Roger is a playful 1-year-old. During his playtime, his father sometimes hides one of his toys to see if Roger realizes that the toy is missing. Roger begins a prompt search for the toy as soon as he notices that it is missing. According to Jean Piaget's theory of cognitive development, Roger appears to be in the
Roger appears to have entered the preoperational stage according to Jean Piaget's theory of cognitive development, because Roger's broad problem solving skills have begun to develop.
