Sensory superstition on multiple interval schedules.

Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food.     

Choice and multiple reinforcers

Pigeons chose between equivalent two-component mixed and multiple terminal-link schedules of reinforcement in the concurrent-chains procedure. The pigeons preferred the multiple schedule over the mixed when the components of the compound schedules were differentiated in terms of density of reinforcement, but the pigeons were indifferent when the components were differentiated in terms of number of reinforcers per cycle. Taken together, these results indicate that a local variable, the interval to the first reinforcer, but not a molar variable, the number of reinforcers, was sufficient to differentiate the components and thereby evoke preference.     

On the self-perpetuating nature of stereotypes about women and men

An experiment was conducted to investigate an interpersonal process that contributes to the perpetuation of stereotyped beliefs about women and men. Male-female pairs of unacquainted individuals interacted to negotiate a division of labor on a series of work-like tasks (that differed in their sex-role connotations) in a situation that permitted control over the information that male perceivers received about the apparent sex of female targets. The perceivers' beliefs about the sex of their targets initiated a chain of events that resulted in targets providing behavioral confirmation for perceivers' beliefs about their sex. Targets believed by perceivers to be male chose tasks relatively masculine in nature, and targets believed by perceivers to be female chose tasks relatively feminine in nature. Although this behavioral confirmation effect was initially elicited as reactions to overtures made by perceivers, it persevered so that eventually targets came to initiate behaviors “appropriate” to the sex with which they had been labeled by perceivers. The specific roles of perceivers and targets in the behavioral confirmation process are examined. Implications of these findings for the perpetuation of stereotyped beliefs about the sexes are discussed.     

Changes in a multiple-response repertoire during response-contingent punishment and response restriction: Sequential relationships

A multiple-response baseline of four activities was established using gerbils as subjects. When one of the baseline responses was punished (Experiment 1) or restricted (Experiments 2 and 3), only the most probable of the alternative baseline responses increased. The response most likely to follow the punished or restricted responses during baseline sessions was also suppressed during subsequent punishment or response-restriction treatment.     

Comparison of observational recordings in vivo, via mirror, and via television

Simultaneous observational recordings were made in vivo, via an observation mirror, and via closed circuit television. Three of nine observers had extensive experience recording behavior in vivo; three had extensive experience recording behavior via mirror; and three had extensive experience recording via television. Observers recorded nine categories of disruptive behavior for children in a special class setting. Frequencies of behavior recorded in vivo, via mirror, and via television differed significantly for only one category, vocalization. There were no significant main effects or interactions involving the observers' previous experience. Occurrence reliability coefficients computed within and between media demonstrated the similarity of observer agreement in all three media. Data collection procedures using an observational mirror or closed circuit television appear to be reasonable alternatives to in vivo observation in circumstances similar to those in the present study.     

Reward and number of choices in children's probability learning: An attempt to reconcile conflicting findings

Five event schedules (75:0, 75:25, 75:0:0, 72:25:0, 75:12.5:12.5) were examined in a size discrimination task with penny rewards and plastic token markers. The subjects were 100 fourth graders (mean age = 9.4 years) and 100 undergraduates of both sexes. Whether or not the event probabilities summed to unity proved to be a more important determiner of terminal performance than the number of response alternatives in the task (p < .01). Females maximized more than males (p < .001) and college students more than fourth graders (p < .001). Greater maximization was exhibited by fourth graders in the reward condition (p < .01). These reward effects appeared to be more consistent with a detrimental-effects-of-reward interpretation than either utility or expectancy interpretations.     

An experimental analysis of the effects of d-amphetamine and cocaine on the acquisition and performance of response chains in monkeys.

In one component of a multiple schedule of food presentation, monkeys acquired a different four-response chain each session by responding sequentially on three keys in the presence of four geometric forms (learning). In the other component, the four-response chain was the same each session (performance). Both d-amphetamine and cocaine, at the higher doses, disrupted the behavior in the learning component; the overall response rate decreased, the overall accuracy was impaired (i.e., percent errors increased), and there was less within-session error reduction. The performance component was generally less sensitive than the learning component to the disruptive effects of both drugs on rate and accuracy. After pre-feeding or during an extended session, the response rate decreased in both components, but accuracy was generally unaffected. When the four discriminative stimuli in both components were removed, the behavior was disrupted to a greater extent in the performance component. The disruptive effects of both drugs on behavior in the learning component were attenuated when the drugs were administered during the session after the response chain had been acquired. It was concluded that the greater sensitivity of the learning component to disruptive drug effects is related to the relatively weak stimulus control and/or the lower rate of reinforcement associated with that component.     

Reducing residential electrical energy use: payments, information, and feedback

Monetary payments, energy information, and daily feedback on consumption were employed to reduce electricity use in four units of a university student housing complex. A combined multiple-baseline and withdrawal design permitted both within- and between-unit comparisons. Payments produced immediate and substantial reductions in consumption in all units, even when the magnitude of the payments was reduced considerably. Feedback also produced reductions, but information about ways to conserve and about the cost of using various appliances did not. It was also found that, in general, payments combined with either information or feedback produced no greater effect than payments alone.