What research says about shared care and child wellbeing

The FHI 2022 systematic review

In November 2022, the Norwegian Institute of Public Health (FHI) published a systematic review for the Directorate for Children, Youth and Family Affairs (Bufdir) on custody and living arrangements after parental separation. The review synthesised 40 Nordic studies across three questions: the consequences of different arrangements for children, how children and parents experience them, and which factors shape outcomes.

The headline finding is that the review could not conclude that one arrangement is consistently better than another. Joint physical custody, primary residence with regular contact, and other shared-care patterns each had supportive evidence in some contexts and weaker evidence in others. Where one model appeared to do better in a single study, the broader picture across the 40 studies did not confirm it.

The review is publicly available on the FHI website and runs to around 200 pages including method tables. It is the most thorough Nordic synthesis currently available, and a reasonable starting point for parents or professionals looking for an evidence-based overview rather than individual studies cited in isolation.

Read the FHI 2022 review →

Why no single arrangement comes out ahead

Comparative studies from Sweden, Norway, and Denmark have looked at children in joint physical custody (shared residence with roughly equal time in each home), primary residence with regular contact, and primary residence with limited contact. The aggregate finding across this literature is that average differences between arrangements are smaller than the differences within each arrangement.

Two children in the same nominal arrangement can have very different experiences depending on the people, the household resources, and the level of conflict around them. The same schedule that works for one family does not necessarily work for another, and reviews of the literature increasingly frame the original question as ill-posed when separated from family context.

This does not mean schedules are unimportant. Practical factors such as proximity to school, the age of the child, and predictability of routines all matter, and the FHI review notes these consistently. What it does mean is that there is no defensible recommendation of any one model as a universal default.

Inter-parental conflict is the recurring variable

Across both qualitative and quantitative studies, the level and handling of inter-parental conflict appears repeatedly as a stronger predictor of child outcomes than the time-split itself. Where parents manage to coordinate practically and shield the child from disagreement, children in 50/50 arrangements and in primary-residence arrangements both do reasonably well. Where conflict is high, both arrangements become harder on the child.

This finding cuts in both directions. It cautions against assuming that a particular schedule will resolve a difficult dynamic between parents, and equally against assuming that a less equal schedule is automatically worse for the child. The schedule is one variable among several, and usually not the dominant one.

Researchers working in Scandinavia have suggested that the visibility and handling of disagreement may matter more than its absence. Families that do not always agree but keep the disagreement away from the child, and avoid using the child as messenger, produce outcomes closer to low-conflict families than to high-conflict ones.

The child's relationship with each parent

The second recurring finding is that the quality of the child's relationship with each parent predicts wellbeing more reliably than the precise number of nights at each home. A child with a warm and engaged relationship with both parents does well across a range of schedules, including week-on/week-off, 3-4-4-3, and arrangements that are not strictly equal.

Where one of the parent-child relationships is strained — through prolonged absence, conflict, or other difficulties — adjusting time alone rarely fixes the underlying issue. Schedule changes may be useful as part of a broader effort, but the literature does not support the idea that the right calendar can substitute for the relationship itself.

For practical purposes, this points away from accountancy. Parents tracking time down to the hour, or treating the calendar as the place where fairness is established, displace the more important variable — the day-to-day quality of contact — with the more measurable one.

Family preconditions and individual variation

The FHI review notes that family preconditions — each parent's mental and physical health, the household's financial situation, the practical distance between the two homes, and the child's own temperament — shape outcomes substantially. These are largely fixed at the point a separated couple is deciding on an arrangement, and they constrain what is realistically achievable.

The same review emphasises that children's experiences of identical arrangements vary considerably. A 7-7 schedule that suits a settled twelve-year-old may be too much movement for a sensitive six-year-old. A primary-residence arrangement that gives one child a stable base may feel restrictive to a teenager who wants more time with the other parent.

For professionals meeting separating families, the recurring recommendation in the literature is to work from the specific child and family in front of them rather than to apply a single model. This reflects the actual state of the evidence — not a methodological hedge, but the substantive finding of the research.

What this means for parents in practice

For parents reading the research themselves, the practical implication is to spend less energy choosing the "right" model and more on the variables the research identifies as load-bearing: handling disagreement well and sustaining a steady relationship with the child on both sides. The schedule should be workable for the household; beyond that, the choice between similar arrangements matters less than the writing on it usually suggests.

The coordination load itself is a recurring source of strain in shared-care families, and the literature treats it as one of the predictors of ongoing conflict between parents. Reducing it through structured written communication, pre-agreed parenting plans, and shared visibility of practical information is one of several strategies families use. Purpose-built coordination tools, including apps such as Lina, are one option among them.

The research does not provide a recipe. It points to a set of factors that recur across the literature and a strong caution against assuming that the schedule alone determines how a child fares. For families weighing options, the practical implication is to look at what is workable in their actual circumstances and to keep returning to the variables the evidence identifies as more important than the time-split: communication quality and the parent-child relationship.