DOES CONTINGENT REINFORCEMENT STRENGTHEN OPERANT BEHAVIOR?

In Experiment 1, pigeons were trained to peck keys with equal food-reinforcement schedules in components that ended with either noncontingent or contingent transitions to a third component with a five-fold richer schedule. Response rates were higher in the initial component with contingent transitions, but resistance to prefeeding or extinction was not consistently greater. Experiment 2 also included noncontingent or contingent transitions to a signaled period of nonreinforcement. There was no effect of the contingency on transitions to nonreinforcement, but the difference in response rates maintained by contingent versus noncontingent transitions to the richer schedule was replicated. In addition, response rates were higher in components that preceded nonreinforcement than in components that preceded the richer schedule. However, resistance to extinction was greater for noncontingent transitions to the richer schedule than to nonreinforcement, implicating stimulus–reinforcer relations in the determination of resistance to change. Resistance to change was also somewhat greater for noncontingent than for contingent transitions to the richer schedule. The latter result, together with the results of Experiment 1 and related research, suggests that response-contingent reinforcement does not increase resistance to change.     

Contextual Effects in Judgments of Crimes,Criminals, and the Purposes of Sentencing1

Content analyses of crime coverage in the news media (e.g., Graber, 1980) consistently demonstrate the overrepresentation of crimes of violence. It was hypothesized that in addition to direct effects upon members of the public (e.g., leading people to overestimate the number of violent crimes) this would also have several indirect effects. Reading about crimes of high seriousness might lead the public to (a) view other offenses more seriously, (b) regard other offenders more negatively, (c) punish other offenders more severely, and (d) emphasize the importance of retribution as a sentencing goal. Two experiments were conducted, using 90 members of the general public as subjects, to test these hypotheses. In Experiment I, subjects first read a news story about a crime that was of high, medium, or low seriousness. Later they rated an unrelated offender and offense more negatively, and were more punitive in their sentences, if the earlier offense had been very serious. There was equivocal support for the hypothesis that changes in punitiveness are caused by subjects shifting to a punishment-oriented sentencing strategy. Rather, it would appear that harsher penalties resulted from changes in perceptions of offense seriousness. These findings are discussed, as are future research directions.     

Timing light and tone signals in pigeons

Pigeons' ability to time light and tone stimuli was examined in four experiments. In Experiment 1, two groups of pigeons were trained to discriminate between 2- and 8-s durations of lights or tones and then were transferred to reversal or nonreversal discriminations in the alternate modality. Pigeons learned the light discrimination faster than the tone discrimination and showed immediate positive intermodal transfer from tone to light but not from light to tone. In Experiments 2-4, the peak procedure was used to study birds' timing of 15- and 30-s fixed-interval light and tone signals. Peak times on empty trials under baseline conditions closely approximated the length of fixed-interval signals. When pigeons were tested with time-outs and intermodal switches introduced midway through an empty trial, they tended to reset the timing mechanism and begin timing again from 0 s. With both estimation and production procedures, pigeons were less accurate when timing the tone stimuli than when timing the light stimuli. A comparison of these data with data from timing experiments with rats suggests several possible differences in timing processes between pigeons and rats.     

Health Beliefs and Intentions: Predictors of Return Compliance in a Tuberculosis Detection Drive1

A prospective design was employed to study the ability of various factors to predict return compliance in a tuberculosis detection drive. Five hundred fiftythree participants in the drive were asked to complete a questionnaire tapping their views of TB (based on the Health Belief Model) and their intentions to return for the recommended skin test reading. Behavioral intention was found to be an important predictor of return rates, and the inclusion of the HBM variables aided in the classification noncompliers. Practical and theoretical implications of these findings are discussed.     

Conditioned suppression of an avoidance response

A signal followed by shock was presented at irregular intervals during a free-operant avoidance schedule. The effects of this procedure were studied in terms of the rate of unavoided shock in the presence and absence of the signal and the rate of response before and during the signal. Three shock intensities were employed. Response enhancement as well as response suppression were observed; irrespective of changes in responding, shock rates substantially increased during signalled periods compared to non-signalled periods. Shock rates in non-signalled periods were generally higher than during training.     

Causal chunking: memory and inference in ongoing interaction

We propose that people simplify their perceptions of their interactions by organizing them into discrete casual chunks. Once formed, these chunks presumably influence the extent to which people are aware of their influence on others, as well as their impressions of others. We anticipated that people would form self-causal chunks (e.g., my action causes my partner's action) when they possessed an offensive set and other-causal chunks when they possessed a defensive set. We also expected that a self-causal chunking strategy would make salient people's influence on their partners and thereby discourage them from concluding that their partner's behaviors reflected underlying dispositions. In contrast, we anticipated that an other-causal chunking strategy would obscure people's influence on their partners, thereby encouraging them to infer that their partners' behaviors reflected underlying dispositions. We tested these hypotheses by inducing participants to develop either a defensive or an offensive set prior to interacting with another person in a simulated arms race. After the interactions, we assessed the manner in which participants chunked their interactions, as well as their impressions of partners. The results supported our predictions. The implications of these findings for understanding conflict and misunderstanding in interpersonal relations are discussed.