Double threshold orders: a new axiomatization

The paper presents some new results concerning the axiomatization of double threshold preference structures. Such structures, which have been introduced in order to model a situation of hesitation between the strict preference and the indifference, were not axiomatized through the use of a single characteristic relation. We give two theorems for this purpose, exploiting a four valued logic recently introduced by the authors as a preference modeling language under hesitation. © 1998 John Wiley & Sons, Ltd.     

Jensen Effects and African/Coloured/Indian/White differences on Raven's Standard Progressive Matrices in South Africa

A test is made to determine whether various ethnic group differences on tests of cognitive performance in South Africa are like the Black/White differences in the United States in being positively associated with a tests' g loadings, where g is the general factor of intelligence. A non-parametric re-analysis is made of data from 1056 White, 1063 Indian, 778 mixed-race “Coloured,” and 1093 Black 14 year olds on the Raven's Standard Progressive Matrices Test in South Africa, given without time limits by Owen (1992) [Personality and Individual Differences, 13, 149]. The new analyses showed that the more highly correlated an item was with g, the more it predicted the White/Indian/Coloured/African differences on the test (Spearman's rhos from 0.35 to 0.85; all Ps<0.01). The effects remained regardless of which group g was extracted from. Understanding group differences around the world requires new research on the nature and nurture of g.     

Empowering Engineering Students in Ethical Risk Management: An Experimental Study

Science and Engineering Ethics - The complexity of industrial reality, the plurality of legitimate perspectives on risks and the role of emotions in decision-making raise important ethical issues...     

Developmental changes of sleep spindles and their impact on sleep‐dependent memory consolidation and general cognitive abilities: A longitudinal approach

Sleep spindles are related to sleep‐dependent memory consolidation and general cognitive abilities. However, they undergo drastic maturational changes during adolescence. Here we used a longitudinal approach (across 7 years) to explore whether developmental changes in sleep spindle density can explain individual differences in sleep‐dependent memory consolidation and general cognitive abilities. Ambulatory polysomnography was recorded during four nights in 34 healthy subjects (24 female) with two nights (baseline and experimental) at initial recording (age range 8–11 years) and two nights at follow‐up recording (age range 14–18 years). For declarative learning, participants encoded word pairs with a subsequent recall before and after sleep. General cognitive abilities were measured by the Wechsler Intelligence Scale. Higher slow (11–13 Hz) than fast (13–15 Hz) spindle density at frontal, central, and parietal sites during initial recordings, followed by a shift to higher fast than slow spindle density at central and parietal sites during follow‐up recordings, suggest that mature spindle topography develops throughout adolescence. Fast spindle density increases from baseline to experimental night were positively related to sleep‐dependent memory consolidation. In addition, we found that the development of fast spindles predicted the improvement in memory consolidation across the two longitudinal measurements, a finding that underlines a crucial role for mature fast spindles for sleep‐dependent memory consolidation. Furthermore, slow spindle changes across adolescence were related to general cognitive abilities, a relationship that could indicate the maturation of frontal networks relevant for efficient cognitive processing. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=7NXJzm8HbIw and https://www.youtube.com/watch?v=iuMQY1OIJ0s     

ALTERNATIVE AXIOMATICS AND COMPLEXITY OF DELIBERATIVE STIT THEORIES

We propose two alternatives to Xu’s axiomatization of Chellas’s STIT. The first one simplifies its presentation, and also provides an alternative axiomatization of the deliberative STIT. The second one starts from the idea that the historic necessity operator can be defined as an abbreviation of operators of agency, and can thus be eliminated from the logic of Chellas’s STIT. The second axiomatization also allows us to establish that the problem of deciding the satisfiability of a STIT formula without temporal operators is NP-complete in the single-agent case, and is NEXPTIME-complete in the multiagent case, both for the deliberative and Chellas’s STIT.     

The genetics and evolution of the general factor of personality

Three studies tested the hypothesis that a general factor of personality (GFP) underlies diverse individual differences including altruism, the Big Five factors of Openness, Conscientiousness, Extraversion, Agreeableness, and Emotional Stability, and the EAS temperament traits of Emotional Stability, Activity, and Sociability. In Study 1, 214 university students completed 36 personality scales. In Study 2, 322 pairs of monozygotic (MZ) and dizygotic (DZ) twins completed 29 5-point rating scales plus questionnaires. In Study 3, 575 pairs of 2- to 9-year-old Korean twins were rated by their mothers on 25 temperament scales. Factor analyses revealed a hierarchical organization with GFP at the apex and the Big Five and/or EAS temperament scales intermediate. The twin data show GFP has an early age of onset with 50% of the variance attributable to non-additive (dominance) genetic influence and 50% to unique, non-shared environmental influence. We discuss a life history matrix encompassing brain size, maturational speed, and longevity, plus emotional intelligence and the personality disorders, and suggest natural selection acted directionally to endow people with more cooperative and less contentious personalities than their archaic ancestors, or nearest living relatives, the chimpanzees.     

