This chapter discusses theories of social and personality development in infancy. It covers psychoanalytic perspectives from Freud and Erikson, attachment theories from Bowlby and Ainsworth, and the development of temperament and self-concept. Key points include Freud's oral stage and Erikson's trust vs mistrust stage. Bowlby identified 4 phases of attachment and Ainsworth described secure and insecure attachments. Temperament is influenced by both heredity and environment. The effects of nonparental care depend on the quality of care and can impact cognitive and social development, especially if started before age 1.