This document discusses several psychological concepts related to motivation theory. It describes intrinsic motivation as internally driven, such as doing something for pleasure or importance, versus extrinsic motivation which comes from external factors. Two main motivation theories are also summarized: instinct theory which proposes we are born with innate tendencies to survive, and drive reduction theory where we are motivated to reduce internal drives like hunger. Intrinsic motivation is discussed as stronger than extrinsic motivation, though external rewards can decrease internal motivation by changing the reason for an activity from enjoyment to obtaining a reward.