Joint custody and shared parenting have been studied for more than a quarter-century, with the majority of studies indicating significant benefits for children.  About a third of existing studies show no difference between joint and sole custody for children's adjustment to divorce.  The critical factor appears to be conflict between parents.  When parents cooperate and minimize conflict, children do much better with shared parenting.  If there is significant conflict between parents, however,  children may do no better (but no worse) than they do in sole custody.  This section summarizes some of the research published in the past two decades.

Contents
Joint Physical Custody -the arrangement in which a child spends at least one-third of their time with each parent, often 50/50 time division between parents.
Joint Legal Custody -  situations in which both parents have  some legal decision-making role, but the child's living arrangement is the same as sole custody (non-custodial parent is permitted four days a month with the child).
Extreme Situations - cases of high conflict, sometimes including domestic violence.
Sole Custody - the traditional arrangement in which the child lives with one parent and visits the other parent every other weekend, plus two weeks in summer.

See also
Kelly, J., Current research on children's postdivorce adjustment. Family and Conciliation Courts Review, 31.29-49, 1993
Full report  text in PDF format

On child satisfaction:  "Children have expressed higher levels of satisfaction with joint physical custody than with sole custody arrangements; citing the benefit of remaining close to both parents. Joint custody does not create confusion for the majority of youngsters about their living arrangements or about the finality of the divorce, nor does increase loyalty conflicts (Leupnitz, 1982; Shiller, 1986a, 1986b; Steinman, 1981)."

On parent satisfaction:  "A surprising finding in one study was that mothers who share custody are more satisfied than those having sole custody and whose children see their father periodically. However, both groups expressed more satisfaction with their residential arrangement than did sole-custody mothers whose children had no paternal contact."

On conflict situations:  "Dual-residence (joint physical custody) parents had the highest co-operative-communication scores but did not differ from mother custody or father custody parents in the amount of discord. Shared residence did not exacerbate or diminish conflict but did appear to lead to more co-operative communication."

On child adjustment:  "The adjustment of 517 adolescents (aged 10 years, 6 months to 18 years) in three residential arrangements was compared 4.5 years after separation by Buchanan, Maccoby, and Dornbusch (in press). Looking at both family process and status variables, these researchers assessed adolescent adjustment in terms of depression, deviance, school effort, and school grades. Statistically, more boys were in dual-residence and father-residence arrangements, whereas more girls were in mother-residence arrangements. Overall, dual-residence adolescents were better adjusted than were mother-residence adolescents."

Fabricius, W.V. and J. Hall, (2000)  "Young Adults Perspective on Divorce", Family and Conciliation Courts Review, Vol. 38, 446-461.

"Our participants, who have lived through their parents' divorces and have now entered young adulthood (and college) have given us their 'expert' advice.  Seventy percent of them, men and women alike, believe that living equal amounts of time with each parent is the best arrangement for children."

Full text in PDF

Amato, P. R. (2000). The consequences of divorce for adults and children. Journal of Marriage and the Family, 62(4), 1269-1287.

"Divorce also has significant impacts on children, according to the research. Many of these  impacts tend to be negative. Children are more likely to be poor after divorce, and more likely to experience instability. However, moderating factors include children’s coping skills, and the presence of joint custody. "  from abstract

Christoffersen, M. N. (1998). Growing up with dad: A comparison of children aged 3-5 years old living  with their mothers or their fathers. Childhood, 5(1), 41-54.

This Danish study used a scientific sample, drawn from national birth records, of 478 single fathers and 532 single mothers, including situations that can be classified as joint physical custody.  Results indicated that children fared better with single fathers, possibly as a result of greater contact with the other parent (i.e. joint physical custody with mother), economic stability of fathers, and more social support, including greater contact with grandparents.

