A child cannot decide whether they will live with one parent or the other when younger than 18. The judge ultimately makes the decision. The judge may consider the child's opinion in some cases. Whether the preference of the child is considered depends on the child's maturity, age, and ability to adequately express a reasonable preference. However, if it is clearly in the best interest of the child to be in the custody of one parent, the judge's decision will not be swayed.