The Effects Of Aversive Control Onthe Discriminative Repertoire

The earlier discussion of the discriminative repertoire pointed out that seeing is a complex repertoire, more complicated than the simple effect of an incident stimulus on the receptor of the sense organ. Aversive stimuli also affect the control of behavior by stimuli. An example is a person's selective perception of his own characteristics, in the direction of not noticing undesirable features. Paying attention to, looking for, concentrating upon unpleasant aspects of one's environment is tantamount to punishment of the behavior by which one makes the observation. Hence, the general tendency in most organisms is to avoid noticing unpleasant situations. The process here is analogous to the one described in the discussion of repression. Observation of conditioned aversive stimuli arranges conditions for the reinforcement of any behavior which prevents these observations. The responses incompatible with observing the aversive stimuli are reinforced by terminating the aversive stimuli or the conditioned aversive stimuli generated by the incipient or partial behavior toward the aversive stimuli. Looking at, attending to, or listening to aspects of the environment which are conditioned aversive stimuli is equivalent to punishment of the performances involved in observing them. An extreme degree of loss of discriminative control occurs in a phenomenon denial, clinically defined as "mechanism of defense in which the facts or logical implications of external reality are refused recognition in favor of internally derived wish fulfilling fantasies" (J. C. Nemiah, 1961). Frequently, with the death of her husband, a widow may continue to behave as if the spouse were still alive. The wife, for example, watches for her husband's return through the window in the evening, or cooks enough food to include his portion or even sets a place for him in spite of the fact that she had attended his funeral several days before. In many cases, one of the major factors involved is that all of the behaviors which are customarily reinforced on the occasion of the live husband, such as setting a place at the table, now serve as avoidance responses, reinforced because they diminish the aversive effect of the loss of the spouse. The situation, of course, involves other factors and a complete analysis would also have to deal with other aspects in the positively reinforced repertoire of the patient which may also weaken discriminative control generally. Much "rationalization" may be dealt with by a similar analysis.

The same kind of loss of discriminative control is relevant to many other therapeutic problems, as, for example, the development of self-control in the case of the obese compulsive eater. To the extent that obesity is an aversive state of affairs, any verbal behaviors about the obese condition will be weak because they generate conditioned aversive stimuli. One of the major steps in a possible therapeutic procedure for obesity would be procedures for enabling the patient to develop strong verbal behavior about the ultimate aversive consequences, both physiologic and social, of being overweight. When the patient can verbalize the aversive consequences of being overweight, a retraining procedure can be started using the removal of the ultimate aversive consequences of being overweight as a reinforcement for the training procedures.

"Lying" may also develop as a result of escape or avoidance of aversive stimuli. A child who reports his activities accurately when he does something punishable, such as spilling ink on the carpet, may be punished for reporting the fact. Conversely, saying that someone else spilled the ink has the effect of avoiding the aversive consequences which the parent is likely to apply. The parent who punishes the child when he reports his activities accurately faces a dilemma in that the parent is punishing behavfor which he would probably like to encourage (telling the truth), while if he fails to punish he is allowing the child to emit responses which are ordinarily punished.

A Comparison Of Control By Negativeand Positive Reinforcement

Since so many of the clinical problems in behavior appear to arise as by-products of extreme aversive control, it would be well to compare the characteristics of behavioral control by positive and negative reinforcement and consider, for purposes of possible preventive mental health procedures, various alternatives in child rearing practices to some of those currently employed. Since one of the major effects of aversive control is to effect behavior in an individual by avoidance or escape, analogous to the maintenance of behavior by positive reinforcement, a comparison of the relative effects of positive and negative reinforcement in maintaining behavior is relevant here. In the practical control of behavior, both types of control may maintain a specific performance either singly or in combination.

An important factor in the tendency to use aversive control rather than positive reinforcement is the immediacy of the effect of an aversive stimulus. If the aversive stimulus is of large enough magnitude, the effect is to generate an avoidance or escape response which will be prepotent over any other behavior in the repertoire of the individual. This instant control over the behavior of the individual provides a very strong reinforcement for the controller and reinforces his disposition to continue the use of aversive control even though the effect is temporary. With the use of positive reinforcement, however, it may take a considerable amount of time for the contingencies to affect the performance significantly; particularly this is true in the case of extinction where an organism may emit a response literally thousands of times before its frequency of occurrence declines substantially.

