A reason for theoretical terms

The presence of nonobservational vocabulary is shown to be necessary for wide application of a conservative principle of theory revision.Support for this research was provided by the Office of Naval Research under contract No. N00014-87-K-0401. We thank Daniel Andler and Clark Glymour for helpful discussion.     

Using a Conceptually-Based Predictor of Tenure to Select Employees

This paper describes the development and validation of a personnel selection instrument designed to predict employee tenure. The instrument was developed using models of employee turnover, psychodynamic theory, and beliefs regarding the optimal way to advance one's career. Four predictive designs were conducted to validate the instrument. Correlation coefficients ranged from .14 (p < .07) to .28 (p < .05) in predicting tenure.     

Dispositionai Optimism as a Protective Factor in Resisting HIV Exposure in Sexually Active Inner-City Minority Adolescents1

Recent investigations have explored dispositional optimism as a determinant of various health-related behaviors, though such research has been infrequently conducted in populations where pessimism would be expected to be prevalent. The present study examines optimism and unsafe sexual behavior in 230 sexually active inner-city minority adolescents. Findings suggest that dispositional optimism is a protective factor regarding adolescents' intentions to avoid engaging in unsafe sex. Further, the benefits of optimism appear to be explained by those who are more optimistic having higher levels of perceived condom use self-efficacy and stronger negative expectancies toward unsafe sex. Future interventions may need to address optimism in concert with behavioral-specific determinants to increase the probability of reducing unsafe sexual behavior in high-risk populations.     

Influence of the initial projection of the centre of gravity on posturo-kinetic coordination in humans. Application from a horizontal quadrupedal stance during voluntary limb raising

The purpose of the study is to investigate the influence of initial projection of the centre of gravity (CG) on the spatial and temporal organization of the dynamic phenomena accompanying a voluntary movement in humans. From a horizontal quadrupedal stance, ten normal subjects were instructed to raise the right forelimb towards a support target in self paced velocity conditions. Three experimental conditions were tested for which the initial CG projection was either within (C1), at the limits of (C2) or outside the supporting triangle (C3). The results showed that vertical force variations on the four supports always preceded the first vertical displacement of the right wrist (onset of the movement). From C1 to C3, the duration of these anticipatory dynamic phenomena increased enabling an adjustment of the CG position such that equilibrium constraints were fulfilled. For all conditions, the acceleration peak of the CG occurred prior to the onset of movement and from C1 to C3, its magnitude increased in a single direction of the horizontal plane. For each condition, the load transfer was directed to the left forelimb and the right hindlimb (diagonal strategy) and reached a maximal value at the time of lift-off. With respect to this moment, the onset of the movement occurred increasingly early from C1 to C3. These results suggest that contribution of peripheral cues to postural control is more important, when the requirements of horizontal CG displacement increase.     

Reaction-anticipation transitions in human perception-action patterns

We investigated the hypothesis that reaction and anticipation in human perceptual-motor performance are two coordinative modes of a single pattern-forming dynamical system, rather than separate behaviors. Subjects coordinated the onset of finger flexions with visual metronome flashes in each of three patterns: reactive, synchronized, or syncopated. The stimulus frequency was progressively increased (0.125–1.375 Hz) or decreased (1.375-0.125 Hz) in small steps (0.125 Hz) every 10 cycles. We observed qualitative transitions in both the time interval between stimulus and corresponding action (Δt) and their relative phase (ø) at critical values of the stimulus frequency, corresponding to changes from ‘reactive-to-anticipatory’ and ‘anticipatory-to-reactive’ performance. Such transitions provide evidence of a single, multifunctional system, which can be adequately described by the dynamics of collective variables characterizing the respective perception-action patterns.     

Is fluency free-operant response-response chaining?

This article briefly reviews behavioral fluency and its 10 products. Fluency development requires three of the four free-operant freedoms: the freedom to present stimuli at the learner's rhythm, the freedom to form the response, and the freedom to speed at the learner's maximum frequency. The article closes with several suggestions that fluent performing is really operant response-response (R-R) chaining, and recommends further controlled laboratory research on free-operant R-R chaining.     

Psychopathic personality traits and temporal perspective: A test of the short time horizon hypothesis

A number of authors have proposed that psychopathic individuals possess an abnormally constricted time horizon (i.e., foreshortened sense of the future). This hypothesis was tested among 101 undergraduates, who were administered a battery of (1) self-report indices of psychopathic personality traits, antisocial behavior, and normal-range personality traits; (2) self-report indices of time perspective; (3) projective tests of time perspective; and (4) laboratory tasks assessing time estimation and capacity for foresight and impulse control. Measures of psychopathy/antisocial behavior tended to be negatively correlated with several self-report indices assessing preoccupation with the future and with a projective task assessing the frequency of thoughts concerning future events, although only one of the correlations with this latter task was significant. In most cases these correlations were not attributable to the variance shared by measures of psychopathy/antisocial behavior and measures of (low) anxiety-proneness, although several correlations decreased substantially after levels of harmavoidance were controlled. In contrast, measures of psychopathy/antisocial behavior were negligibly correlated with laboratory tasks. These results provide mixed support for the short time horizon hypothesis and suggest that further attention to the role of method factors in investigations of future time perspective is warranted.