All states use a "best interest of the child" standard in disputed custody cases. But what does that actually mean in practice? Ultimately, it comes down to what a judge believes, based on the particular circumstances in a case.
Still, many state laws spell out a list of factors that judges must consider when deciding what's in the children's best interests. These factors vary from state to state. They can also vary from case to case—even states with a long list of specific factors invariably add something like "and any other relevant factor."
Here are some examples of the most common factors that judges typically must take into account.
The most basic part of the "best interests" standard is that custody decisions should serve the children's health, safety, and welfare. Judges will look at whether one or both parents are able to handle a child's special educational, medical, mental health, and other needs.
Many states have an explicit policy of encouraging frequent and continuing contact between children and their divorced or separated parents. In pursuit of that goal, judges will consider several factors related to the past and present parent-child relationships.
Judges will look at the parents' history of cooperating—or not— with each other around their parenting schedule. For instance, judges might want to know things like whether one parent interferes with visitation in any way.
Judges will also look for evidence of each parents' willingness to foster a good relationship between their child and the other parent. Is one parent bad-mouthing the other in front of the kids? Does one parent tend to start arguments when picking up or dropping off the child with the other parent?
The more cooperative parents will usually have an edge in a custody dispute. And parents who are obviously trying to alienate a child from the other parent—or who just can't refrain from undermining the other parent's relationship with the kids—will learn the hard way that judges don't look kindly on that type of behavior.
Judges will look at each parent's history of taking care of and spending time with their children on a day-to-day basis. Sometimes, parents who haven't been much involved with their kids' lives suddenly develop a strong desire to spend more time with the children once the marriage has ended.
In many cases, this desire is sincere, and a judge will respect it—especially if the parent has been dedicated to parenting during the separation period. But the judge will definitely take some time to evaluate the situation to make sure that a parent isn't requesting custody primarily to win out over the other parent, and that a parent with little experience of daily caretaking can follow through with those new-found wishes.
Obviously, when there's clear evidence of child abuse or neglect, a judge will limit the abusive parent's contact with the children. If judges do award visitation in these cases, it will usually be supervised and structured in a way to protect the children from future emotional or physical harm.
Domestic violence against the other parent will also play into custody decisions, particularly when the kids have witnessed the abuse..
When it comes to children, judges are big on the status quo, because most of them believe that piling more change on top of the traumatic transition of divorce generally isn't good for kids. Among other things, judges may look at the child's ties to the current school and community.
So if you're arguing that things are working fine, you've got a leg up on a spouse who's arguing for a major change in the custody or visitation schedule that's already in place.
Several other factors that judges consider are related to children's need for stability after divorce.
There's a bit of a chicken-and-egg dilemma surrounding the issue of which parent keeps the family home and how that affects custody. Often, the judge awards the home to the parent with physical custody of the children, because that will provide stability and continuity in the children's lives. Other times, the judge awards custody to the parent who's going to stay in the family home, for the same reason.
Whether you're the "out-parent" (the one who isn't staying in the family home), or neither you nor your ex were able to keep the house after divorce, you'll need to prove that your current living situation would be a good place for the children to spend a lot of time if you want primary or shared custody. Don't expect to get that result if you're crashing in your best friend's guest room while you get back on your feet after the divorce.
At the same time, most judges will try to avoid penalizing parents who can't afford a nice home with an ideal set-up for kids. (It's also worth noting that the child support laws in many states allow judges to consider the differences in living standards between the parents' households when they're deciding on the amount of child support in cases where the kids will spend time with both parents.)
The proximity of your home to your spouse's may also factor in to the judge's custody decision. The closer you are to each other, the more likely it is that the judge will order a time-sharing plan that gives both parents significant time with the kids. When parents live in the same community, their children can continue with their same social, sports, and religious activities regardless of which parent they're staying with on which day. Geographical distance becomes more important as kids get older and maintain stronger bonds with their friends.
It's also less taxing on the children to go back and forth between parents who don't live far apart.
Depending on the state and the children's maturity, judges may talk to kids to find out where they want to live and how much time they want to spend with each parent. Or judges may learn about the children's opinions from a custody evaluator.
Some states require judges to consider children's custody preferences when they've reached a certain age, but they may listen to younger children's view when it's appropriate. In other states, the requirement isn't about the child's age as much as the ability to express an opinion based on sound reasoning—not on things like which parent will let them stay up late.
Still other states disapprove of bringing the children into custody decisions at all.
The "tender years" doctrine—the idea that young children should stay with their mothers—has long been officially out of fashion. The gender of the parents is not a factor to be considered in custody decisions, but some states still allow judges to consider the children's age. And some judges continue to believe that younger children should live with their mothers, especially when the mother has been the primary caregiver. Certainly, it's not likely that a father would be awarded sole custody of a nursing baby.