In the late 1800s, edward thorndike observed cats placed in a specially designed box. when a cat pressed a lever –, the cat could leave through a door that opened—a "– state of affairs" for the cat, as thorndike termed it. over time, the cats learned to press the lever –. learning a behavior by observing the consequences is called – conditioning. thorndike called the tendency of behavior with desirable results to be repeated the –.

Thorndike's term for the behavior you just described is something he called the "law of effect."  If an action produces a pleasant result, that effect will spur the behavior to be repeated.  If an action produces an unpleasant effect, that effect will condition the cat (or whomever) against repeating that action.  

The behavioral psychology of Edward Thorndike (1874-1979) had especially major impact on the field of educational psychology.  I'm going to hope that the law of effect as applied to your learning on means that you're pleased with this response and will come back to with other questions you have and topics you want to learn about!