Three influential theorists in human development were discussed along with their theories: Erik Erikson's psychosocial theory of development, Jean Piaget's theory of cognitive development, and Lev Vygotsky's sociocultural theory of development. The life span perspective recognizes that development occurs throughout one's entire life and is influenced both by heredity and environmental factors. Human growth is shaped by genetic predispositions interacting with physical and social environments from conception to death.