Errors in the quantification of uncertainty: A product of heuristics or minimal probability knowledge base?

The use of intuitive heuristics (e. g. representativeness and availability) has been put forward as an explanation for peoples' assignment of probabilities (Tversky and Kahneman, 1971). This phenomenon is seen as robust since experts as defined by education (professional psychologisis), despite advanced training in statistics and methodology, rely on the same heuristics as novices (lay people). Both experts and novices, as defined by education, were studied in a series of experiments and further classified as experts and novices according to their probability knowledge base, prior to receiving (or not) a brief (15-minute) training session. Immediately following training, subjects completed a probability test which consisted of ten Tversky and Kahneman (e. g. 1974) problems. The training significantly increased the number of problems correctly solved on the probability test and eliminated the expert/novice education classification. The results of a follow-up test 5 weeks after the experiment indicated that the training group maintained its superior performance. It is proposed that failure to use proper methods of probability assignment may not be due to intrinsic human inference biases or heuristics, but is a result of a minimal probability knowledge base.     

Age and scholarly impact

The claim that older scientists generate research of lower quality than do younger scientists was tested through two analyses in which the age distribution of authors of frequently cited articles in psychology journals was compared with the age distribution of authors of low-impact articles published in the same journals. Most high-impact articles were published by relatively young psychologists, but so were most low-impact articles. When allowance was made for relative numerical representation, there was no evidence that publications from older scientists have less impact. Results are discussed in the context of methodological issues in evaluation of relations between age and scientific achievement.     

Electronic language: A study of word processing by emotionally disturbed children and adolescents in residential treatment

The word-processing language use of a small group of severely emotionally disturbed children and adolescents was compared with their handwritten productions. A content analysis based on a total sample of 4,112 words was performed to explore the thematic and structrual language differences between the two writing modes. The findings indicate that the computer-mediated writing tended to improve some aspects of thematic expression, while the handwritten mode was preferable for certain structural characteristics.     

Automation of learning-set testing: The video-task paradigm

Researchers interested in studying discrimination learning in primates have typically utilized variations in the Wisconsin General Test Apparatus (WGTA). In the present experiment, a new testing apparatus for the study of primate learning is proposed. In the video-task paradigm, rhesus monkeys (Macaca mulatta) respond to computer-generated stimuli by manipulating a joystick. Using this apparatus, discrimination learning-set data for 2 monkeys were obtained. Performance on Trial 2 exceeded 80% within 200 discrimination learning problems. These data illustrate the utility of the video-task paradigm in comparative research. Additionally, the efficient learning and rich data that were characteristic of this study suggest several advantages of the present testing paradigm over traditional WGTA testing.     

Angular homeostasis: IV. Polygonal orbits

Some properties are discussed of regular polygons that may result from angular homeostatic processes in stable orbit. To characterize these homeostatic polygons we need to discuss the winding number, the sidedness (integer, fractional and irrational), multiplicity, envelopes, and density. A regular (i.e., equilateral, equiangular) polygon may be closed in one revolution about its unique center, in multiple revolutions, or not at all. A homeostatic polygon can be generated only if all vertices are included in a single polygon, which occurs if and only if the number of vertices and the number of revolutions required to complete the polygon are relatively prime. For the homeostatic polygon to have a finite number of sides (without repeating itself) the angle subtended by any two successive vertices at the center must be a rational multiple of 2. Biological implications of these properties are illustrated.     

A controlled comparative investigation of psychological treatments for chronic sleep-onset insomnia

A sample of physician-referred chronic insomniacs was randomly allocated to either progressive relaxation, stimulus control, paradoxical intention, placebo or no treatment conditions. Treatment process and outcome were investigated in terms of mean and standard deviation (night to night variability) measures of sleep pattern and sleep quality. Only active treatments were associated with significant improvement, but the nature of treatment gains varied. In particular, stimulus control improved sleep pattern, whereas relaxation affected perception of sleep quality. All improvements were maintained at 17 month follow-up. Results are discussed with reference to previous research and guidelines are given for clinical practice.     

Affective quality of family relations and adolescent identity exploration

The purpose of this study was to examine the relationship between adolescent pubertal status, the affective quality of family relations, and the early adolescent's exploration of a sense of ego identity. Fifty-one intact families with adolescents in the seventh grade agreed to participate. Each family member completed a battery of questionnaires designed to assess familial adaptation to pubertal growth and identity exploration. The results reveal that the affective quality of parent-adolescent relationships and the pubertal status of the adolescent appear to influence the adolescent's exploration of ego identity. The need to establish the functional significance of familial adaptation to adolescent pubertal growth for identity development is discussed.