This summer I've developed a scholarly interest in an area of family law known as "shared parenting presumptions." The issue is this: if parents* divorce and have children, what is the most fair and just custody arrangement for the children?
Advocates of shared parenting presumptions argue that we should presume from the outset that the child(ren) will share their time with each parent roughly equally: this is an initial position of fairness and justice, and respects parents' rights to their children and children's rights to their parents.
Of course, there might be, and often are, good reasons why equality this would not be the most fair and just (or desired, by all parties) arrangement, but a presumption can accommodate that: we can, and should, deviate from equality when there are good reasons to do so, when strong evidence has been presented that equality is not most fair and just, given the facts of the case.
In most states, there is at least an informal presumption against equality, and there are barriers to seeking it. The working presumption often is that the child(ren) will spend most of their time with one parent and so spend "every other weekend and one night a week" with the non-custodial parent. A parent who seeks equality typically has argue for equality, often at considerable costs, financial and emotional.
The issue can be seen in terms of a "burden of proof": should the burden of proof be on those who seek equality, or the burden of proof be on those who oppose equality? Since equality is, from a starting point, fair and just, we should start there, so argue advocates of shared parenting.
There are many issues here: legal issues, social science about child development, and concerns about gender stereotypes. And they are couched in basic moral or ethical about justice and fairness, and the goods of parent-child relationships, and mediating conflict.
If anyone, especially in Georgia (since these issues are state-specific) is interested in these issues, I'd appreciate hearing from you since there is a lot to learn here. I anticipate writing something on these issues soon enough. For more on the legal issues, see this post "Joint Legal Custody is Your Constitutional Right."
* My discussion above concerns a male-female married couple. These issues are likely more complicated if the couple is not married, the couple is of the same sex, the child is adopted, paternity is not established or is in dispute and so on.