"Psychologists Becoming More Sophisticated In Their Custody Evaluation Practices, Survey Finds"
                   More Inclined Toward Joint Custody; Less Likely to Make Judgments Based on a Single Factor than 10 Years Ago

This report shows that joint custody is becoming the option of choice among experts:
"While in 1986 more than half of the situations on the list prompted an endorsement of one parent over the other, by 1996, less than a quarter of the items resulted in endorsement of one parent over the other, indicating a greater preference for joint custody over sole- or single-parent custody than in 1986."
APA announcement:  http://mirror.apa.org/releases/custody.html

Adolescents After Divorce, Buchanan, C., Maccoby, and Dornbusch, Harvard University Press,1996.

A study of 517 families with children ranging in age from 10.5 years to 18 years, across a four and a half year period. Measures were: assessed depression, deviance, school effort, and school grades.   Children in shared parenting arrangements were found to have better adjustment on these measures than those in sole custody.

Joan B. Kelly, one of the most respected experts in the field of children and divorce, summarized the Buchanan, Maccoby and Dornbusch study as follows:   "The adjustment of 517 adolescents (aged 10 years, 6 months to 18 years) in three residential arrangements was compared 4.5 years after separation by Buchanan, Maccoby, and Dornbusch (in press). Looking at both family process and status variables, these researchers assessed adolescent adjustment in terms of depression, deviance, school effort, and school grades. Statistically, more boys were in dual-residence and father-residence arrangements, whereas more girls were in mother-residence arrangements. Overall, dual-residence adolescents were better adjusted than were mother-residence adolescents."  (Current research on children's postdivorce adjustment. Family and Conciliation Courts Review, 31.29-49, 1993)

This US Government report reviewed physical custody of children following divorce.  Although it did not study children's adjustment, it is significant because it demonstrates that shared parenting (joint physical custody) is becoming commonplace, especially where statutes or courts are supportive. In four of 19 states surveyed, joint physical custody exceeded 30%.

Findings regarding physical custody were summarized by the authors:  "In 1990 the wife was awarded custody of the children almost three-fourths (72 percent) of the time in those divorces in which custody was awarded. Joint custody was the second most common arrangement (16 percent) while husbands were awarded custody in 9 percent of these divorces."

Division 16, School Psychology, American Psychological Association, Report to the U.S. Commission on Child and Family Welfare, June 14, 1995.

This report "summarizes and evaluates the major research concerning joint custody and its impact on children's welfare." The report concludes that "The research reviewed supports the conclusion that joint custody is associated with certain favorable outcomes for children including father involvement, best interest of the child for adjustment outcomes, child support, reduced relitigation costs, and sometimes reduced parental conflict." The APA also noted that "The need for improved policy to reduce the present adversarial approach that has resulted in primarily sole maternal custody, limited father involvement and maladjustment of both children and parents is critical. Increased mediation, joint custody, and parent education are supported for this policy."

Full report text in PDF format

"Joint custody is also the preferred option in high conflict situations because it helps reduce the conflict over time - and that is in the best interests of the children."

Bender reviews current and historical research on the 'myths' of joint custody, i.e. - that joint custody should not be awarded when the mother objects or in high conflict matters.   The article describes the benefits of joint custody including that children adjust better post-divorce in joint custody as compared to sole custody awards, children's attachment to both parents post-divorce is essential for healthy child development, joint custody leads to higher levels of financial compliance, relitigation is lower as compared to sole custody, and joint custody leads to the best outcome for children even in high conflict situations because it forces resolution and best leads to reduction of child stress in the long term.

This study included "forty boys and girls, ages 8 to 12, in attendance at selected private secular and parochial schools in a large Southwestern metropolitan area participated, along with their middle to upper-class parents." The study compared adjustment of children in joint and sole physical custody, controlling for level of conflict between parents, to determine if parental conflict would be more detrimental to children in joint or sole custody.  The author summarized findings as follows: "Overall, no significant difference between joint and sole physical custody groups was found." 

Rockwell-Evans, Kim Evonne, "Parental and Children's Experiences and Adjustment in Maternal Versus Joint Custody Families " Doctoral dissertation, 1991. North Texas State U.

This study compared 21 joint custody and 21 maternal custody families, with children between the ages of 4-15.

