The object of any custody order is to ensure the health and well-being of the children involved, and to make sure they have access to both parents. However, parents can have difficulty achieving this when they have an adversarial relationship. Decisions and time with the children can become a power struggle and a tug-of-war. Parents may find themselves focusing on “winning” and besting their ex, forgetting the best interests of their children in the process. In particularly acrimonious relationships, it's usually better for the children when one parent has full custody.
A parent who has full or sole legal custody has control of all major decisions affecting the child’s life. When parents have joint legal custody, they both have this authority. When parents who don’t get along attempt joint legal custody, they might find themselves constantly arguing over important decisions. If they can’t agree, neither of them can act. For example, if a child needs orthodontia and one parent with joint legal custody does not agree that the expense is necessary, the child cannot have her teeth aligned without the approval of the court. The parent in favor of the braces would have to petition the court for permission. This can result in a lot of additional legal fees and court costs after the divorce is final. When one parent has full legal custody, such stalemates are avoided. However, the parent without legal custody rights might feel as though he's lost all control over his child's life.
It’s difficult logistically to divide a child’s time exactly 50/50 between households, so even when parents share joint physical custody, their child might live with one more often than the other. Legally, joint physical custody means your child lives with each of you roughly an equal amount of time. However, in practice, it usually translates to your child using one parent’s home as “home base” and spending a considerable amount of visitation time with the other parent, as much as three or four overnights a week. This means parents will be exchanging their children and coming into contact with some frequency. When these occasions always result in bickering, the child may feel as though she’s in the middle of it, or even the cause of the strife. Full physical custody to one parent, with typical visitation to the other parent every other weekend or so, minimizes the contact between them and its stress on their child. However, the noncustodial parent in such an arrangement would not have much time with his child.
When parents put aside their own differences long enough to reach an agreement regarding custody terms, courts will almost always honor those agreements and sign them into orders. Most states encourage or even mandate custody mediation for this reason. Courts also prefer to award joint legal custody so both parents have an active role in their child’s life. Judges and mediators sometimes compromise regarding legal custody when parents don't get along, putting one parent in charge of educational decisions, and the other in charge of medical decisions. This avoids repeated trips back to court every time a major decision is required and the parents can't agree. Each parent would have full legal custody in a particular area of their child's life. Neither would feel that he had no say in his child's upbringing, as would be the case when only one parent has full legal custody.
Compromises With Living Arrangements
In extremely contentious relationships where the parents want to share physical custody, exchanging the children on alternating weeks can cut down on their contact and opportunities for bickering. For example, the child might live one week with mom, the next week with dad, then return to mom’s home again. Parents would only have to physically interact 52 times a year. The advantage over full physical custody to one parent is that this arrangement ensures that both have “real” parenting time on a regular basis. They're dealing with homework and day-to-day mundane issues, not just visitation, which usually means fun and relaxing time.