a process by which a consequence immediately follows a behavior which decreases the future frequency of that behavior. As with reinforcement, a stimulus can be added (positive punishment) or removed (negative punishment). Broadly, there are three types of punishment: presentation of aversive stimuli (e.g. pain), response cost (removal of desirable stimuli as in monetary fines), and restriction of freedom (as in a 'time out'). Punishment in practice can often result in unwanted side effects. Some other potential unwanted effects include resentment over being punished, attempts to escape the punishment, expression of pain and negative emotions associated with it, and recognition by the punished individual between the punishment and the person delivering it. "He would use loud sounds of 100 decibels on two 5-year-old autistic twins" Extinction Extinction is the technical term to describe the procedure of withholding/discontinuing reinforcement of a previously reinforced behavior, resulting in the decrease of that behavior. The behavior is then set to be extinguished (Cooper et al.). Extinction procedures are often preferred over punishment procedures, as many punishment procedures are deemed unethical and in many states prohibited. Nonetheless, extinction procedures must be implemented with utmost care by professionals, as they are generally associated with extinction bursts. An extinction burst is the temporary increase in the frequency, intensity, and/or duration of the behavior targeted for extinction. Other characteristics of an extinction burst include an extinction-produced aggression—the occurrence of an emotional response to an extinction procedure often manifested as aggression; and b) extinction-induced response variability—the occurrence of novel behaviors that did not typically occur prior to the extinction procedure. These novel behaviors are a core component of shaping procedures. Discriminated operant and three-term contingency In addition to a relation being made between behavior and its consequences, operant conditioning also establishes relations between antecedent conditions and behaviors. This differs from the S–R formulations (If-A-then-B), and replaces it with an AB-because-of-C formulation. In other words, the relation between a behavior (B) and its context (A) is because of consequences (C), more specifically, this relationship between AB because of C indicates that the relationship is established by prior consequences that have occurred in similar contexts. This antecedent–behavior–consequence contingency is termed the three-term contingency. A behavior which occurs more frequently in the presence of an antecedent condition than in its absence is called a discriminated operant. The antecedent stimulus is called a discriminative stimulus (SD). The fact that the discriminated operant occurs