Wanting psychology to be a more precise science, researchers in the field of psychology turned to physics and created "behaviorism", which is based upon Newton's one-way cause effect mechanics.

Behaviorism attempts to explain behavior without referring to unobservable internal forces such as thoughts or needs. It explains behavior by focusing only upon the behavior that can be observed: the behavior itself and the environmental events that proceed and follow it, which thus becomes its main weakness in a learning environment -- behaviorism is about the observable, yet learning takes place within the unobserable -- the mind.

I have always found behaviorism a quite interesting concept, although mostly wrong. Thus, when I came across this documentary on rats, I wondered how yesterdays' behaviorists would describe today's generation as they "pushed" the keys on their computers, cell phones, and iPods. How would they describe their drive? What is their reward?

Note: the page that the movie is located on is Motivation and Reward in Learning (1948)