Motivation
"Motivation" is a theoretical construct that is used to explain behavior such as actions, needs and desires. Thirst is a motivation that is tied to the individual's desire to survive and is therefore a primary motivator, Social motivation (the desire to be around other people), on the other hand, is not essential for survival, and is considered a secondary motivator, Controlling these factors, as in an experiment, can serve as powerful means to control the behavior of others.
Why do you eat? Why do you drink? What makes you do anything? The answer is motivation; a process that acts, guides, and maintains behaviors. For example, when you have not eaten for a period of time, you will eventually start having the feeling of hunger, which motivates you to eat something, and thus reduce the feelings of hunger.