A genetic two-factor model of the covariation among a subset of Multidimensional Aptitude Battery and Wechsler Adult Intelligence Scale—Revised subtests

The phenotypic and genetic factor structure of performance on five Multidimensional Aptitude Battery (MAB) subtests and one Wechsler Adult Intelligence Scale—Revised (WAIS-R) subtest was explored in 390 adolescent twin pairs (184 monozygotic [MZ]; 206 dizygotic (DZ)). The temporal stability of these measures was derived from a subsample of 49 twin pairs, with test–retest correlations ranging from .67 to .85. A phenotypic factor model, in which performance and verbal factors were correlated, provided a good fit to the data. Genetic modeling was based on the phenotypic factor structure, but also took into account the additive genetic (A), common environmental (C), and unique environmental (E) parameters derived from a fully saturated ACE model. The best fitting model was characterized by a genetic correlated two-factor structure with specific effects, a general common environmental factor, and overlapping unique environmental effects. Results are compared to multivariate genetic models reported in children and adults, with the most notable difference being the growing importance of common genes influencing diverse abilities in adolescence.     

Map-based navigation in mobile robots:: II. A review of map-learning and path-planning strategies

This article reviews map-learning and path-planning strategies within the context of map-based navigation in mobile robots. Concerning map-learning, it distinguishes metric maps from topological maps and describes procedures that help maintain the coherency of these maps. Concerning path-planning, it distinguishes continuous from discretized spaces and describes procedures applicable when the execution of a plan fails. It insists on the need for an integrated conception of such procedures, which must be tightly tailored to the specific robot that is used, notably to the capacities and limitations of its sensory-motor equipment, and to the specific environment that is experienced. A hierarchy of navigation strategies is outlined in the discussion, together with the sort of adaptive capacities each affords to cope with unexpected obstacles or dangers encountered on an animat or robot’s way to its goal.     

Accountability and cooperation in social dilemmas: The influence of others’ reputational concerns

The present study examined the assumption that non-anonymous choices in social dilemmas (i.e., choices for which one is accountable) may influence cooperation, but only to the extent that decision-makers believe that the others will evaluate non-cooperation negatively. Based on a recent review by Kerr (1999), it was expected that under conditions of accountability, decision-makers would cooperate more when they believed that the others within the group were also concerned about their social reputation and therefore were aware of the social norm of cooperation within social dilemmas. As a consequence, it could be expected that non-cooperation by oneself would be evaluated negatively by those others since they seemed to be aware of what ought to be done in a social dilemma (i.e., the norm of cooperation). Results confirmed these predictions and, in addition, also showed that greater willingness to cooperate was associated with stronger feelings of collective concern. The findings are discussed in terms of recent literature on anonymity effects in social dilemmas. This research was part of the second author's master thesis at Maastricht University. The first author was supported by a fellowship of the Netherlands Organization for Scientific Research (NWO, no. 016.005.019).     

Implicit psychophysiology: Effects of common beliefs and idiosyncratic physiological responses symptom reporting

Every individual exhibits unique perceptual, behavioral, and physiological responses within and across a variety of settings. Despite the idiosyncratic nature of responses, we seek to establish theories that generalize across a large number of individuals. A strict idiographic method intensively examines the response patterns of a small number of individuals, whereas a nomothetic approach focuses on common responses across a large number of individuals. In the present investigation, we seek to learn how individuals perceive and report physical symptoms and sensations. We offer a methodology that capitalizes on the unique physiological responses of individuals but, at the same time, assumes that the underlying perceptual processes relevant to symptom reporting are comparable across individuals. Our approach, then, is both idiographic and nomothetic. As will be discussed, this integrative approach has the potential to be applied to a multitude of behaviors and processes that are of interest to social and personality psychologists.     

The adjective generation technique: Consistency of self-description in psychiatric patients

There has been considerable controversy about whether human behavior is consistent across situations and time. Using the adjective generation technique (AGT), Allen and Potkay (1973, 1977a) found that subjects' self-favorability was quite variable and concluded that this did not support Bem and Allen's (1974) position that the consistency would be greater if idiographic assessment techniques were utilized. Bem (1977) criticized this conclusion, making the points that the AGT is not idiographic and that the favorability value of each day should be considered as a single item in a larger test rather than be considered independently. The present study was designed to address both the consistency of behavior across time and also the controversy regarding the AGT. Eleven psychiatric inpatients completed the AGT for 30 consecutive days. The results indicated that while AGT values are highly variable on a day-to-day basis, these values are quite consistent when averaged across even short periods of time. These results are very similar to those reported by Epstein (1979).     

The effects of attentional focus and partner arousal on sexual responding in functional and dysfunctional men

The effects of attentional-focus instructions (self vs partner focus) and level of partner arousal (high, low and ambiguous) on sexual responding, both objectively and subjectively measured, were examined with sexually-functional (N = 8) and sexually-dysfunctional (N = 8) men. These instructional sets were delivered just before the subjects viewed an erotic film depicting a heterosexual couple in which they identified with the male. When both groups were focusing on themselves rather than their partner, higher tumescence was observed when their partner was displaying low arousal. When the partner's level of arousal was ambiguous, highest tumescence was achieved during partner attentional focus. When the partner was displaying high sexual arousal, functional subjects reached highest levels of tumescence during partner focus, while dysfunctional subjects reached highest levels of tumescence during self focus. In fact, high partner arousal seemed to inhibit dysfunctional subjects' tumescence under partner focus. Examination of self-report of arousal data as measured by a subjective lever revealed interesting group differences. Results are discussed in light of possible maintaining factors in sexual dysfunction and their treatment implications.