Mental representation of logical connectives

Logical connectives, such as “AND”, “OR”, “IF . . . THEN”, and “IF AND ONLY IF” are ubiquitous in both language and cognition; however, reasoning with logical connectives is error-prone. We argue that some of these errors may stem from people's tendency to minimize the number of possibilities compatible with logical connectives and to construct a “minimalist” one-possibility representation. As a result, connectives denoting a single possibility (e.g., conjunctions) are likely to be represented correctly, whereas connectives denoting multiple possibilities (e.g., disjunctions or conditionals) are likely to be erroneously represented as conjunctions. These predictions were tested and confirmed in three experiments using different paradigms. In Experiment 1, participants were presented with a multiple-choice task and asked to select all and only those possibilities that would indicate that compound verbal propositions were true versus false. In Experiment 2, a somewhat similar task was used, except that participants were asked later to perform a cued recall of verbal propositions. Finally, Experiment 3 used an old/new recognition paradigm to examine participants' ability to accurately recognize different logical connectives. The results of the three experiments are discussed in relation to theories of representation of possibilities and theories of reasoning.     

Observing responses in rats: Support for the secondary reinforcement hypothesis

Rats' lever presses on a retractable lever earned brief presentations of discriminative stimuli signalling periods in which responding on an alternative lever was either non-reinforced (extinction) or reinforced on a random ratio schedule. The predictions of two theoretical accounts of this behaviour were tested by studying the effects of omitting either the stimulus signalling the reinforced or that signalling the non-reinforced schedule component. Under these conditions rats' behaviour is determined by the conditioned, affective properties of the stimuli rather than by their purely informational properties.     

Rawlsian Civic Education: Political not Minimal

abstract In Political Liberalism and later work John Rawls has recast his theory of justice as fairness in political terms. In order to illustrate the advantages of a liberal political approach to justice over liberal non‐political ones, Rawls discusses what kind of education might be required for future citizens of pluralistic and democratic societies. He advocates a rather minimal conception of civic education that he claims to derive from political liberalism. One group of authors has sided with Rawls’ political perspective and educational proposal, holding that a political approach and educational requirements that are not too demanding would have the advantage of being acceptable to a wide range of citizens with different religious, moral and philosophical perspectives. A second group of authors have criticized Rawls’ educational recommendations, holding that the production of a just society composed of reasonable citizens requires a more demanding civic education and, hence, that the political approach is not viable. The present paper argues that both groups are only partially right, and that there is a third way to understand civic education in Rawlsian terms, a way that is political but not minimal.