Results showed that misbehavior and "acting out" were more common among sole custody children: "A multiple regression analysis of these data found children in joint custody families had fewer behavioral adjustment problems with externalizing behavior than children in mother custody families." "Regardless of custody arrangement, parents with low self esteem were more likely to have children with behavioral adjustment problems when predicting the child's overall behavioral adjustment and internalized behavior." 

J. Pearson and N. Thoennes,"Custody After Divorce: Demographic and Attitudinal Patterns", American Journal of Orthopsychiatry, Vol. 60, 1990.

"Consistent with other studies of joint and sole custody [citations], our joint legal and residential noncustodians were decidedly more involved with their children following divorce than were noncustodians in sole custody arrangements. . . . Lastly, respondants in joint custody arrangements wre more apt to perceive their exsopuse as having a good relationship with the children and to report satisfaction with that person's performance as a parent."

" . . . conflict between divorcing parents in our sample did not appear to worsen as a result of the increased demand for interparental cooperation and communication in joint legal or joint residential custody arrangements. To the contrary, parents with sole maternal custody reported the greatest deterioration in the relationships over time." 

Glover, R. and C. Steele, "Comparing the Effects on the Child of Post-divorce Parenting Arrangements," Journal of Divorce, Vol. 12, No. 2-3 (1989).

This study evaluated children aged 6 to 15 in the areas of locus of control, self-concept, and family relationships.  The children were divided into three groups:  shared custody, maternal custody, and intact families.  Intact family children had averaged higher than divorced family children on self-concept and father relationships, and shared custody children averaged higher the sole custody children in these areas.  Intact family children had fewer least-positive responses in all areas than divorced family children, and shared custody children had fewer least-positive responses than sole custody children in all areas except mother relationship.  This study indicates that, on average, a two parent intact family is the best arrangement for children, and a shared parenting arrangement is better than a sole custody arrangement, i.e., a two-parent family is better even if parents are divorced. 

Ilfeld, Holly Zingale "Children's perceptions of their relationship with their fathers in three family constellations: mother sole custody, joint custody and intact families" Doctoral dissertation, U. of California, Davis 1989

This study evaluated children's perceptions of their fathers at least four years post-divorce, comparing joint custody, sole custody and intact families. The subjects were 43 latency-age children: 11 from maternal custody families, 14 from joint custody families and 18 controls from intact homes.

Results: "There was a significant difference in the perceptions of children in sole and joint custody. Joint custody children reported spending more time with their fathers in childcentered activities, activities which were considered pleasurable and important to children. " And: "No differences were found as a function of custody arrangements in children's perceptions of emotional closeness to the father, acceptance by the father, or fathers's potency or activity. " 

Lerman, Isabel A. "Adjustment of latency age children in joint and single custody arrangements" California School of Professional Psychology, San Diego, 1989

This study evaluated 90 children, aged 7 to 12, divided equally among maternal, joint legal, and joint physical custody groups.

Results showed negative effects for sole custody: "Single custody subjects evidenced greater self-hate and perceived more rejection from their fathers than joint physical custody subjects." Conflict between parents was found to be a significant factor, which may explain the better adjustment for joint physical custody children: "Degree of interparental conflict was a significant predictor of child self-hate. Higher conflict was associated with greater self-hate; lower conflict was associated with lower self-hate." "Higher father-child contact was associated with better adjustment, lower self-hate, and lower perceived rejection from father; lower father-child contact was associated with poorer adjustment, higher self-hate, and higher perceived rejection from father. "

Although not as beneficial to children as equal shared parenting (joint physical custody), joint legal custody helps to some extent. The main benefits of joint legal custody are in reducing visitation interference and improving child support compliance.

Joint legal custody has been consistently linked with more parental involvement, higher child support compliance, and less conflict between parents.  Until recently, however, it was not clear whether these benefits occurred as a result of joint legal custody, or simply because more cooperative parents chose joint custody in the first place.  The 1997 study by Seltzer provides strong evidence for a cause and effect relationship between joint legal custody and the benefits associated with it.

