Definition from Nolo’s Plain-English Law Dictionary
The test that courts use when making decisions that affect a child. For example, an adoption is allowed when a court declares it to be in the best interests of the child. And in disputes over child custody, the judge will make a decision based on the child's best interests. Factors considered by the court in deciding the best interests of a child include: the child's age, sex, and mental and physical health; age, lifestyle, and mental and physical health of the parents; emotional ties between the parents and the child; ability of the parents to provide the child with food, shelter, clothing, and medical care; potential negative affect of changing the status quo; and the child's preference.