Actual environments do affect motivation and psychological adjustment: A test of self-determination theory in a natural setting

This study examined the impact of the actual environment on changes in psychological adjustment over time. According to Self-Determination Theory (SDT; Deci and Ryan, Intrinsic motivation and self-determination in human behavior, 1985a, Plenum, New York; J Res Pers 19:109–134, 1985b; Psychol Inq 11:227–268, 2000), environments that are objectively supportive of autonomy should facilitate psychological adjustment through their impact on people’s subjective perceptions of autonomy and self-determined motivation. The present study tested this hypothesis using a prospective design with nursing homes residents. Results from structural equation modeling showed that actual autonomy-supportive nursing home environments were positively associated with residents’ perceptions of autonomy that in turn predicted self-determined motivation in major life domains. Self-determined motivation, in turn, predicted increases in psychological adjustment over a one-year period. Theoretical implications of the present findings are discussed in line with SDT.

A General Factor of Personality (GFP) from two meta-analyses of the Big Five: and

In two studies, we used structural equation models to test the hypothesis that a General Factor of Personality (GFP) occupies the apex of the hierarchy of personality. In Study 1, we found a GFP that explained 45% of the reliable variance in a model that went from the Big Five to the Big Two to the Big One in the 14 studies of inter-scale correlations (N = 4496) assembled by Digman (1997). A higher order factor of Alpha/Stability was defined by Conscientiousness, Emotional Stability, and Agreeableness, with loadings of from 0.61 to 0.70, while Beta/Plasticity was defined by Openness and Extraversion with loadings of 0.55 and 0.77. In turn, the GFP was defined by Alpha and Beta with loadings of 0.67. In Study 2, a GFP explained 44% of the reliable variance in a similar model using data from a published meta-analysis of the Big Five (N = 4000) by Mount, Barrick, Scullen, and Rounds (2005). Strong general factors such as these, based on large data sets with good model fits that cross validate perfectly, are unlikely to be due to artifacts and response sets.     

Valuing information and options: an experimental study

Participants in four studies were faced with everyday‐life decision scenarios involving risk, such as purchasing an airline ticket whose price may change. They were asked to state their maximum willingness to pay (WTP) for resolving the uncertainty with either perfect information or an option. The two are strategically equivalent, therefore, should be valued in the same way. Across all experiments, individuals tend to value the option more than the information. In addition, the distributions of responses reveal frequent and gross violations of normative bounds. Contrary to normative predictions, no relationship is found between individuals' valuation of the gamble and their reported WTP for information or option. Furthermore, although participants pay attention to the probabilities of outcomes in valuing the gambles, they ignore the probabilities in valuing uncertainty resolution. Several reasoning heuristics that participants use to come up with a value of information are identified, and it appears that the Information and Option contexts tend to trigger different heuristics. Shift in reference point and regret are consistent with the Information–Option valuation discrepancy. Copyright © 2007 John Wiley & Sons, Ltd.     

Resilience and hypothalamic-pituitary-adrenal axis reactivity under acute stress in young men

The present study examined the relationship between resilience (measured using the Resilience Scale for Adults) and hypothalamic-pituitary-adrenal (HPA) axis reactivity. We examined the subjective and cortisol responses of 28 healthy young men to an acute stressor (public speech task). Eight saliva samples were collected in order to obtain the response curve (anticipation, reactivity, recuperation) for each subject. ANOVA indicated that highly resilient individuals tended to display less mood deterioration than less resilient individuals (marginal p(time x group interaction) = 0.075). They also revealed that the former tended to secrete less cortisol overall than the latter during the experiment (marginal p(main group effect) = 0.087) but this effect was not uniform across time (p(time x group interaction) = 0.029). Additional analyses performed to identify the source of this interaction revealed that resilience moderates cortisol secretion in anticipation of the stressor (i.e. highly resilient individuals secreted less cortisol than less resilient ones, p = 0.05) but that it is not conductive to lower HPA reactivity amidst stress (i.e. there was no difference between groups in the increase in cortisol secretion from baseline to peak). The recovery slopes were likewise not statistically different. The implications of these findings regarding health are discussed.