Gunnoe, M. L., & Braver, S. L. (in press, 2002). The effects of joint legal custody on family functioning, controlling for factors that predispose a joing award. Washington, DC: National Institute of Mental Health.

Gunnoe and Braver found that joint legal custody was associated with more father-child contact, and may reduce mothers' objections to visitation.  Custody type did not predict  parental conflict or parental adjustment to divorce.

Grall, T.. Child support for custodial mothers and fathers: 1997, Current Population Reports, Consumer Income Series P60-212  (2000). Washington, DC: Bureau of the Census, U.S. Department of Commerce.
Full report text in PDF format

This US Government research confirmed earlier findings that joint custody and visitation are significant in increasing child support compliance:
"Child support compliance was highly related to joint custody and visitation."
 

Amato, P. R. (2000). The consequences of divorce for adults and children. Journal of Marriage and the Family, 62(4), 1269-1287.

Another study which showed the negative effects of divorce on children and adults.  Moderating factors for adults were education and support of familiy and friends.  For children, moderating factors were children's coping skills and the presence of joint custody.

Scoon-Rogers, L. (1999). Child support for custodial mothers and fathers: 1995 (Current Population Reports, Consumer Income Series P60-196). Washington, DC: Bureau of the Census, U.S. Department of Commerce.
Full report text in PDF format

This US Government study found that visitation and joint custody increased child support payment rates.
 

Seltzer, J. A. (1998). Father by law: Effects of joint legal custody on nonresident fathers’ involvement with children. Demography, 35(2),135-146.  (journal publication of report described below).

Seltzer, J. "Father by Law: Effects of Joint Legal Custody on Non-residential Fathers Involvement with Children," NSFH Paper No. 75, Feb., 1997, U. of Wisconsin-Madison, http://ssc.wisc.edu/cde/nsfhwp/home.htm

Seltzer used data from the National Survey of Families and Households, a survey of over 13,000 families that collected data in two waves, 1987-88 and 1992-94. Because the study included data on the quality of family relationships, it was possible to study the effects of joint legal custody while controlling from pre-separation family relationships by analyzing data on families that had separated between the survey waves.

Seltzer concluded that "Controlling for the quality of family relationships before separation and socioeconomic status, fathers with joint legal custody see their children more frequently, have more overnight visits, and pay more child support than fathers in families in which mothers have sole legal custody." She suggests that joint legal custody helps reduce visitation denial: "By clarifying that divorced fathers are 'by law' still fathers, parents' negotiations about fathers' participation in child rearing after divorce may shift from trying to resolve whether fathers will be involved in child rearing to the matter of how fathers will be involved." [emphasis in original] 

Gunnoe, M.L., and S.L. Braver, "The Effects of Joint Legal Custody on Family Functioning, Controlling for Factors that Predispose a joint award," Child Development.

This study evaluated 273 families, controlling for 28 variables that influence a predisposition to agree on joint legal custody.  Controlling for these factors, children in joint legal custody families had more time with their fathers and fewer adjustment an behavior problems.  The custody type, however, did not affect the adjustment of fathers or mothers post-divorce, conflict between ex-spouses, or child support compliance. 

Sanford Braver,"Determining the Impact of Joint Custody on Divorcing Families",

Study consisted of 378 families; some with unmatched partners, in various custody arrangements.

". . .Sharlene Wolchik, Iwrin Sandler and I found in 1985 that children in joint custody had higher feelings of self-worth than children in sole maternal custody."

"Our results showed considerable benefits for joint custody, even when equating predisposing factors. After this adjustment, children in joint custody were found to be significantly better adjusted, and to exhibit less antisocial and implulsive behavior than sole custody families. Fathers also visited more, and were more involved in child care, as well as more satisfied with the divorce settlement. Mothers, however, were significantly less sataisfied with the custody arrangements in joint custody families."

