Washington Revised Code Title 26. Domestic Relations § 26.09.002. Policy

Parents have the responsibility to make decisions and perform other parental functions necessary for the care and growth of their minor children.  In any proceeding between parents under this chapter, the best interests of the child shall be the standard by which the court determines and allocates the parties' parental responsibilities.  The state recognizes the fundamental importance of the parent-child relationship to the welfare of the child, and that the relationship between the child and each parent should be fostered unless inconsistent with the child's best interests.  Residential time and financial support are equally important components of parenting arrangements.  The best interests of the child are served by a parenting arrangement that best maintains a child's emotional growth, health and stability, and physical care.  Further, the best interest of the child is ordinarily served when the existing pattern of interaction between a parent and child is altered only to the extent necessitated by the changed relationship of the parents or as required to protect the child from physical, mental, or emotional harm.