There have been many approaches to explaining motivation. The instinct approach holds that motivations are caused by instincts, but most do not support this approach, since it is oversimplistic. The drive reduction approach holds that basic needs create drives, and motivation is the desire to reduce these drives.
Primary drives satisfy biological needs, while secondary drives satisfy non-crucial needs.
The arousal approach holds that people strive to maintain a constant level of stimulation and activity. The incentive approach holds that motivation is a result of the desire to please our senses. Cognitive approaches hold that motivation is a result of thoughts, expectations, and understanding of the world. One cognitive approach distinguishes between intrinsic motivation, the desire for self amusement and pleasure, and extrinsic motivation, the desire to obtain tangible reward. Abraham Maslow proposed a theory of motivation, in which he suggested a hierarchy of needs and that people are motivated to fulfill their most basic needs, before they pursue fulfillment of secondary needs.