Positive Reinforcement and Negative

Reinforcement schedules are derived from the timing and patterning of reinforcement response. Reinforcement may be scheduled in numerous ways, based upon the number, or sequencing, of responses, or on certain timing intervals with respect to the response. The consequences of behaviors always operate on some sort of schedule, and the schedule can affect the behavior as much as the reinforcement itself. For this reason a significant amount of research has focused on the effects of various schedules on the development and maintenance of targeted behaviors.

In operant conditioning research, two particular types of schedules that have been studied extensively are ratio and interval schedules. In ratio schedules, reinforcers are presented based on the number of responses made. In fixed-ratio schedules, a reinforcer is presented for every fixed number of responses so that, for example, every fifth response might be reinforced. In variable ratio schedules, responses are reinforced using an average ratio of responses, but the number of responses needed for reinforcement changes unpredictably from one reinforcement to the next. Using the interval schedule, reinforcements are presented based on the length of time between reinforcements. Thus, the first response to occur after a given time interval from the last reinforcement will be reinforced. In fixed interval schedules, the time interval remains the same between reinforcement presentation. In variable interval schedules, time intervals between reinforcements change randomly around an average time interval.

Research has shown that small differences in scheduling can create dramatic differences in behaviors. Ratio schedules usually lead to higher rates of response than interval schedules. Variable schedules, especially variable interval schedules, lead to highly stable behavior patterns. Furthermore, variably reinforced behaviors resist extinction, persisting long after they are no longer reinforced. This is why it is often difficult to extinguish some of our daily behaviors, since most are maintained under irregular or variable reinforcement schedules. Gambling is a clear example of this phenomenon, as only some bets are won yet gamblers continue taking their chances.