Getting Custody Arrangements Right

Children need different things from each parent at different stages of development.

By Erica Komisar

Photo: Getty Images

For most of the 20th century, American family courts operated on the assumption that children belong with their mothers. The “tender years doctrine” shaped divorce law for decades, often needlessly severing fathers from their children’s lives during formative years of development. By the 1990s most states had formally abandoned it, replacing it with a “best interests of the child” standard. It was gender-neutral in name, if not always in practice.

Today, courts across the country have moved aggressively toward a presumption of 50/50 shared custody—equal time, equal access, equal everything. The intent is fairness. The problem is that fairness to adults and developmental soundness for children aren’t always the same thing. In the rush to correct one mistake, we may be making another.

Developmental science tells a more nuanced story than either “children need their mothers” or “parents are interchangeable.” Children actually need different things from each parent at different stages. Custody arrangements that ignore developmental timing can cause real neurological harm, regardless of which parent gets shortchanged.

In the first three years of life, the brain learns emotional regulation, primarily through the attachment relationship with a primary caregiver. This is the person who soothes the child in distress, responds consistently to his needs and serves as what attachment theorist John Bowlby called a “safe harbor.” When young children are separated from that figure for extended periods, cortisol levels spike in the developing brain. Chronic early stress of this kind causes short-term distress and reshapes the stress-response system itself, which can create consequences that echo for decades.

Mothers are more likely to be that primary attachment figure in early life, partly due to breast-feeding and co-sleeping, and partly because oxytocin, the hormone that drives sensitive and attuned caregiving, surges more intensely in mothers during birth and early caregiving. But this isn’t a universal rule. When a father has been the primary caregiver, the one who wakes at night and soothes the baby through the day, then separating that child from his father for extended periods is equally harmful. Attachment follows presence, not gender.

Fathers aren’t simply backup mothers. Their role in early development is distinct and irreplaceable: physical play, stimulation, roughhousing, the kind of exciting and slightly unpredictable engagement that builds resilience and teaches children to regulate arousal. This contribution is essential. It’s also different from what a distressed infant needs at 2 a.m. A rigid 50/50 split that removes a young child from his primary attachment figure for days at a time, in the name of equality, doesn’t serve that child.

As children grow, their needs shift. By middle childhood, roughly ages 5 to 12, the picture changes. Children in these years have stronger emotional resources and a greater capacity to make meaning of their circumstances. This is the most neurologically stable window for managing family transitions, and the period when practical shared parenting is most feasible and beneficial. Fathers who were less central in the earliest years become equal partners during this stretch.

Adolescence is another layer of complexity. Between 9 and 18, the brain undergoes a second major reorganization, pruning neural pathways and rewiring for adult life, while teenagers simultaneously navigate identity, social pressure and a nervous system under reconstruction. What adolescents need most is stability and at least one home base that feels secure. The particulars of the custody split matter less than the consistency and quality of each parent’s relationship with the child.

The courts’ turn toward 50/50 was a necessary correction to a system that had minimized fathers. Fathers matter enormously, not as supplements to maternal care, but as essential figures whose specific kind of engagement shapes children in ways nothing else replicates. The goal should never be to push fathers to the margins. But the solution to one overcorrection can’t be another. Children don’t need custody arrangements built around adult ideas of fairness. Rather, they should be built around a simple question: What does a particular child need, at each stage of development, from each of his parents?

Ms. Komisar is a psychoanalyst and author of “The Parent’s Guide to Divorce.”