Chapter 11 - what drives us: hunger, sex, friendship and achievement. Motivation: psychological & physiological factors that account for the arousal, direction, and persistence of behavior, need or desire that energizes and directs behavior. 1: genetically predisposed behaviors, drive-reduction theory, responses to inner pushes, arousal theory, right levels of stimulation, maslow"s hierarchy of needs, priority of some needs over others, instincts and evolutionary psychology. Instinct: complex behavior of unlearned, fixed patterns. Failed to explain most human motives: drive theories. Drive-reduction theory: physiological need (need for food or water) creates an aroused, motivated state (a drive) that motivates an organism to satisfy the needs. Homeostasis: physiological aim of drive reduction, tendency to maintain a balanced or constant internal state. Incentive: positive or negative environmental stimulus that motivates behavior, can lure or repel us. The sight of something attractive or threatening motivates us. Needs that are not met creates a drive. Drive pushed one to reduce the need.