the view postulating that humans are governed by the favor for instinctual pleasure, or satisfaction, and for the release of tension which cultivates as pain or unsatisfaction whenever pleasure is lacking. in accordance with psychoanalytic theory, it is the psychic force which drives individuals to seek out immediate pleasure of instinctual, or libidinal, urges, like sexual intercourse, hunger for food, thirst, and excrement. It overcomes the id and operates most greatly during childhood During adulthood, it is opposed by the ego’s reality principle. Commonly referred to as satisfaction-pain standard.