 Emerging adulthood is a new demographic, is contentiously changing, and some believe that twenty-somethings have always struggled with "identity exploration, instability, self-focus, and feeling in-between".Arnett called this period "roleless role" because emerging adults do a wide variety of activities, but are not constrained by any sort of "role requirements".The developmental theory is highly controversial within the developmental field, and developmental psychologists argue over the legitimacy of Arnett's theories and methods.