Superstitious behavior in humans

Twenty undergraduate students were exposed to single response-independent schedules of reinforcer presentation, fixed-time or variable-time, each with values of 30 and 60 s. The reinforcer was a point on a counter accompanied by a red lamp and a brief buzzer. Three color signals were presented, without consistent relation to reinforcer or to the subjects' behavior. Three large levers were available, but the subjects were not asked to perform any particular behavior. Three of the 20 subjects developed persistent superstitious behavior. One engaged in a pattern of lever-pulling responses that consisted of long pulls after a few short pulls; the second touched many things in the experimental booth; the third showed biased responding called sensory superstition. However, most subjects did not show consistent superstitious behavior. Reinforcers can operate effectively on human behavior even in the absence of a response-reinforcer contingency and can, in some cases, shape stable superstitious patterns. However, superstitious behavior is not a consistent outcome of exposure of human subjects to response-independent reinforcer deliveries.     

Collateral effects of response blocking during the treatment of stereotypic behavior

The collateral effects of response blocking were evaluated while treating stereotypic behavior in a woman diagnosed with autism. Blocking stereotypic behavior (head and tooth capping) was associated with decreases in leisure-item interaction and increases in another stereotypic response (hand wringing). Results suggested that the reduction in item interaction was due to adventitious punishment. Prompts to access an alternative source of reinforcement attenuated the side effects somewhat, but results suggested that the undesirable effects of response blocking may be fairly durable.     

Collateral behavior of the pigeon during conditioned suppression of key pecking

Ethological recording procedures measured collateral behavior in pigeons whose key-pecking performance was suppressed during a tone that ended with unavoidable electric shock. Independent recordings of gross behavior were made by two observers throughout 60-sec intervals immediately before, during, and after tone presentation. Results indicated significant reductions in the frequency of collateral movements and an increase in the time between successive movements during tone presentations. These effects were observed in all subjects, despite differences in the sequential patterns of behavior. Only partial recovery of the behavior evidenced before tone presentation was found during a 60-sec interval following shock. It was concluded that conditioned suppression procedures caused the bird to “freeze” during tone presentation and in this fashion produced a general inhibitory effect on ongoing overt activity, including key pecking.     

The neurotic paradox and self-punitive behavior in humans

Human subjects learned a key-pressing response in order to avoid or escape shock. The reinforcement contingencies were then changed to punishment or to regular nonpunished extinction. The locus of shock onset and offset was systematically varied during the punishment phase. More subjects reported awarencess of the change in the nonpunished extinction group. By inference, the punished groups responded more, and thus the results appear analogous to animal studies on vicious circle, self-punitive responding. Discriminability of change from acquisition to extinction appeared to affect detection of the change.     

Discriminative control of punished stereotyped behavior in humans

The purpose of this experiment was to establish discriminative control of responding by an antecedent stimulus using differential punishment because the results of past studies on this topic have been mixed. Three adults with mental retardation who exhibited stereotypy not maintained by social consequences (i.e., automatic reinforcement) participated. For each subject, stereotypy occurred frequently in the presence of a stimulus correlated with nonpunishment of stereotypy and rarely, if ever, in the presence of a stimulus correlated with punishment of stereotypy. Latency measures showed that the antecedent stimulus correlated with punishment served as the discriminative stimulus for the suppression of stereotypy. These results are important insofar as they show that discriminative control by an antecedent stimulus develops with punishment, and because it sometimes may be desirable to establish such control of socially inappropriate behavior.     

A telemetry system for measuring chewing behavior in humans

A system is described for detecting and recording human chewing behavior. A small transmitter mounted in the side frame of eyeglasses was used to detect muscle movement associated with chewing. The transmitter signal was received and converted to a direct-current voltage which varied at a rate proportional to the S's chewing movement. Exploratory data are presented which suggest that individuals chew at about the same rate per second, but vary in the total number of chews emitted to consume the same amount of foodstuff.     

