Negative reinforcement occurs when we remove an aversive stimulus. An aversive stimulus is anything that, other things being equal, organisms move away from. While all change is characteristic of stimuli, excessive change is aversive. The intensity or magnitude of energy change determines whether it is simply a stimulus, a reinforcer, or aversive. I may be comfortable driving my automobile at ninety miles per hour, but I do not enjoy being a passenger in a car driven that fast by someone else.
People pay to ride roller coasters, yet find similar movements frightening in an airplane.
Whether we can do anything to control a situation has something to do with whether it is aversive. If I know that I can terminate an otherwise aversive situation myself, I may even enjoy it. Successfully walking away from a roller coaster ride reinforces me for having bought the ticket, but if I am trapped in the car, I am unlikely to repeat the experience. Adaptation to environmental change is the concern, not only of learning theory, but of psychology in general. Every new skill, every new fact that we learn, entails some adjustment to change.