Thomas Kuhn's Misunderstood Relation to Kripke-Putnam Essentialism

Kuhn's ‘taxonomic conception’ of natural kinds enables him to defend and re-specify the notion of incommensurability against the idea that it is reference, not meaning/use, that is overwhelmingly important. Kuhn's ghost still lacks any reason to believe that referentialist essentialism undercuts his central arguments in SSR – and indeed, any reason to believe that such essentialism is even coherent, considered as a doctrine about anything remotely resembling our actual science. The actual relation of Kuhn to Kripke-Putnam essentialism, is as follows: Kuhn decisively undermines it – drawing upon the inadequacies of such essentialism when faced with the failure of attempts to instantiate in history or contemporaneously its ‘thought-experiment’ – and leaves the field open instead for his own more ‘realistic’, deflationary way of thinking about the operation of ‘natural kinds’ in science. This revised version was published online in August 2006 with corrections to the Cover Date.     

Positive and negative intergroup contact: Interaction not asymmetry

This research reports a novel investigation into the comparative effects of positive and negative direct and extended intergroup contact on intergroup orientations. It tested the generality of the positive–negative asymmetry effect among majority (N = 357) and minority (N = 101) group members in Iceland. Little evidence of asymmetry was observed: the beneficial effects of positive contact were mostly as strong as the detrimental effects of negative contact, for both direct and extended contact. However, evidence was found for alternative interaction models in which positive contact buffers the negative effects of negative contact, and negative contact enhances the benefits of positive contact. These interaction effects were found only for direct contact and principally in the majority group, but were also found for the minority group, though more weakly. No interaction was observed for extended contact. It appeared that differential group salience elicited by positive and negative contact could partly contribute to the explanation of the observed effects, at least in the majority sample.     

Perceptual and attentional factors in encoding irrelevant spatial information

Numerous studies found superior performance when the irrelevant location of a stimulus and response location were corresponding than when they were not corresponding (Simon effect), suggesting that stimulus location is processed in an obligatory manner. The present study compared Simon effects from the location of a relevant (i.e., to-be-attended) object to those from the location of an irrelevant (i.e., to-be-ignored) object. In four experiments, participants were presented with a rectangular frame and a square, with the relevant object in green or red color and the irrelevant object in gray or white color. Participants’ task was to respond with a lateral keypress to the color of the relevant object, and we varied spatial correspondence between the location of the relevant or the irrelevant object and the response, respectively. Results consistently showed larger Simon effects from the location of the relevant than from the irrelevant object, even when the irrelevant object was made very salient. These results suggest that location processing is largely confined to relevant (i.e., attended) objects, stressing the role of attention shifts for location encoding.     

Extended cognition and the priority of cognitive systems

This essay begins by addressing the role of the so-called Parity Principle in arguments for extended cognition. It is concluded that the Parity Principle does not, by itself, demarcate cognition and that another mark of the cognitive must be sought. The second section of the paper advances two arguments against the extended view of cognition, one of which – the conservatism-or-simplicity argument – appeals to principles of theory selection, and the other of which – the argument from demarcation – draws on a systems-based theory of cognition. The final section contests the claim, made by Andy Clark, that empirical work done by Wayne Gray and colleagues supports the extended view.     

Predictors of majority members' acculturation preferences: Experimental evidence

A study was conducted to test experimentally whether majority members' perceptions of which acculturation strategies minority members prefer would causally impact on majority members' own acculturation preferences, especially their preference for integration. Participants (N = 113) were exposed to videos in which actors who posed as Pakistani minority members voiced different acculturation preferences (integration, assimilation, separation or control condition). Their views were presented as representative of their ethnic group. The effect of this on white British majority participants' own acculturation preferences was measured. As expected, perceived acculturation preferences significantly impacted on own acculturation preferences. In line with predictions, participants' level of prejudice significantly moderated these effects.     

Book reviews

The Story of Gotama Buddha (Jatakanidana) translated by N. A. Jayawickrama, Oxford, Pali Text Society, 1990, xvi, 141 pp. ISBN 0 860 293 5, £4.95.

Dan Cohn‐Sherbok, Issues in Contemporary Judaism. London, Macmillan Academic & Professional, 1991. ISBN 0 333 535 37.

Raymond L. Weiss, Maimonides’ Ethics— The Encounter of Philosophic and Religious Morality. Chicago, University of Chicago Press, 1991. ISBN 0 226 8915 26.

Peter Harrison, ’Religion’ and the Religions in the English Enlightenment. Cambridge, Cambridge University Press, 1990, 277 pp. ISBN 0 521 38530 X, £35 (U.K.).

Michael Dames, Mythic Ireland. London, Thames and Hudson, 1992, 272 pp. ISBN 0 500 01530 9, £14.95 (hardback).

Stephen and Robin Larsen. A Fire in the Mind: The Life of Joseph Campbell. New York, Doubleday, 1991, 636 pp. ISBN 0 385 26635 9. $30.00 U.S.     

Mechanically driven grain boundary relaxation: a mechanism for cyclic hardening in nanocrystalline Ni

Molecular dynamics simulations are used to show that cyclic mechanical loading can relax the non-equilibrium grain boundary (GB) structures of nanocrystalline metals by dissipating energy and reducing the average atomic energy of the system, leading to higher strengths. The GB processes that dominate deformation in these materials allow low-energy boundary configurations to be found through kinematically irreversible structural changes during cycling, which increases the subsequent resistance to plastic deformation.