Are yams and sweet potatoes the same?
pleasure principle pleas·ure principle (plězh'ər)
In psychoanalysis, the tendency or drive to achieve pleasure and avoid pain as the chief motivating force in behavior. Also called pain-pleasure principle.
In psychoanalysis, the demand that an instinctive need (usually sexual or aggressive) be gratified, regardless of the social or practical consequences. Sigmund Freud held that the id was dominated totally by the pleasure principle, but that, with the development of the ego and superego, individuals become aware of the demands of social reality (the reality principle), and thereby learn to temper and regulate their quest for pleasure.