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Three rats were trained on a temporally defined avoidance schedule logically similar to a fixed‐interval, limited‐hold positive reinforcement schedule. This avoidance schedule was composed of time periods during which responses had no scheduled consequences alternating with time periods during which a response precluded shock. As with fixed‐interval length and response rate on positive reinforcement schedules, an inverse relationship was obtained between the length of the no‐consequence interval and response rate during the no‐consequence interval. An inverse relationship was also obtained between the length of the no‐consequence interval and the per cent of shocks avoided. A rate increase within the no‐consequence interval, similar to that typically produced by fixed‐interval positive reinforcement procedures, was displayed by one of the rats where the no‐consequence interval was at intermediate values and frequency of shock was relatively high. The introduction of a discriminative stimulus correlated with the avoidance interval produced typical discriminated avoidance behavior as well as alterations in temporal patterning of responses during the no‐consequence interval in the two rats exposed to this procedure. These alterations in temporal patterning disappeared when the discriminative stimulus was removed. The results were consonant with those reported in the literature involving food reinforcement and fixed‐interval, limited‐hold schedules.

Squirrel monkeys were exposed to response‐independent, fixed‐frequency shock that produced biting attack upon a pneumatic hose. Attacks decreased within and across sessions at low intensities and high frequencies of shock, but increased within and across sessions at higher intensities and lower shock frequencies. Stimuli paired with shock, when presented alone, came to produce biting, and stimuli correlated with shock parameters that produced increases in responding within sessions produced similar increases when presented alone. Further experiments showed that continuing exposure to shock also produced lever pressing or chain pulling, with longer shock exposure again producing higher response rates. Whereas biting generally decreased throughout the intershock interval, manual responding generally increased as shock time approached, but immediately before shock was often suppressed. Following shock, biting attack predominated over manual behavior. The results suggest a possible explanation for the extreme resistance of avoidance behavior to extinction, and may also partially explain the persistence of responding during schedules of response‐produced shock. Relationships of the present findings to naturalistic observations of relations between fleeing, freezing, and fighting performances are discussed.

A nonsense word was paired with reinforcement to determine if pairing affected emission of a response that produced the word in the signalled absence of reinforcement. Children were trained on a multiple schedule that consisted of a reinforcement component, conditioned reinforcement component, and control component, each set of contingencies being signalled by a different colored light. In the primary reinforcement component, lever presses produced reinforcers which, in some phases, were paired with a word. In the other two components, lever presses were not reinforced and a button was made accessible. Button presses in the conditioned reinforcement component produced the word to be (or being) paired, e.g., “yafeh”, while button presses in the control component produced another word, e.g., “grunch”. Button pressing increased when one of the words was being paired and decreased when pairing was discontinued, but directly related rate changes occurred also in the control component. The order of components was shown to be a contributing variable.

Positive reinforcement, physical guidance, and fading procedures were used to teach two severely retarded children motor responses to a variety of verbal instructions. Subjects' responses to one set of instructions provided the focus for the training procedures. Their responses to a second set of instructions were used to assess the generalized effects of training. The frequency of responses to both sets of instructions was evaluated during Baseline 1, Training 1, Baseline 2, and Training 2 periods. During the training periods, this evaluation was made after the daily training sessions when no training procedures were in effect. Results indicated that the subjects showed pronounced increases in instruction‐following behaviors (both trained and untrained) during training periods with decreases in such behavior occurring during the Baseline 2 period. The general findings demonstrate the applicability of the training procedures for producing and maintaining instruction‐following behaviors in severely retarded children and for facilitating appropriate responding to instructions not directly involved in training.

Two variable‐interval 3‐min schedules functioned concurrently to arrange reinforcement of a pigeon's pecks on a single key, the main key. Each schedule was associated with a distinct color of the main key; a response on a second key alternated the color and schedule assignment of the main key. A changeover delay, a period of time following schedule and key‐color alternation during which reinforcement of responding on the main key could not occur, was arranged with equal or with unequal durations for the two directions of alternation. Durations were varied from 0.33 sec to 27 sec, in addition to no delay. With equal delays for the two directions of alternation, the pigeon alternated the schedules less often the larger the delay duration. When the delays in the two directions of alternation were unequal, it could be shown that alternation of the schedules was reduced both by a delay just incurred by the last alternation and by a. delay to be incurred by the next. The latter delay was more potent in reducing the frequency of alternations.

Fighting responses were elicited in pairs of rats by shocks over a period of 46 days. During certain blocks of these days, “punishing” shocks were made contingent on the shock‐elicited fights. Fighting frequency was reduced as a direct function of the intensity of the contingent shocks. Fighting frequency recovered completely when contingent shocks were removed.

Responding produced food according to a fixed‐ratio schedule while the prevailing key‐color alternated between red and blue. Stimulus durations were varied until a period was found that maintained equal rates of responding in the presence of both colors. Then, food presentation was discontinued in the presence of one stimulus and made dependent on not responding in the presence of the other. Food presentation dependent on not responding reduced the rate of responding faster than did extinction. Spontaneous recovery occurred only during the stimulus correlated with extinction.

Twenty‐eight nursing staff members treated, by operant methods, a simulated headbanging patient. They were randomly assigned to four experimental conditions, involving improvement versus non‐improvement of the “patient” and promise of reward versus no promise of reward. The promise of reward significantly improved accuracy of treatment. Improvement of the patient, however, did not improve accuracy.

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