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The attendance rates of welfare recipients at self‐help group meetings was compared when supplementary reinforcement was given for attending and when it was not. Reinforcers included donated items, such as clothing and household goods, and information about welfare services. It was found that the attendance at meetings averaged three recipients per meeting without reinforcement and 15 recipients per meeting with reinforcement. There was evidence that attendance was associated with participation in other self‐help activities. It was concluded that practical forms of reinforcement can be found to maintain the participation of severely disadvantaged populations in self‐help groups.

After training on a multiple variable‐interval variable‐interval schedule of reinforcement, each response in one component of the schedule was followed by a brief electric shock. When the rate of punished responses stabilized, the frequency of reinforcement in the other component was first decreased and then increased from the baseline frequency. The effects of these manipulations were consistent with reports of interactions in multiple schedules involving only unpunished behavior, i.e., the rate of punished responses increased with a higher relative frequency of reinforcement in the punishment component and decreased with a lower relative frequency of reinforcement in that component. The relevance of such findings to a further generality of behavioral contrast effects is discussed.

Squirrel monkeys, initially trained under a schedule of electric shock postponement and then under fixed‐interval schedules of electric shock presentation, were studied under multiple fixed‐interval fixed‐ratio and under fixed‐ratio schedules of shock presentation. Under the fixed‐interval (10‐min) component of the multiple schedule, a pause was followed by a gradual increase in responding to a rate maintained until shock presentation; under the fixed‐ratio (3‐, 10‐, or 30‐response) component of the multiple schedule, a brief pause was typically followed by a relatively high and uniform rate of responding until shock was presented. When the 60‐sec timeout periods, which usually followed shock presentation, were eliminated from the multiple schedule for one monkey, responding was only transiently affected. In the one monkey studied, responding was maintained under a fixed‐ratio schedule alone (with timeout periods), but rates of responding were lower than under the fixed‐ratio component of the multiple schedule. Characteristic patterns of responding, similar to those engendered under schedules of food presentation or shock termination, can be maintained under fixed‐ratio schedules of shock presentation; further, patterns of responding can be controlled by discriminative stimuli in multiple schedules.

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Resumo não informado pela fonte indexada.

Pigeons responding for food on fixed‐ratio reinforcement schedules attacked live target birds when the ratio value was increased, but not when the value was decreased. The frequency of attacks peaked several days after ratio value change, and then gradually decreased to an original level.

The collateral water intake of albino rats was measured when the inter‐pellet intervals in fixed‐ratio and fixed‐time schedules were equated. Fixed‐ratio and fixed‐time inter‐pellet intervals were equated by dividing the average fixed‐ratio session time of each subject by 150 (food pellets). The average inter‐pellet interval obtained then defined the subsequent fixed‐time schedule for each individual subject. Shifts to fixed‐time schedules followed the completion of each fixed‐ratio 20, 40, and 80 schedule. This procedure permitted an assessment of the extent to which excessive collateral drinking was associated with inter‐pellet interval length or adventitious food reinforcement. For both the fixed‐ratio and fixed‐time schedules, drinking progressively increased as a function of increasing the duration of the inter‐pellet interval and was a post‐pellet event under the control of variables other than adventitious food reinforcement.

Head‐banging, a common phenomenon among the mentally retarded, was shaped, brought under stimulus control, extinguished, and re‐established in two monkeys through reinforcement and discrimination procedures of operant conditioning. The behavior was stable and led to lacerations, a condition that qualifies head‐banging as self‐injurious. The principles of the analysis of behavior used here may well be of value in the etiology and treatment of some human head‐banging.

Pigeons were trained to depress a lever to avoid electric shock under free‐operant avoidance schedules without a warning signal, or with a warning signal that could be terminated only by a response. Most birds in the signalled avoidance procedure terminated more than 50% of the warning signals before shock. In the unsignalled avoidance procedure, several birds formed a temporal discrimination and received relatively few shocks; other birds responded only in post‐shock bursts, and received many more shocks.

Several experiments exploring the effects of certain behavioral procedures were performed on a psychiatric ward for delinquent soldiers. Within the context of a point economy, the behavioral procedures were examined for their applicability to this patient group in a hospital‐ward setting. The following procedures were studied: (1) use of points as consequences for specific behaviors compared with demonstration of “model” behavior by a ward officer; (2) punishment by a point‐fine to control undesired behavior; (3) use of a chaining‐type reinforcement contingency to increase desired behavior; (4) differential reinforcement of the individual versus the group to increase the frequency of a verbal performance; and (5) reinforcement of reports of personal problems versus impersonal problems.