The Best Interests of a Child test is the standard by which the courts decide questions regarding Child Custody. To a certain extent, it should be common sense. For example, if one parent hits a child and the other parent doesn’t, then it’s in the child’s best interest for the child to go with the non-abusive parent. That is an extreme example, but that (in very basic terms) exemplifies the test.
Take for example a case where one parent wants to move to another state. We call these “Move-Away cases”. Since California is such an expensive place to live after separation, Move-Away cases happen quite often. So, in any Move-Away case, the Court has to ask, is it in the child’s best interest to stay in their present home with the non-moving parent, or is it in the child’s best interest to move away with the other parent*?
The Court is forced to look at an extremely long list of factors that go into the calculation of such a decision to make orders one way or the other. Keep in mind, almost everything, anything, is relevant. Which parent wants to move, which parent was the “primary caretaker” of the children, the distance of the move, the relationship between the parents and the children, the relationship between the parents themselves, which parent is more likely to share custody with the other parent after the move, age of the children, school, doctors, income, expenses, etc, etc, etc. In the end, ultimately it comes down to what is in the best interest of the child.