Few now accept the tabula rasa view of human psychology. Within each infant is a life force, innate aspects, that guide motives and meaning making. Carl Jung called our innate guiding systems archetypes. Archetypes influence the unfolding of development. Jung believed that humans, as an evolved species, inherit specific dispositions. These predispositions serve to guide our behavior, thoughts and emotions.
Jung suggested that the way an archetype matures, functions and blends with other archetypes is affected by our personality (genetics) and our experience (environment). He stated that because our inner archetypes are designed to do different things and pursue different goals (old brain/new brain), they can be in conflict with each other.
For Jung, how our parts interact is the source of our internal conflict. In other words, the way archetypal processes mature, develop and integrate within the self that is the source of our problems.