1. Theories of Motivation

2. Instincts
Motivation explained in terms of survival instincts like hunting, fear, rivalry, etc.

3. Drive-Reduction Theory
Motivation occurs because of an attempt to bring balance back to the body (homeostasis)

4. Arousal Theory
Motivation occurs in an attempt to achieve an optimal level of arousal:
At times we are motivated to increase the state of arousal, other times we are motivated to decrease it.

5. Harvard psychologist David McClelland added three possible motivators based on psychological needs:
Need for achievement
Need for affiliation
Need for power