Fathers of young children were historically at a disadvantage in seeking custody of their children due to tender years doctrine—a theory courts adopted in the belief that children had a greater need for the love and care of their mothers during their tender years. Under the tender years doctrine, custody of young children was automatically given to the mother unless there were unusual circumstances. Today, courts more often recognize the important role both parents play in the lives of young children, and usually order some form of shared custody arrangement. But there are factors the court may consider that sometimes favor one parent over the other in determining who will be the primary custodian of the children—such as giving preference to a parent who has not been working outside the home, and has therefore been spending more time taking care of the children’s daily needs.

In Massachusetts, the tender years doctrine, which historically favored mothers in child custody cases, is no longer a legal standard. Instead, Massachusetts courts focus on the best interests of the child when making custody determinations. This approach considers various factors without an automatic preference for one parent based on gender. Factors that may influence custody decisions include the child's relationship with each parent, the parents' ability to provide for the child's needs, and the child's adjustment to home, school, and community. While the court may consider which parent has been the primary caregiver, particularly if one parent has not been working outside the home, this is just one of many factors evaluated. The goal is to ensure a stable and nurturing environment for the child, and courts are increasingly favoring shared custody arrangements that allow both parents to play an active role in their children's lives, unless evidence suggests that such an arrangement would not be in the child's best interests.