A 6 page paper. are many developmental psychologists and theorists. This essay discusses four developmental theorists: Piaget, Kohlberg, Erikson, and Freud. Each focused on different aspects of development, cognitive, moral, psychosocial, and psychosexual, respectively. Chronologically, Freud came first in the mid-1930s but each was a forerunner in his work. This essay briefly discusses the ...