This document discusses various theories of motivation: - Instinct approaches view motivation as biologically determined innate patterns of behavior. William McDougall proposed 18 instincts including curiosity and aggression. - Drive-reduction approaches see motivation in terms of needs and drives that create psychological tension and physical arousal until fulfilled. - McClelland identified the needs for achievement, affiliation, and power as important motivators. - Arousal approaches like the Yerkes-Dodson law examine how different levels of arousal impact performance. - Incentive approaches see behavior as motivated by external rewards. Expectancy-value theories consider beliefs, values, and expectations. - Humanistic approaches focus on cognitive, aesthetic, and transcendence