"When the couple disagrees initially, which is better for the family, for the father to get his preference (joint [custody]) or for the mother to get her preference (sole [custody])? We found that the groups differed significantly in terms of how much financial child support was paid: when sole custody was that arrangement despite the fathers' wishes, 80% was paid (according to what the father reported; the figure was 64% by mothers' report), while when joint custody was awarded despite the mothers' preference, it zoomed to almost perfect comliance (97% by fathers' report; 94% by mothers' report) . . . A similar relationship was found for fathers' contact with the child. It was significantly highest for the group in which joint custody was awarded despite the mothers' preference." "Joint custody, even when awarded despite the contrary preference of the mother, leads to more involved fathers, and almost perfect of financial child support; controlling for predisposing factors, it leads to better adjusted children. . . We belive these findings call for policy makers, in the best interest of the children, to adopt a presumption that is rebuttable for joint legal custody, that is, a judicial preference that both parents retain their right and responsibilities toward their children post divorce." 

Kelly, J. B.. Children’s adjustment in conflicted marriage and divorce: A decade review of  research. Journal of the American Academy of Child and Adolescent Psychiatry, 39, 963-973 (2000).

This study re-confirmed the negative effects of divorce and high conflict between parents (in divorce or marriage), particularly in risk of drug use, lower academic achievement and behavior problems.  However, some factors reduced problems:  1) children whose fathers remain involved with their school activities have better outcomes, 2) divorce and custody mediation results in lower conflict between parents, 3) joint custody leads to better outcomes for children.

Surviving the Breakup, J. Wallerstein and  J. Kelly;
Second Chances, J. Wallerstein and S. Blakeslee; and other publications.

Judith Wallerstein and colleagues have produced many publications on a 20+ year study of 184 families that had been referred to her clinic for therapy. The parents were predominantly mentally ill, with approximately half the men and half the women "moderately disturbed or frequently incapacitated by disabling neuroses and addictions," including some who were "sometimes suicidal." An additional 20% of the women and 15% of the men were categorized as "severely disturbed." Approximately one third of the sample were considered to have "adequate psychological functioning" before divorce. Although there was a significant level of attrition, with families dropping out of the study when problems were resolved, some conclusions emerged from the remaining families. Children in joint custody situations did no better than those in sole custody, indicating that parents must be reasonably psychologically healthy for shared parenting to benefit children.

Johnston, Janet R., Marsha Kline, and Jeanne M. Tschann,
"Ongoing Postdivorce Conflict: Effects on Children of Joint Custody and Frequent Access," American Journal of Orthopsychiatry, Vol. 59, No. 4 (Oct. 1989).

Johnston et al. studied 100 low income families involved in ongoing custody disputes that included frequent verbal and physical aggression. Approximately one third of the children were in joint physical custody arrangements averaging 12 days per month with the less-seen parent, with the others in either mother or father sole physical custody averaging 4 days a month with the less-seen parent. The study found that "there was no clear evidence that children are better adjusted in either custody type", and that "mean scores for the Child Behavior Checklist lie within the normal range for all custody types." Also, "there was no evidence that the clinically disturbed children were more likely to be in joint than in sole custody." However, the study did find that more frequent contact between parents in either joint or sole custody arrangements was "associated with more emotional and behavioral problems in the children."

Johnston's study indicates that shared parenting may not reduce disputes between parents in extreme high-conflict situations, but also shows that sole custody does not protect children from the effects of conflict between parents. In high conflict situations, it is probably better to reduce interaction between parents. For example, parents can pick up children from school instead of from the other parent's house.

The study did find one significant benefit from shared parenting even in these cases: "Only one parent with joint custody ceased contact with her child, whereas 12 parents of sole custody children 'dropped out'." Thus joint custody does appear to protect children from the complete loss of a parent, even in high conflict situations. 

"More than a quarter of American children—nearly 17 million—do not live with their father. Girls without a father in their life are two and a half times as likely to get pregnant and 53 percent more likely to commit suicide. Boys without a father in their life are 63 percent more likely to run away and 37 percent more likely to abuse drugs. Both girls and boys are twice as likely to drop out of high school, twice as likely to end up in jail and nearly four times as likely to need help for emotional or behavioral problems."  

Updated 5 June 2005