The Evidence For Equal Custody Time Sharing

Where We Are and Where We Should Be On Parental Custody In Divorce and Paternity Cases

Florida family law has made decent progress towards recognizing that both divorced parents should be involved in the rearing of their children.  However, here we will show evidence to parents, state legislators, judges and the governor that the full benefit of time sharing can only be achieved when practicing equal or close to equal time sharing of child custody between divorced parents.

This is a summary of how we propose to change Florida family laws to take advantage of what we know from this evidence:

We propose that when a divorce or paternity case reaches the trial stage (because the mediation failed to achieve an agreement on the terms of the divorce) the law should instruct the family court judges to treat near equal time sharing (minimum of 45%-55%) as a rebuttable presumption.  This means that the burden of proof to deviate from this time sharing method is on those who propose it.  This proposal does not affect agreements reached during the mediation state.  However, we highly recommend to parents in divorce and paternity cases to reach agreements that provide an equal or near equal distribution of the custody time.  The evidence below shows that this is good for the children's development and, at least, does not harm the relationship between the parents.

The Evidence Favoring Equal Time Sharing

This first of a series of articles supporting equal time sharing is about the extensive and overwhelming evidence for the benefits children of divorced parents get from shared parental custody. It is extensive because of the large volume of academic articles written on the subject.  These studies overwhelmingly agree that the healthy psychological development of children of divorced parents is greater when physical custody is shared.  And the studies with the more sophisticated analysis show that this healthy development increases in proportion to how close to 50-50 is the time sharing arrangement.  Here are summaries of some of these studies. 

(1) Joint Versus Sole Physical Custody: Children’s Outcomes independent of Parent Child Relationships, Income and Conflict in 60  Studies, By Dr. Linda Nielsen, Wake Forest University, June 2018

Dr. Linda Nielsen, professor of Adolescent and Educational Psychology, has written a review of sixty studies on comparing children’s outcomes in shared to those in sole physical custody families, independently of family income and parental conflict. The shared children had better outcomes in almost all the studies. Her papers are available upon request (

In her sixty studies, shared parenting or “joint physical custody” (JPC)  means that the children live with each parent at least 35% and usually 50% of the time.

The measures of the children's outcomes of well-being in the sixty studies included: academic achievement, emotional health (anxiety, depression, self-esteem, life satisfaction), behavioral problems (delinquency, school misbehavior, bullying, drugs, alcohol, smoking), physical health and stress-related illnesses, and relationships with parents, stepparents, and grandparents.

Nielsen's conclusions are:
  • Children in joint physical custody (JPC) had better outcomes than than those in sole physical custody (SPC), excluding situations in which children needed protection from an abusive or negligent parent, even before their parents separated.
  • Infants and toddlers in JPC families have no worse outcomes than those in SPC families.
  • JPC children had better outcomes across multiple measures of well-being when the level of parental conflict, family income and quality of co-parenting relationships were factored in.  
  • JPC children still had better outcomes than SPC children even though most JPC parents did not originally mutually or voluntarily agree to the plan. They had to compromise at mediation or obey a court order.
  • Being involved in high, ongoing conflict is no more damaging to children in JPC than in SPC families.
  • JPC families appear to reduce the children's added stress, anxiety and depression caused by high parental conflict and poor co-parenting. 
  • JPC parents are more likely to have detached, distant and “parallel” parenting relationships than to have “co-parenting” relationships where they work closely together, communicate often, interact regularly, coordinate household rules and routines, or try to parent with the same parenting style.
  • No study has shown that children whose parents are in high legal conflict or who take their time sharing dispute to court have worse outcomes than children whose parents have less legal conflict and no time sharing hearing.
(2) Parenting Time, Parent Conflict, Parent-Child Relationships, and Children's Physical Health, by William V. Fabricius, Priscila    Diaz and Sanford L. Braver, 2010

This study uses a statistical model relating percent of time spent with each parent to the children's outcomes.  It finds that the best outcomes are achieved when the time spent is 50-50.   This is clear from the following quotes from the article:

“The father-child relationship improved with each increment of PT from 0% time with father to 50%”

“the long-term mother-child relationship mirrored the father-child relationship: i.e., it remained constant with each increment of PT from 0% to 50%,and declined thereafter.”

“These findings indicate that when either parent has the child living with him or her for a majority of the time, increasing PT [parental time] with the second parent is not associated with any risk of harm to the relationship with the first parent. Instead, increasing PT with the second parent is associated with improvements in that relationship, and benefits continue to accrue up to and including equal PT.  At 50% PT it appears that each relationship achieves its highest level of emotional security.”

In addition, the article concludes that children under these arrangements perceive less conflict among their parents than those who have a primary residential parent. Even when equal time-sharing parents remain in a high-conflict relationship, their children do not suffer most of the negative effects of their contentiousness.

(3) Child Adjustment in Joint-Custody Versus Sole-Custody Arrangements: A Meta-Analytic Review, by Robert Bauserman, 2002

In a review of 33 studies published between 1982 and 1999, children of parents who had joint physical custody fared much better than children who lived primarily with their mothers Even after controlling for the level of conflict between the parents, these children were doing much better emotionally, academically, psychologically and socially.

(4) Social Science and Parenting Plans for Young Children: A Consensus Report, Richard A. Warshak, 2014

Based on the research, 110 international experts came to the consensus that joint physical custody is in childrens’ best interests, even for the youngest children with the exception of children who would need protection from negligent, abusive or unfit parents.  


The social sciences fall on the side of equal time-sharing.  Legislators and family court judges should start recognizing this.

By Orlando Family Law Attorney Eduardo J. Mejias, Practicing Family Law Only Since 2011

Bibliographical Notes

(1) Nielsen:

Linda Nielsen (2018) Joint Versus Sole Physical Custody: Children’s Outcomes
Independent of Parent–Child Relationships, Income, and Conflict in 60 Studies, Journal of Divorce
& Remarriage, 59:4, 247-281, DOI: 10.1080/10502556.2018.1454204
Copies of her original studies can be obtained from 
(2) Fabricus:

Parenting Time, Parent Conflict, Parent-Child Relationships, and Children's Physical Healh, by William V. Fabricius, Priscila Diaz, Sanford L. Braver
Arizona State University Kuehnle, K. & Drozd, L. (Eds.) Parenting Plan Evaluations:
Applied Research for the Family Court. Oxford University Press.
Based on William V. Fabricius Opening Plenary: “30 Years of Research on Child Custody and Policy Implications”.  Presented at the Arizona Association of Family and Conciliation Courts Conference Sedona, AZ February 6, 2010.

(3) Bauserman:
Child Adjustment in Joint-Custody Versus Sole-Custody Arrangements: A Meta-Analytic Review Robert Bauserman  Journal of Family Psychology Copyright 2002 by the American Psychological Association, Inc. 2002, Vol. 16, No. 1, 91–102 0893-3200/02/$5.00 DOI: 10.1037//0893-3200.16.1.91 

(5) Warshak:

Psychology, Public Policy, and Law © 2014 American Psychological Association
2014, Vol. 20, No. 1, 46–67 1076-8971/14/$12.00 DOI: 10.1037/law0000005
Social Science and Parenting Plans for Young Children: A Consensus Report
Richard A. Warshak, University of Texas Southwestern Medical Center, with the endorsement of 110 researchers and practitioners listed in the Appendix