Negative Reinforcement
Negative reinforcement is a term described by B. F. Skinner in his theory of Operant Conditioning. In negative reinforcement, a response or behavior is strengthened by stopping, removing, or avoiding a negative outcome or aversive stimulus.
Aversive stimuli tend to involve some type of discomfort, either physical or psychological. Behaviors are negatively reinforced when they allow you to escape from aversive stimuli that are already present or allow you to completely avoid the aversive stimuli before they happen.