Relative allocation on concurrent schedules can depend on schedule parameters when behavioral parameters are constant

We develop a simple model of switching between the initial links of a concurrent-chain procedure. Behavior is determined by four parameters μ₁, μ₂, q₁, and q₂. The first two are the basic rates of switching from Schedule 1 and Schedule 2, respectively. The second two are the probabilities of leaving Schedule 1 and Schedule 2 after the corresponding terminal link has been completed. We show that for fixed values of these four parameters, the relative allocation on the initial links may change as a result of changes in initial-link schedules. The effect can be quite large if the switching rates are low. An implication is that relative allocation is not necessarily a good measure of behavior.     

The operant conditioning of response variability: Free-operant versus discrete-response procedures

The operant conditioning of response variability under free-operant and discrete-response procedures was investigated. Two pigeons received food only if their pattern of four pecks on two response keys differed from the patterns emitted on the two immediately preceding trials. Under the free-operant procedure, the keys remained illuminated and operative throughout each trial. There was little variability in the response patterns that resulted, and the pigeons received fewer than one third of the available reinforcers. Under the discrete-response procedure, a brief timeout period followed each response. Variability increased under this procedure, and the pigeons obtained three fourths of the available reinforcers. Previous successes and failures to produce response variability may have been due to the use or failure to use, respectively, a discrete-response procedure. Respondent effects inherent in the free-operant procedure may encourage the development of response stereotypy and, in turn, prevent the development of response variability.     

The psychology of self-esteem: Promise or peril?

The psychology of self-esteem bypasses consequential issues of everyday behavior and moral responsibility in favor of pursuing a global goal of enhanced self-esteem on the assumption that happiness, success, and responsible behavior will automatically follow. The goal is vague and ways of achieving it are confused and conflicting. Greater attention to concrete tasks and challenges and sensitivity to moral issues could help make therapy more clear, effective, and socially useful.     

Control of responding during stimuli that precede transitions in reinforcement frequency

Pigeons' responses were reinforced on a variant of a mixed variable-interval extinction schedule of reinforcement in which the transition to the higher reinforcement rate was signaled by a trace stimulus projected on the response key prior to the onset of the component correlated with food delivery. In the first of two experiments, the duration of the trace stimulus preceding the component correlated with food delivery was varied from 1.5 to 50.0 s and in the second experiment, the reinforcement frequency in the same component was varied from 10 to 60 reinforcers per hour. Pigeons pecked at the trace stimulus preceding the onset of the component correlated with food delivery even though responding was not reinforced in its presence and only one of the changes in reinforcement rate (i.e., from extinction to reinforcement) was signaled. The rate of pecking during the trace stimulus was a function of its duration but not of the reinforcement frequency in the following component. Higher rates generally occurred at the shorter trace-stimulus durations. Component responding following the offset of the trace stimulus was under discriminative control of the trace stimulus whether or not responding occurred in the presence of the trace stimulus.     

Margaret Mead and behavioral scientists in World War II: problems in responsibility, truth, and effectiveness

In World War II, Margaret Mead and her behavioral science colleagues actively applied their science to the American war effort on issues such as morale, food habits, psychological warfare, and the evacuation of Japanese-Americans from the West Coast. Mead's participation or lack of participation in these activities, and her varying enthusiasms and misgivings about them, raise fundamental issues about the responsibility of behavioral scientists to warn the public against dangerous policies, as well as the ethics of behavioral scientists participating in deceitful psychological warfare and the extent of their effectiveness in contributing to public policymaking.     

In Hall's shadow: Edmund Clark Sanford (1859-1924)

Edmund C. Sanford of Clark University had earned a reputation by the end of the nineteenth century as a leading American psychologist. He had written the first training manual for experimental psychology and created numerous pieces of laboratory apparatus. He was also editor of the American Journal of Psychology and a charter member of the American Psychological Association. Although his peers elected him to the presidency of the APA in 1902, his standing had already begun to decline. Sanford's impact on early American experimental psychology is documented and the reasons for his reduced status as American psychology grew in the early years of the new century are explored.