Three methods of developing MMPI taxonomies of sexual offenders

In a sample of 261 state hospital sexual offenders, Minnesota Multiphasic Personality Inventory (MMPI) profiles did not differ for offenders with adult victims versus offenders with child victims when offender age was controlled. MMPI 2-point analyses for the whole sample revealed five common codes that were independent of victim maturity. The sample was randomly divided in half and subjected to a cluster-analytic procedure which revealed two MMPI clusters. The first cluster was unelevated, with Scale 4 as its high point. The second cluster had multiple elevations, with Scales 8, 4, 2, and 7 as the highest scales. These clusters were replicated in a cluster analysis of the second half of the sample. However, when the sample was recombined, the two clusters were not externally validated basis on demographic and criminological variables. The results suggest that common psychological variables among sexual offenders may have more discriminative value than victim maturity in developing sexual offender taxonomies.     

Detecting fake-good and fake-bad MMPI-2 profiles

This study examined the extent to which the validity scales of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) could identify subjects who were faking bad or faking good and differentiate between psychiatric patients and normal subjects who were faking bad. Subjects were 106 undergraduate college students and 50 psychiatric patients. Results indicate that the mean profiles and optimal cutoff scores resembled those previously reported for the original MMPI. Accurate identification of persons who were faking bad or faking good was achieved. It was possible to differentiate between the psychiatric patients and normal persons who were faking bad, but different cutoff scores were needed to differentiate between normals taking the test under standard instructions and those instructed to fake bad. Optimal cutoff scores were suggested.     

To be and not to be: Dialectical tense logic

The paper concerns time, change and contradiction, and is in three parts. The first is an analysis of the problem of the instant of change. It is argued that some changes are such that at the instant of change the system is in both the prior and the posterior state. In particular there are some changes from p being true to p being true where a contradiction is realized. The second part of the paper specifies a formal logic which accommodates this possibility. It is a tense logic based on an underlying paraconsistent prepositional logic, the logic of paradox. (See the author's article of the same name Journal of Philosophical Logic 8 (1979).) Soundness and completeness are established, the latter by the canonical model construction, and extensions of the basic system briefly considered. The final part of the paper discusses Leibniz's principle of continuity: Whatever holds up to the limit holds at the limit. It argues that in the context of physical changes this is a very plausible principle. When it is built into the logic of the previous part, it allows a rigorous proof that change entails contradictions. Finally the relation of this to remarks on dialectics by Hegel and Engels is briefly discussed.     

Consistency and error in motor performance

Two response measures that described the consistency and accuracy of motor performance were investigated. A pursuit tracking task was used as the vehicle whereby changes in perceptual motor performance could be monitored over several learning trials. The intra-individual variability of a subject's tracking response was compared to the root mean squared error that was accumulated during each block of trials. Whereas both response measures were sensitive to the changes in performance that occured as a result of practice, neither could be considered sufficiently informative as to be used as a sole indicator of skill acquisition. It appears that both consistency and error measures are needed to describe the subjects' performance as they acquire a perceptual motor skill.     

Second-order ‘fear’ conditioning in humans: Persistence of CR2 following extinction of CR1

Two groups of subjects were given pairings of a slide of a triangle (CS₁) with an aversive loud noise (US). After first-order conditioning a different figure (CS₂⁺) was paired with CS₁, whilst a third figure acted as a non-paired control (CS₂⁰). Conditioned second-order skin conductance responses (SCRs) were established to CS₂⁺ for all subjects who had undergone first-order conditioning. Following second-order conditioning, SCRs to CS₁ were extinguished and CS₂⁺ was subsequently tested for retention of its SCR evoking properties. For the group of subjects who believed they had an avoidance response available during the second-order conditioning phase, CR₂ failed to survive extinction of CR₁. However, for the group of subjects who had no perceived control over US presentation, extinction of cr₁ did not eliminate CR₂. This latter finding is consistent with associative analyses of second-order conditioning in animals and has clinical implications for the treatment of fear-related problems.     

Recognizing faces in and out of context

Two experiments are reported which examined the influence of context on face recognition accuracy for novel and familiar faces respectively. Context was manipulated by varying the physical background against which the faces appeared. In Experiment I, 80 student subjects observed 18 faces before attempting to recognize them in a sequence of 36 alternatives. For half the subjects, the backgrounds changed from study to test, while for the remainder they stayed the same. In addition, for half the subjects, both the pose and expression of the face also changed, while for the others it remained constant. Changes in pose plus expression and context significantly reduced recognition accuracy for the target faces. Experiment II used an identical design, except that the faces of celebrities replaced the novel faces. The influence of context was eliminated but the effects of pose and expression were maintained. However, when only faces which were actually identified by subjects were considered, the effects of pose and expression, too, were eliminated. The significance of these findings for theories of contextual memory are discussed.