This document provides an overview of several major theories of social development. It begins by discussing why child development theories are studied and what theories aim to do. It then examines five key issues in developmental theory, including nature vs nurture. The document proceeds to summarize Freud's psychoanalytic theory, including his stages of psychosexual development. It also covers Erikson's psychosocial stages. Learning theories like classical and operant conditioning are explained, as are social learning theory. The document concludes by introducing ecological theories including Bronfenbrenner's bioecological model of interacting environmental systems influencing development.