect the co-residence of siblings in custody disputes exists, albeit to varying degrees and through distinct institutional mechanisms. In French law, the legislature institutionalized the principle of “non-separation of siblings” in 1996 through Article 371-5 of the Civil Code. On the basis of this principle, the separation of siblings is permissible only where co-residence is impossible or incompatible with the child’s best interests. Protection of sibling relationships in France is not confined to the field of custody; it also extends to domains such as adoption, placement in educational institutions, and social welfare arrangements. Accordingly, in this legal order, preserving sibling co-residence upon parental separation rests on a statutory foundation. That said, the principle is rebuttable, and the judge may depart from it, where duly justified by considerations relating to the child’s interests, such as specific therapeutic or educational needs or severe incompatibilities. In the law of the United States, the issue of sibling co-residence following parental divorce is typically addressed within the framework of “split custody.” Under this arrangement, each parent assumes physical custody of one or more children individually, while custody of the remaining child or children is allocated to the other parent. In recent years, sensitivity toward maintaining sibling co-residence has likewise increased within this system. Although split custody, particularly where the parents so agree, is accepted in certain cases, in many states the separation of siblings is regarded as exceptional, and orders to this effect require compelling justification. The states, however, are not uniform in the degree and mode of protection afforded to sibling co-residence: some have established a formal presumption against separation, whereas in others judges prevent the division of siblings through the interpretation of the child's best interest standard. In Iranian law, although no explicit rule has been enacted concerning the continuity of sibling co-residence following parental divorce, recognition of the “best interests of the child” in the Note to Article 1169 of the Civil Code and Article 45 of the Family Protection Act has created an important legal basis in this regard. On this foundation, the judge may, upon establishing that it is in the child’s interest, refrain from separating siblings and consolidate their custody with a single parent, particularly where co-residence contributes to their emotional well-being, psychological stability, and social development. This approach is also consistent with the jurisprudential foundations of custody under Islamic law. A review of judicial practice indicates that the best interests principle has, in fact, been invoked by certain thoughtful and holistic-minded judges in order to preserve sibling co-residence. Moreover, Article 29 of the Family Protection Act has introduced an additional mechanism enabling the establishment of visitation rights between siblings in cases of separated custody, an innovation that merits greater judicial attention.
conclusion 
the shared emphasis on preserving sibling co-residence in custody disputes reflects the emergence of a convergent understanding of the child’s best interests across different legal systems and may serve as a foundation for the further development of comparative research and the utilization of other jurisdictions’ experiences. In other words, by relying on the existing practical convergences among the three legal systems, the present study, moving beyond purely case-based analysis and with a methodological reflection, argues that comparative legal studies, at least within certain domains of family law, may be regarded as both legitimate and fruitful. This study recommends that the Iranian legislature, consistent with the practice of certain other jurisdictions, identify, on an illustrative basis, the principal factors for assessing the child’s best interests in custody disputes, and that this list expressly include the preservation of meaningful contact and effective interaction with siblings. In such cases, the judge should weigh each factor, including sibling co-residence, in light of the best interests principle and the interaction of the remaining considerations, and render a decision that secures the greatest attainable benefit for each child.