Читать книгу Introduction to Abnormal Child and Adolescent Psychology - Robert Weis - Страница 94

Whereas classical conditioning occurs when children associate two stimuli together in time, operant conditioning occurs when children associate an action with a consequence in the environment. Operant conditioning is based on the notion that the consequences of our actions determine the likelihood that the actions will be repeated.

If the consequences of our actions increase the likelihood that we will repeat the behavior in the future, these consequences have reinforced our behavior. Reinforcement can be positive or negative. Positive reinforcement occurs when an individual is presented with a stimulus that increases the likelihood of behavior. For example, a father might give his daughter ice cream after she eats her vegetables at dinner. If the presentation of ice cream following the meal increases the likelihood that the girl eats her vegetables in the future, we say that the ice cream positively reinforced the child’s eating.

Many people mistakenly believe that the adjective “positive” in the term positive reinforcement refers to the pleasantness of the reinforcer. In fact, the term positive simply refers to the fact that the stimulus is presented to the individual. Some presumably pleasant stimuli are not positively reinforcing to all children. For example, providing a 2-year-old with one piece of candy for using the toilet may increase the likelihood that he will use the toilet in the future. However, providing one piece of candy to a 14-year-old for completing his math homework will likely not increase the likelihood that he will complete his math homework in the future.

Additionally, some presumably unpleasant stimuli can be positively reinforcing. For example, a teacher may reprimand her student for disrupting class. If the teacher’s reprimand results in an increase in the student’s disruptive behavior, the teacher’s behavior is positively reinforcing, no matter how aversive it appears.

Negative reinforcement occurs when the withdrawal or avoidance of a stimulus increases the likelihood of behavior. For example, a father might allow his daughter to leave the dinner table only after she finishes her vegetables. If escaping the dinner table by eating vegetables increases the likelihood that the girl eats her vegetables in the future, we say that the father’s actions negatively reinforced the child’s eating.

Negative reinforcement often underlies childhood behavior problems. For example, a mother might ask her son to turn off Netflix and clean his room. The son might ignore his mother because he prefers to watch his favorite program. The mother might withdraw her request and clean her son’s room herself. If the mother’s behavior (i.e., withdrawal of her request) increases the likelihood that her son will ignore her requests in the future, we say that her actions are negatively reinforcing his disobedience. She is teaching him to ignore her requests.

In contrast to reinforcement, punishment always decreases the probability of future behavior. There are two types of punishment: positive and negative. Positive punishment involves a stimulus presentation that decreases the likelihood of behavior. For example, a mother might spank her son for his disobedience. If spanking results in a decrease in her child’s defiance, then it is a form of positive punishment. Negative punishment involves avoidance or removal of a stimulus that decreases the likelihood of behavior. For example, a teacher might remove a child from a desirable classroom activity following his disruptive behavior in class. If the teacher’s actions result in a decrease in the student’s disruptive behavior, then the teacher’s behavior was a form of negative punishment (Table 2.2).

Clinicians prefer to use reinforcement, instead of punishment, to correct behavior problems. In some cases, however, punishment can be used therapeutically. For example, a therapist might teach a parent to use positive punishment to correct her son’s bed-wetting. Each time the boy wets the bed, the parent might require the boy to perform a series of actions designed to correct the problem behavior. These actions might include stripping the bed, taking the bedding to the washing machine, helping to start the wash, putting on new sheets, and sitting on the toilet. Similarly, a therapist might teach a parent to use time-out as a form of negative punishment for her disruptive preschooler. Time-out involves removing the child from all potentially reinforcing stimuli for a period of time, in an attempt to decrease the child’s defiance. The child might be required to sit in a special chair for 3 minutes with no access to toys, television, or other stimuli.

Table 2.2

Note: Reinforcement increases future behavior; punishment decreases it.