A preliminary study of Hare's “Research Scale for the Assessment of Psychopathy” in mentally-abnormal offenders

The abbreviated (15-item) version of Hare's Research Scale for the Assessment of Psychopathy (RSAP) was investigated in a sample of male admissions to Broadmoor Special Hospital (N = 50), along with five MMPI measures relevant to psychopathy (Impulsivity, Sociability, Psychopathic Deviate, Anxiety and Sociopathy). Patients were assigned to one of four clinical diagnostic groups: Personality Disorder, Mixed (personality disorder with schizophrenia), Schizophrenia and Affective Disorder. Results indicated that while both psychopathic groups (Mixed and Personality Disorder) showed high scores on almost all RSAP items, the Affective Disorder group showed low scores on almost all items. Results of a discriminant function analysis indicated that Hare's RSAP was superior to the MMPI measures at discriminating between psychopaths and non-psychopaths. Use of the discriminant function to re-allocate patients to criterion groups showed a high hit rate (94%) for psychopathic patients but a hit rate of only 61% for non-psychopathic patients. Half of the schizophrenic patients were mis-allocated to the psychopathic group. The results support the idea of an affective deficit common to psychopaths and schizophrenics, but suggest that psychopaths additionally show a deficit which may be characterized by a lack of goal-directed behaviour.     

Defense of a Libertarian Interpretation of Descartes' Account of Judgment1

Widespread scholarly agreement has it that Descartes' theory of judgment favors a compatibilist interpretation. This essay explains and rebuts the standard arguments made on behalf of compatibilist readings, while explaining and defending a libertarian interpretation. Along with relevant Fourth Meditation doctrines and texts, my analysis encompasses a much discussed 1645 letter discussing his account. Although some scholars view the letter as departing from the account of the Meditations, I argue that the two works present a consistent view – allowing us to take at face value that the letter purports to elaborate Descartes' intended meaning in the associated Fourth Meditation passage.     

Hiring on vocational interests to simultaneously improve validity and organizational diversity

We discuss how using vocational interests in the selection process can help address the diversity-validity dilemma. First, we point out how incorporating vocational interests as predictors in selection could help to reduce adverse impact. We further suggest that by using optimal predictor weights, one could simultaneously improve validity while enhancing organisational diversity. Finally, the predictive validity of vocational interests arises from their ability to capture the congruence between individuals and occupations, which is a cross-level phenomenon. Thus, when gathering validity evidence for vocational interests, multi-occupation samples should be incorporated into validation efforts.     

Language preference in the domestic dog (Canis familiaris)

Animal Cognition - Studies have shown that both cotton-top tamarins as well as rats can discriminate between two languages based on rhythmic cues. This is similar to the capabilities of young...     

Sensory scales of taste intensity

The subjective intensity of taste was scaled by the method of magnitude estimation in which Os assigned numbers to designate the apparent strength ofstimulus concentrations. Substances used were sucrose, dextrose, maltose, fructose, saccharin, Sucaryl, sodium chloride, and quinine sulfate. For aqueous solutions of each substance, taste intensity was found to increase as a power function of concentration by weight. Some approximate exponents were: sucrose, 1.3; sodium chloride, 1.4; quinine sulfate. 1.0. The magnitude scale for sucrose was compared with the category scale obtained by a commonly used rating procedure. The category scale turned out to be highly nonlinear.     

Loudness functions under inhibition

In both vision and hearing, a masking or inhibiting stimulus increases the slope (exponent) of the power function that relates sensation to stimulus. The power transformation applies only to the inhibited part of the function where the signal is fainter than the masking noise. Where the signal equals the noise, the function shows a discontinuous knee. Experiments were undertaken to see whether the loudness of a tone of 1000 Hz in a white noise would follow a model based on a constant signal-to-noise ratio at two locations, at the effective threshold and at the knee where the inhibited function meets the uninhibited function. The data accord with the slopes (exponents) generated by the model. The same model gives a fairly good account of the recruitment functions for ears suffering from cochlear involvement (e.g., Méniere’s disease). Regardless of degree of hearing loss, loudness recruitment reaches normal when the tone (1000 Hz) is about 30 dB above the affected threshold.     

Saturation of red: A prothetic continuum

A battery of procedures was used to scale the saturation of colors produced by mixtures of red and gray papers. By direct magnitude estimation, the apparent saturation was found to grow as the1.7 power of the percentage of red in the mixture. The power law was confirmed by the cross-modality matching of loudness to saturation. The inverse continuum, paleness, was also scaled. Saturation appears to be a prothetic continuum because the category scale is curved and the subjective size of the jnd increases as saturation increases.     

Regression effect in psychophysical judgment

Psychophysical judgment, like all other kinds of judgment, involves a matching or equating of two different domains. When the judgment involves the matching of values on two perceptual continua, the observer tends, on the average, to constrict the range of his adjustments on whichever variable is placed under his control. When the observer adjusts each variable in turn, two different regression lines are produced. This regression effect presumably occurs whenever the results of the matching judgments yield less than a perfect correlation. Illustrative examples are given for the continua, loudness, vibration, brightness, and duration.