In his pioneering work on child behavior, the American developmental psychologist Arnold Gesell claimed that infants as young as four weeks display signs of handedness and that right-handedness is clearly established by age one.
By observing and filming infants and young children, and analyzing their functioning by studying the films frame by frame, Gesell delineated 10 normal stages of early childhood development.
Gesell, who founded the Clinic of Child Development at Yale University in 1911.
Gesell., 1903, pp. 113-158), K.