Louise Bates Ames was an American psychologist specializing in child development.[1] Ames was known as a pioneer of child development studies, introducing the theory of child development stages to popular discourse. Ames authored numerous internationally renowned books on the stages of child development, hosted a television show on child development, and co-founded the Gesell Institute of Child Development in New Haven, CT. Ames' work found that children go through clear, discrete developmental phases based on age. She demonstrated that various age groups feature unique behavioral patterns, to be considered by parents and doctors in monitoring children's development. Perhaps the best-known legacy of her work was the coining of the term "Terrible Twos," to describe the rigid, conflict-laden behavioral patterns of two-year-olds.