Germs and angels: the role of testimony in young children's ontology

In three experiments, children's reliance on other people's testimony as compared to their own, first-hand experience was assessed in the domain of ontology. Children ranging from 4 to 8 years were asked to judge whether five different types of entity exist: real entities (e.g. cats, trees) whose existence is evident to everyone; scientific entities (e.g. germs, oxygen) that are normally invisible but whose existence is generally presupposed in everyday discourse; endorsed beings (e.g. the Tooth Fairy, Santa Claus) whose existence is typically endorsed in discourse with young children; equivocal beings (e.g. monsters, witches) whose existence is not typically endorsed in discourse with young children; and impossible entities (e.g. flying pigs, barking cats) that nobody believes in. Children make a broad dichotomy between entities and beings that they claim to exist (real entities; scientific entities; and endorsed beings) and those whose existence they deny (equivocal beings and impossible entities). They also make a more fine-grained distinction among the invisible entities that they claim to exist. Thus, they assert the existence of scientific entities such as germs with more confidence than that of endorsed beings such as Santa Claus. The findings confirm that children's ontological claims extend beyond their first-hand encounters with instances of a given category. Children readily believe in entities that they cannot see for themselves but have been told about. Their confidence in the existence of those entities appears to vary with the pattern of testimony that they receive.     

Visual and tactile guidance of dexterous manipulation tasks: an fMRI study

Models of motor guidance that dynamically adjust to the availability and quality of sensory information are based on the observation that dexterous tasks are routinely performed using various combinations of visual and tactile inputs. However, a dynamic neural system that acquires and processes relevant visual and tactile information remains relatively uncharacterized in humans. In this study, whole-brain functional magnetic resonance images were acquired during a dexterous manipulation task, compression of the end caps of a slender spring prone to buckling, to investigate the neural systems associated with motor guidance under four visual and tactile guidance conditions: (1) eyes closed (no visual input), smooth end caps, (2) eyes dosed, rough end caps, (3) eyes open and watching hand, smooth end caps, and (4) eyes open and watching hand, rough end caps. Performance of the dexterous task remained constant in all conditions. Variations in the two levels of visual input resulted in modulation of activity in the middle and inferior occipital gyrii and inferior parietal lobule, and variation in the two levels of tactile input during the task resulted in modulation of activity in the precentral (primary motor) gyrus. Although significantly active in all conditions, cingulate gyrus, medial frontal gyrus, postcentral gyrus, and cerebellum activities were not modulated by levels of either visual or somatosensory input, and no interaction effects were observed. Together, these data indicate that a fine-tuned motor task guided by varying visual and tactile information engages a distributed and integrated neural complex consisting of control and executive functions and regions that process dynamic sensory information related to guidance functions.     

Visual behavior and perception of trajectories of moving objects with visual occlusion

Experienced athletes in sports with moving objects have shown greater skill when using visual information to anticipate the direction of a moving object than nonexperienced athletes of those sports. Studies have shown that expert athletes are more effective than novices in occlusion situations in the first stages of the sports sequence. In this study, 12 athletes with different competitive experience in sports with moving objects viewed a sequence of tennis ball launches with and without visual occlusion, launched by a ball-shooting machine toward different areas with respect to the participant's position. The relation among visual behavior, occlusion time, and the precision of the task is reviewed. The spot where the balls bounced was analysed by a digital camera and visual behavior by an Eye Tracking System. Analysis showed that the nonexperienced athletes made significantly more errors and were more variable in visual occlusion conditions. Participants had a stable visual search strategy.     

Associative and causal reasoning accounts of causal induction: Symmetries and asymmetries in predictive and diagnostic inferences

Associative and causal reasoning accounts are probably the two most influential types of accounts of causal reasoning processes. Only causal reasoning accounts predict certain asymmetries between predictive (i.e., reasoning from causes to effects) and diagnostic (i.e., reasoning from effects to causes) inferences regarding cue-interaction phenomena (e.g., the overshadowing effect). In the experiments reported here, we attempted to delimit the conditions under which these asymmetries occur. The results show that unless participants perceived the relevance of causal information to solving the task, predictive and diagnostic inferences were symmetrical. Specifically, Experiments 1A and 1B showed that implicitly stressing the relevance of causal information by having participants review the instructions favored the presence of asymmetries between predictive and diagnostic situations. In addition, Experiment 2 showed that explicitly stressing the relevance of causal information by stating the importance of the causal role of events after the instructions were given also favored the asymmetry.     

