The superego consists of two parts, the conscience and the ego-ideal. The conscience is the familiar metaphor of angel and devil on each shoulder. The conscience decides what course of action one should take. The ego-ideal is an idealized view of one's self. Comparisons are made between the ego-ideal and one's actual behavior. Both parts of the super-ego develop through experience with others or via social interactions. According to Freud, a strong super-ego serves to inhibit the biological instincts of the id, while a weak super-ego gives in to the id's urgings. Further, the levels of guilt in the two cases above will be high and low, respectively.