Optimisation and mathematical explanation: doing the Lévy Walk

The indispensability argument seeks to establish the existence of mathematical objects. The success of the indispensability argument turns on finding cases of genuine extra-mathematical explanation (the explanation of physical facts by mathematical facts). In this paper, I identify a new case of extra-mathematical explanation, involving the search patterns of fully-aquatic marine predators. I go on to use this case to predict the prevalence of extra-mathematical explanation in science.     

Constraints on the Acquisition of Social Category Concepts

Determining which dimensions of social classification are culturally significant is a developmental challenge. Some suggest this is accomplished by differentially privileging intrinsic visual cues over nonintrinsic cues (Atran, 1990 Atran , S. (1990). Cognitive foundations of natural history: Towards an anthropology of science . New York , NY : Cambridge University Press. [Google Scholar]; Gil-White, 2001 Gil-White , F. J. ( 2001 ). Are ethnic groups biological ‘species’ to the human brain? Essentialism in our cognition of some social categories . Current Anthropology , 42 , 515 – 554 .[Crossref], [Web of Science ®] , [Google Scholar]), whereas others point to the role of noun labels as more general promoters of kind-based reasoning (Bigler &; Liben, 2007 Bigler , R. S. , &; Liben , L. S. ( 2007 ). Developmental intergroup theory: Explaining and reducing children's social stereotyping and prejudice . Current Directions in Psychological Science , 16 , 162 – 166 .[Crossref], [Web of Science ®] , [Google Scholar]; Gelman, 2003 Gelman , S. A. ( 2003 ). The essential child: Origins of essentialism in everyday thought . New York , NY : Oxford University Press .[Crossref] , [Google Scholar]). A novel groups procedure was employed to examine the independent effects of noun labels and visual cues on social categorization. Experiment 1 demonstrated that in the absence of a visual cue, a noun label supported social categorization among 4-year-olds and 7-year-olds. Experiments 2 and 3 demonstrated that children and adults fail to differentiate between intrinsic and nonintrinsic visual cues to category membership, suggesting that this distinction is not central to the acquisition of social category concepts. Experiments 2 and 3 also showed that in the absence of a shared noun label, visual cues were not sufficient for younger children to form social categories. Experiment 4 ruled out a potential demand characteristic in the previous experiments. Together, these results reveal the primacy of verbal labels over visual cues for social categorization in young children and suggest a developmental change between ages 4 and 7 in the ability to construct new representations of social category concepts.     

The distinction between positive and negative reinforcement: use with care

It is customary in behavior analysis to distinguish between positive and negative reinforcement in terms of whether the reinforcing event involves onset or offset of a stimulus. In a previous article (Baron & Galizio, 2005), we concluded that a distinction of these terms is not only ambiguous but has little if any functional significance. Here, we respond to commentaries by a group of distinguished behavior analysts about the issues we raised. Although several of the commentators argued for preservation of the distinction, we remain unconvinced that its benefits outweigh its weaknesses. Because this distinction is so deeply embedded in the language of behavior analysis, we hardly expect that it will be abandoned. However, we hope that the terms positive and negative reinforcement will be used with circumspection and with full knowledge of the confusion they can engender.     

Victimization and PTSD in a Faroese youth total-population sample

Petersen, T., Elklit, A. & Olesen, J. G. (2010). Victimization and PTSD in a Faroese youth total-population sample. Scandinavian Journal of Psychology, 51, 56–62.
The prevalence of twenty traumatic events and negative life events in relation to posttraumatic stress disorder (PTSD) was studied in a Faroese total-population sample of 687 eighth-grade students with a mean age of 14.2 years. Ninety-four percent of the females and 89% of the males were directly exposed to or had witnessed at least one traumatic event or a negative life event. The odds ratios for PTSD after direct and indirect exposure to specific events are described. The lifetime prevalence of PTSD was 20%, whereas another 14% reached a subclinical level of PTSD. After exposure, females had PTSD more than twice as often as males. Being exposed to multiple traumatic events, living with a single parent, and having experienced a traumatic event or a negative life event within the last year were all associated with PTSD and its subscales.     