Self-punitive behavior in humans: Effects of a self-fulfilling prophecy

Human subjects were exposed to contingencies which programmed aversive tones (100 db). Two types of contingencies were employed: self-confirming (i.e., self-fulfilling prophecies), in which the aversive tone was occasioned by the prediction it was about to occur; and self-disconfirming, in which the tone was probable when subjects predicted it would not occur. Experiments 1 and 2 used a modified classical conditioning paradigm, and demonstrated that a self-confirming contingency maintained reliable self-punitive responding, i.e., subjects consistently predicted and therefore obtained tones on every trial. Subjects in Experiment 3 were instructed to express predictions continuously throughout four sessions to ensure adequate sampling of the various predictions. Subjects exposed to a self-disconfirming contnngency reliably evidenced awareness of the contingency in effect (judged by answers on a postexperimental questionnaire), whereas subjects exposed to a self-confirming contingency failed to show effective avoidance behavior or contingency awareness. Experiment 4 investigated free-operant self-punitive behavior, utilizing a single prediction response button, which subjects depressed repeatedly. Subjects were exposed to either periodic or aperiodic punishment schedules over as many as four sessions. In general, more persistent self-punitive responding was found in the groups receiving periodic punishment. The results from the four experiments show that self-confirming contingencies can effectively prolong self-punitive responding in human subjects. The findings are consistent with a blocking interpretation of self-punitive behavior, which asserts that when an aversive event is already predicted by stimuli in the situation (including temporal cues), the association between a response and punishment is impaired, and self-punitive responding is likely to be maintained. An integration of human and animal self-punitive research is proposed.     

The effect of punishment on free-operant choice behavior in humans

During Phase I, three female human subjects pressed a button for monetary reinforcement in five variable-interval schedules specifying different frequencies of reinforcement. On alternate days, responding was also punished (by subtracting money) according to a variable-ratio 34 schedule. In the absence of punishment, response rates conformed to Herrnstein's equation for single variable-interval schedules. Punishment suppressed responding at all frequencies of reinforcement. This was reflected in a change in the values of both constants in Herrnstein's equation: the value of the theoretical maximum response-rate parameter was reduced, and the parameter describing the reinforcement frequency corresponding to the half-maximal response rate was elevated. During Phase II, the same five schedules (A) were in operation (without punishment), but in addition, a concurrent variable-interval schedule (B) of standard reinforcement frequency was introduced. On alternate days, responding in Component B was punished according to a variable-ratio 34 schedule. In the absence of punishment, absolute response rates conformed to equations proposed by Herrnstein to describe performance in concurrent schedules; the ratios of the response rates in the two components and the ratios of the times spent in the two components conformed to the Matching Law. When responding in Component B was punished, response rates in Component B were reduced and those in Component A were elevated, these changes being reflected in distortions of the matching relationship.     

Collateral effects of behavioral parent training on families of children with developmental disabilities and behavior disorders

We evaluated collateral effects of behavioral parent training (BPT) on families with children who have developmental disabilities and behavior disorders. We compared 18 BPT graduates to 18 similar families waiting for service. The BPT graduates reported significantly less (i) child behavior problems, (ii) disruption to child and family quality of life due to child problem behavior, and (iii) stress related to limits on family opportunities and child physical limitations, up to 5 years after discharge. On a self‐efficacy scale, the graduates reported being more effective child behavior change agents in not only stopping child problem behavior, but also in preventing new occurrences and teaching the child appropriate behavior. These results suggest that BPT has persistent beneficial effects on children and parents. The findings reflect the program's focus on teaching parents how to use functional assessment derived positive teaching strategies to replace child problem behavior. Copyright © 2002 John Wiley & Sons, Ltd.     

