The document presents summaries of several theories of child development: - Erik Erikson's psychosocial theory which describes eight stages from infancy to adulthood where individuals face new challenges. - Sigmund Freud's psychosexual theory which argues that development is determined by early childhood experiences and how anti-social impulses are handled. - Edward Thorndike's connectionism theory which views learning as forming associations between stimuli and responses through reinforcement. - Jean Piaget's cognitive developmental theory where children actively construct understanding through assimilation and accommodation of new information. - Lev Vygotsky's sociocultural theory which emphasizes how human development is influenced by cultural and historical contexts through use of artifacts.