"Economic man" in cross-cultural perspective: behavioral experiments in 15 small-scale societies

Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model - based on self-interest - fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life.     

Imagining the End of Life: On the Psychology of Advance Medical Decision Making

Near the end of life, individuals often become too ill to express their wishes about the use of life-sustaining medical treatment. Instructional advance directives (i.e., livings wills) are widely advocated as a solution to this problem based on the assumption that healthy people can predict the types of medical treatment they will want to receive if they become seriously ill. In this paper, we review a large body of research from the psychological and medical literatures that challenges this assumption. This research demonstrates that across a wide variety of decision contexts people show limited ability to predict their affective and behavioral reactions to future situations. We outline several ways that policy and law regarding the use of advance directives could be informed by this research, and suggest a number of issues involved in advance medical decision making that could benefit from additional empirical and conceptual attention.

The Positive and Negative Suicide Ideation (PANSI) inventory: psychometric evaluation with adolescent psychiatric inpatient samples

In this study, we evaluated the factor structure of the Positive and Negative Suicide Ideation (PANSI) Inventory (Osman, Gutierrez, Kopper, Barrios, & Chiros, 1998) using confirmatory factor analysis (CFA). The PANSI assesses the frequency of negative risk and protective factors that are related to suicidal behavior. Participants (n = 195) were adolescent psychiatric inpatients, ages 14 to 17 years, in the CFA. Results of the CFA supported the fit for the 2-factor oblique model as the best fitting model. The internal consistency reliability estimates of the 2 subscales, the PANSI-Negative (alpha = .96) and the PANSI-Positive (alpha = .89) were high. Scores on the PANSI scales differentiated between suicide attempters and controls and those at severe risk for suicide and controls. Correlational analyses provide strong support for the concurrent validity of the scales. The results of the logistic regression analyses provide support for the use of this new inventory as a risk measure of suicide-related behaviors: Scores on the PANSI scales (n = 54) also showed satisfactory evidence for test-retest reliability over a 2-week period.     

Mental models in deductive reasoning

We report research investigating the role of mental models in deduction. The first study deals with conjunctive inferences (from one conjunction and two conditional premises) and disjunctive inferences (from one disjunction and the same two conditionals). The second study examines reasoning from multiple conditionals such as: If e then b; If a then b; If b then c; What follows between a and c? The third study addresses reasoning from different sorts of conditional assertions, including conditionals based on if then, only if, and unless. The paper also presents research on figural effects in syllogistic reasoning, on the effects of structure and believability in reasoning from double conditionals, and on reasoning from factual, counterfactual, and semifactual conditionals. The findings of these studies support the model theory, pose some difficulties for rule theories, and show the influence on reasoning of the linguistic structure and the semantic content of problems.     

Life after Kant: Natural purposes and the autopoietic foundations of biological individuality

This paper proposes a basic revision of the understanding of teleology in biological sciences. Since Kant, it has become customary to view purposiveness in organisms as a bias added by the observer; the recent notion of teleonomy expresses well this as-if character of natural purposes. In recent developments in science, however, notions such as self-organization (or complex systems) and the autopoiesis viewpoint, have displaced emergence and circular self-production as central features of life. Contrary to an often superficial reading, Kant gives a multi-faceted account of the living, and anticipates this modern reading of the organism, even introducing the term self-organization for the first time. Our re-reading of Kant in this light is strengthened by a group of philosophers of biology, with Hans Jonas as the central figure, who put back on center stage an organism-centered view of the living, an autonomous center of concern capable of providing an interior perspective. Thus, what is present in nuce in Kant, finds a convergent development from this current of philosophy of biology and the scientific ideas around autopoeisis, two independent but parallel developments culminating in the 1970s. Instead of viewing meaning or value as artifacts or illusions, both agree on a new understanding of a form of immanent teleology as truly biological features, inevitably intertwined with the self-establishment of an identity which is the living process.