Situating Coordination and Cooperation Between Ecological and Social Psychology

The major thrust of this analysis is to demonstrate the value of making ecological psychology more social while recognizing that for this to occur, social psychology must become more ecological in the sense that its key concepts must be treated in an embodied manner. I elaborate these propositions by focusing on establishing differences between coordination and cooperation. I then explore a range of relationships between them from a social psychological perspective. To accomplish this integration, which uses the commitment to reciprocity as a joint organizing principle, I use three complementary models—dynamical systems, effectivities-affordances, and a role-rule model of social commitment. Key aspects of the analysis involve (1) elaborating the meaning of Turvey's (1990) Turvey, M. T. 1990. Coordination. American Psychologist, 45: 938–954. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] proper-relations view of coordination and (2) demonstrating the particular relevance of roles and trust as unifying concepts. From this perspective, coordinations occur between roles, rather than individuals, at the level of team play. Team play, in turn, is shown to depend on trust. And trust, in turn, is related to perceptions of dependability, thereby illustrating a critical intersection of ecological and social psychology.     

How to endure presentism

Presentism and endurantism are natural bedfellows: arguments have been mounted from endurantism to presentism and vice versa. I generalise an argument against the compatibility between presentism and endurantism offered recently by Tallant (forthcoming. “Presentism, Persistence and Trans-temporal Dependence.” Philosophical Studies). I then show how to reformulate endurantism so that it is compatible with presentism. I demonstrate that this reformulated version of endurantism can do the same work with respect to the problem of temporary intrinsics as can standard definitions.     

Freedom,Frailty, and Impurity

The central question in Heidegger's philosophy, early and late, is that concerning the meaning of being. Recently, some have suggested that Heidegger himself interprets being to mean presence (Anwesen, Anwesenheit, Praesenz), citing as evidence lectures dating from the 1920s to the 1960s. I argue, on the contrary, that Heidegger regards the equation between being and presence as the hallmark of metaphysical thinking, and that it only ever appears in his texts as a gloss on the philosophical tradition, not as an expression of his own ontological commitments. In his early work Heidegger seeks to confront and even correct the traditional interpretation of being by challenging its narrow preoccupation with presence and the present. By the 1930s, however, he abandons the idea that there is anything to‐be intrinsically right or wrong about with regard to the meaning of being and turns his attention instead to what he calls ‘appropriation’ (Ereignis) or the truth of being, that is, the essentially ahistorical condition for the possibility of all historically contingent interpretations of being, including the metaphysical interpretation of being as presence.     

Suggestions for an Improved M-Limits Technique

Abstract

Bennett, Edward. Personality Assessment and Diagnosis. New York: Ronald Press, 1961 Reviewed by Theodore H. Blau

Honkavaara, Sylvia, The psychology of expression, Cambridge University Press, 1961; British Journal of Psychology, Monograph XXXII, pp. 96. $4.50 Reviewed by Hal M. Wells

Sherman, M. H. (ed.) A Rorschach Reader. New York: International Universities Press, 1960. $7.50. Reviewed by Melvin A. Gravitz, Ph.D.     

Neuropsychological Functioning in Early Hydrocephalus: Review From a Developmental Perspective

Children with hydrocephalus have deficits in several neuropsychological domains. The most notable are motor, visuoperceptual, and visuomotor function. These deficits are multiply determined and depend on the etiology and severity of the hydrocephalus to a large extent. Corpus callosum abnormalities resulting from stretching of callosal fibers and other cortical white matter tracts are implicated as contributory to these deficits. Enlarged ventricles and associated compression of posterior cortical areas also correlate with cognitive impairment. Distinguishing which cognitive domain negatively impacts on the child’s functioning and which domains influence behavior in isolation or in combination has been the subject of numerous studies. Developmentally, we know little about the emergence of neuropsychological functioning in children with hydrocephalus. Study of the effects of hydrocephalus at different stages of development is useful to clinicians and researchers interested in the impact of diffuse neurophysiological damage on cognition in the developing brain. The medical and neuropsychological literature have begun to inform about these effects. The core deficits in hydrocephalus have yet to be explicated and a focus on investigations that answer these questions is required. This review summarizes the current knowledge about neurocognitive sequelae of hydrocephalus.