Infant transfer behavior in humans: A note on the exploitation of young

Human infant transfers filmed in West New Guinea and stored in the archives of Max-Planck Geselschaft are formally described and analyzed relative to reports of similar behavior from nonhuman primates in laboratory and field studies. Motor patterns directed from one individual to another were discriminated and grouped into five categories of behavior ordered according to their relative likelihoods of “damaging aggression” [Fagen, American Naturalist, 115:858–869, 1980]. Transfers generally occurred between two females of different reproductive conditions. Most interactions were directed from the holder of the infant to the infant, demonstrating that the infant is the recipient of most nondamaging as well as potentially damaging behavior. While transfers are characterized by “aggressive restraint,” the least damaging behavior is most likely to precede a transfer and may function to prolong the relative duration of infant holding. Behavior with a relatively high likelihood of damage to the infant by the infant holder is as likely to occur before as after transfer, suggesting that infant transfer behavior in this human society reflects competitive interactions among adult females.     

The social dimension of stress reactivity: acute stress increases prosocial behavior in humans

Psychosocial stress precipitates a wide spectrum of diseases with major public-health significance. The fight-or-flight response is generally regarded as the prototypic human stress response, both physiologically and behaviorally. Given that having positive social interactions before being exposed to acute stress plays a preeminent role in helping individuals control their stress response, engaging in prosocial behavior in response to stress (tend-and-befriend) might also be a protective pattern. Little is known, however, about the immediate social responses following stress in humans. Here we show that participants who experienced acute social stress, induced by a standardized laboratory stressor, engaged in substantially more prosocial behavior (trust, trustworthiness, and sharing) compared with participants in a control condition, who did not experience socioevaluative threat. These effects were highly specific: Stress did not affect the readiness to exhibit antisocial behavior or to bear nonsocial risks. These results show that stress triggers social approach behavior, which operates as a potent stress-buffering strategy in humans, thereby providing evidence for the tend-and-befriend hypothesis.     

Effects of reinforcement rate and reinforcer magnitude on choice behavior of humans

Two experiments with human subjects investigated the effects of rate of reinforcement and reinforcer magnitude upon choice. In Experiment 1, each of five subjects responded on four concurrent variable-interval schedules. In contrast to previous studies using non-human organisms, relative response rate did not closely match relative rate of reinforcement. Discrepancies ranged from 0.03 to 0.43 (mean equal to 0.19). Similar discrepancies were found between relative amount of time spent responding on each schedule and the corresponding relative rates of reinforcement. In Experiment 2, in which reinforcer magnitude was varied for each of five subjects, similar discrepancies ranging from 0.05 to 0.50 (mean equal to 0.21), were found between relative response rate and relative proportion of reinforcers received. In both experiments, changeover rates were lower on the long-interval concurrent schedules than on the short-interval ones. The results suggest that simple application of previous generalizations regarding the effects of reinforcement rate and reinforcer magnitude on choice for variable-interval schedules does not accurately describe human behavior in a simple laboratory situation.     

Effect of variable-interval punishment on the behavior of humans in variable-interval schedules of monetary reinforcement

One male and three female human subjects pressed a button for monetary reinforcement under a range of variable-interval schedules specifying different frequencies of reinforcement. On alternate days, responding was also punished (by subtraction of money) according to a variable-interval 170-second schedule. In the absence of punishment, the rate of responding was an increasing negatively accelerated function of reinforcement frequency, as predicted by Herrnstein's equation. The effect of the punishment schedule was to suppress responding under lower frequencies of reinforcement; responding under higher reinforcement frequencies was much less affected. This was reflected in an increase in the value of K_H (the constant expressing the reinforcement frequency corresponding to the half-maximal response rate), whereas there was no significant change in the value of R_max (the constant expressing the maximum response rate). Previous results had shown that variable-ratio punishment resulted in a change in the values of both constants (Bradshaw, Szabadi, and Bevan, 1977). The results of the present study were consistent with the concept that the suppressive effects of punishment on responding depend on the nature of the punishment schedule.