Judges assign one parent as primary custody and the other as secondary parent. Physical custody essentially determines the time the child spends with each parent. Physical custody may be granted as sole physical custody (only one parent having the right to retain custody of a child), primary physical custody of a parent with access rights granted to the non-guardian parent or joint physical custody. Sole custody and shared custody agreements are relatively rare. In most cases, judges provide them with primary physical custody of a parent, while inserting access rights into the non-guardian parent. If the parents fail to reach an agreement, judges tend to award primary physical custody – normally to the mother, although they cannot take gender into account.