A reinforcer is any consequence that causes the preceding behavior to increase . The increase may be in intensity, frequency, magnitude or some other quality. This is what most people think of as a reinforcer. Its proper name is positive reinforcer . There is another type of reinforcer.
Some behavior increases because it allows the subject to avoid something.
For example, cleaning the room allows a child to escape a parent's nagging. In this case, an event is subtracted or absent. When the behavior is emitted, the unpleasant or aversive stimulus stops. The behavior allows the person to escape an aversive situation and thus the behavior is repeated or increased the next time around. Positive Reinforcement the presentation of some event causes the behavior to increase.