Testing the dimensionality of the self-consciousness scales

The self-consciousness scale of Fenigstein, Scheier, and Buss (1975) was subjected to internal and external consistency tests based on the classical test theory model. The scale was found to have five underlying dimensions: two for private self-consciousness (viz., self-reflectiveness and internal state awareness), two for public self-consciousness, and one for social anxiety. The confirmatory factor analysis procedures employed by Burnkrant and Page (1984) are shown to be fallible as indicators of unidimensionality. Theoretical implications of newly identified dimensions in the public self-consciousness subscale are discussed.     

Invariance in the MMPI's component structure

Bernstein and Garbin (1985b) suggested that the Minnesota Multiphasic Personality Inventory's major clinical scales (excluding Scales ? and 5) can be approximated by an oblique three-component structure: (a) Profile Elevation, (b) Test-taking Attitudes, and (c) Optimism-Pessimism, collectively termed the salient weight model. In this study, we found that both this model and the MMPI's principal component structure remain invariant across race, sex, and, as previously noted, context of testing (job applicants vs. inmates in correctional institutions). We further noted that several alternative definitions of Profile Elevation provide equally satisfactory representation of the relations among the scales. This factor invariance is necessary, but not sufficient, for the MMPI to be viewed as unbiased.     

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.     

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.     

Malthus's Essay on Population: the facts of "super-growth" and the rhetoric of scientific persuasion

For the Malthusian theory of population to be accepted as "scientific," it was essential that the theory be established on wide empirical evidence. A close examination of the "facts" provided by Malthus, however, shows that many of his crucial facts are based on distortions of the available evidence. Malthus was probably aware of much of this weakness, but for rhetorical reasons he persisted with the sandy empirical foundations from which he began.