A global review of 60 studies challenges the claim that joint physical custody reduces the effect of divorce on child development only in low-conflict situations.

When verbal conflict between separated parents is high, which type of custody is more likely to ameliorate the effect of divorce on child development: joint physical custody (JPC), meaning that the child lives with each parent at least 35% of the time, or single physical custody (SPC)? Is JPC beneficial only when the parents have a low-conflict, cooperative relationship?

Linda Nielsen, professor of educational and adolescent psychology at Wake Forest University in the USA, examined this key question. Her review of 60 studies challenges the widely circulated claim that JPC ameliorates the effect of divorce on child development only in low-conflict situations (e.g. Richard Emery’s book, Two homes: One Childhood-a parenting plan to last a lifetime in 2016). The 60 studies cover children of all ages, from infants to young adults, with sample sizes ranging from 21 to 51,802, in eight countries. Fifty-three of the research articles were published in peer-reviewed journals, and seven were published by the Australian government.

The studies looked at five child development outcomes:

  • Academic/cognitive – e.g. grades, attentiveness in class, cognitive development
  • Emotional/psychological – e.g. depression, anxiety, low-self-esteem
  • Behavioral – e.g. hyperactivity, smoking, alcohol, drugs
  • Physical – e.g. sleep, headaches, digestion
  • Quality of parent-child relationships.

Nineteen of the 60 studies statistically analysed how parental conflict affects child development. Sixteen of those studies found that even when the analysis controls for conflict, children whose parents shared custody had the same or better outcomes on all measures. Put another way: if children in families with similar levels of conflict are compared, JPC children do as well as or better than SPC children. The other three studies found that JPC children had better or equal outcomes on all measures but one.

When parents had JPC even though one parent initially opposed it, the JPC children still had equal or better outcomes than SPC children.

Six of the 60 studies identified particular circumstances in which the effect of divorce on child development among JPC children is, on average, worse than for SPC children:

  • Adolescents in high-conflict families who have a poor relationship with one of the parents
  • Teenage girls whose parents had high conflict eight years after separating
  • Adolescents who are highly conscientious or extremely extroverted.

High conflict in itself does in fact worsen the effect of divorce on child development. But these studies found that even when high conflict is high, JPC children have equal or better outcomes than SPC children.

Is the effect of divorce on child development less in JPC children because their parents are better at parenting?

Nine of the 60 studies looked at the quality of child-parent relationships, examining whether the divorce has a milder effect on child development in JPC families because the children and parents have better relationships and because the parents have better parenting skills? Five of the nine found that even when controlling for parent-child relationships, children did as well or better in JPC families on all measures. In two studies, children did worse on one measure and better/equally on all the others.

Is the effect of divorce on child development less in JPC children because their parents are wealthier?

Twenty-five other studies looked at family income to examine whether JPC children have better outcomes because their parents are better off. Again, the answer is no. Twenty-three studies found that when controlling for income, JPC children do as well or better on all measures; in two studies, JPC children did better or the same on all measures but one.

The importance of family relationships in mitigating the effect of divorce on child development

Overall, joint physical custody is linked to less harm to child development from divorce independently of parenting factors, family income and level of conflict between the parents.