premise: Among infiuential explanations of why preschoolers are so drawn to pretending , Freud 's psychoanalytic theory and Piaget 's cognitive theory held sway for much of the twentieth century and true is true and true is true and true is true and true is true and true is true .
hypothesis: Freud 's psychoanalytic theory and Piaget 's cognitive theory explains why preschoolers like to pretend .