The parents are the time and motion study and efficiency experts Frank Bunker Gilbreth Sr. and psychologist Lillian Moller Gilbreth. The film shows typical days in the lives of a family in the 1920s, but here with 12 children and an efficiency engineer as the parent. Frank employs his unorthodox teaching methods on his children, and there are clashes between parents and children. Frank takes every opportunity to study motion and increase efficiency, including filming his children's tonsillectomies to see if there are ways to streamline the operation.