Indirect Effects

At intensities and order of magnitudes where aversive stimuli become effective in controlling behavior via the processes of aversive control, aversive stimuli will, generally, disrupt or suppress a wide range of behaviors in a variety of situations. This disruption of the ongoing positively reinforced operant behavior of the individual may produce a serious weakening of the behavioral repertoire. The process may be autocatalytic. Positively reinforced behavior weakened by the aversive effects may in turn be less effective in producing its maintaining reinforcements; hence, the performance may become still weaker. This weakening could occur by a distortion of the form of the behavior and hence a reduction in its effectiveness in producing reinforcement, or via the effect of the schedule of reinforcement of the maintenance of the behavior. Consider, for example, the shy person telling a funny anecdote which doesn't quite come off properly because of the individual's shyness. The result will be that the subsequent tendency to tell funny anecdotes will be weakened because of the lack of effect on the audience.

Positive reinforcement, on the other hand, has minimal disruptive emotional effects. Positive reinforcement contingencies applied to specific responses will, in general, affect only the reinforced responses, and, perhaps, closely related ones; similarly with extinction. Extinction will affect large portions of an individual's repertoire only as larger and larger areas of a behavioral repertoire are no longer reinforced.

Likelihood Of Continued Control

Because the occurrence of an aversive stimulus provides the potential reinforcement of an escape or avoidance response, additional aversive control may be necessary in order to keep the individual exposed to the original aversive control. If the order of magnitude of the aversive stimulus is sufficiently strong to generate the required avoidance or escape response, then it is also of sufficient value to reinforce behavior which will remove the individual from control by the aversive controller. In the complex case, however, the controller reinforces both negatively and positively, so that leaving the situation may also be punished by a reduction in positive reinforcement. Positive reinforcement, however, will generally enhance the tendency to remain in the situation where the positive reinforcement occurs. In the case of extinction of behavior maintained by positive reinforcement, the likelihood of the controlled individual remaining in the situation in which his behavior is being extinguished would depend upon the number of other segments of his repertoire which are still being reinforced.

The duration of effect of aversive control is, of course, a function of the particular schedules and orders of magnitude. Under certain kinds of avoidance conditioning, as was discussed earlier, very strong dispositions to action can be maintained for very long periods of time. Behavior maintained by escape from a primary aversive stimulus or a conditioned aversive stimulus becomes weak or nonexistent when the aversive stimuli or the threat of aversive stimuli no longer occur. "When the cat's away, the mice will play." Under appropriate circumstances prolonged effects of aversive control occur, but these are predominantly suppressive effects of aversive stimuli, or relatively infrequent pathologic conditions. Behavior maintained by positive reinforcement exhibits a potentially large extinction curve which will support the behavior for considerable periods of time without reinforcement.

Some of the relative properties of control by positive and negative reinforcement emerge when we compare the way in which a new complex performance is conditioned. As discussed earlier, the way to develop a complex performance is to begin with some form of behavior already in the organism's repertoire. When a variation in the direction of the acquired form is emitted, the reinforcing stimulus, occurring instantly contingent on the specific response, increases its subsequent frequency of occurrence. In the case of positive reinforcement, it is the presentation of a stimulus. When the individual is stably emitting a particular form of the response, the contingency is shifted toward a slightly more complex form in the direction of the required performance. In the case of aversive control, it is necessary for the aversive event to occur periodically in order to provide a basis for the negative reinforcement to occur. This periodic occurrence of the aversive event has direct emotional effects as well as potential conditioned effects by various stimuli which come to function as preaversive stimuli. These emotional effects will disrupt any behavior occurring, including the behaviors related to those being conditioned. In addition, the periodic presentation of the aversive stimulus will be accidentally correlated with various activities of the animal related to the forms being conditioned. If, for any reason, the behavior being conditioned becomes weak, the aversive stimuli must be delivered more frequently, and the depressive effects of the aversive stimulus become intensified as more and more aversive stimuli are delivered. This will in turn weaken the performance further and, consequently, prolong the degree of exposure to the aversive stimuli. Positive reinforcement, on the contrary, has no such indirect effects. Should positive reinforcement be withheld temporarily, the behavior will continue to be emitted depending upon the degree of prior conditioning. Should the behavior become seriously weakened, a single reinforcement would reinstate it. Finally, with aversive control used to shape complex behavior, it is necessary to hold the animal in the conditioning situation either by restraint or by further aversive control involved in punishment for leaving the experimental situation. The converse is true with positive reinforcement, however. When positive reinforcement is arranged frequently, and with optimal schedules of reinforcement, the disposition to remain in the situation and continue behavior will remain very strong.