The debate over whether children of divorce should generally be subject to split child custody rages on. The latest state to consider changing its custody laws to presume shared custody is north of the border in Missouri.

As in Arkansas, Missouri law requires that the child’s best interests are the top priority when working out a child custody arrangement. A bill before a state legislative committee there would amend the law to explicitly state that spending half their time with each parent is in a child’s best interests. While family court judges would not be required to issue 50-50 custody splits, inserting this language would “encourage judges to pay more attention to research” that supports such arrangements, KCUR-FM reports.

That research suggests that children do better when they have equal access to both parents, according to the president of National Parents Organization. He said the best arrangements have the parents trade off weeks. He also believes that making shared custody the default plan would reduce the number of ugly custody battles.

In Arkansas, it is common for both parents to share joint legal custody of their children. This gives both parents a say in important child-rearing decisions. However, this is separate from physical child custody, which determines where the children will live. Often, one parent will have primary physical custody, meaning he or she will care for the kids most of the time. The other parent will receive visitation rights to spend time with the children.

Which system works best will continue to be hotly debated across the country for some time.