Reasoning may be defined as a deliberate effort to coordinate inferences so as to reach justifiable conclusions. Thus defined, reasoning includes collaborative as well as individual forms of cognitive action. The purpose of the present study was to demonstrate a circumstance in which collaborative reasoning is qualitatively superior to individual reasoning. The selection task, a well known logical hypothesis-testing problem, was presented to 143 college undergraduates-32 individuals and 20 groups of 5 or 6 interacting peers. The correct (falsification) response pattern (...) was selected by only 9% of the individuals but by 75% of the groups. The superior performance of the groups was due to collaborative reasoning rather than to imitation or peer pressure. Groups typically co-constructed a structure of arguments qualitatively more sophisticated than that generated by most individuals. The results support Piagetian and Habermasian views of peer interaction as a locus of rational social processes. (shrink)

Yama (2001) has presented an ingenious series of experiments in which he attempts to separate two accounts in the literature of the cause of "matching bias" in conditional reasoning. One account is that the bias arises from the way in which people process negations and the other is that it is due to the larger set sizes associated with negative propositions, rather than negation per se . Yama's experiments show influences of both negation and set size, from which he concludes (...) that both factors contribute to the matching bias that is normally observed. In this note, it is argued that this conclusion is at odds with other findings in the literature, particularly those investigating implicit negation as the cause of the bias. Introducing explicit negations has been shown to remove matching bias completely and not partially, as Yama's account must predict. A possible reconciliation is proposed in terms of subtle contextual differences introduced by Yama's experiments. (shrink)

The phenomenon known as matching bias consists of a tendency to see cases as relevant in logical reasoning tasks when the lexical content of a case matches that of a propositional rule, normally a conditional, which applies to that case. Matching is demonstrated by use of the negations paradigm that is by using conditionals in which the presence and absence of negative components is systematically varied. The phenomenon was first published in 1972 and the present paper reviews the history of (...) research and theorising on the problem in the subsequent 25 years. Theories of matching bias considered include those based on several broad frameworks including the heuristic-analytic theory, the mental models theory, the theory of optimal data selection, and relevance theory as well as the specific processing-negations account. The ability of these theories to account for a range of phenomena is considered, including the effects of linguistic form, realistic content, and explicit negation on the matching bias effect. Of particular importance are recent findings showing that the bias is observable on a wider range of linguistic forms than has generally been thought, and that it is almost entirely dependent on the use of implicit negation in the logical cases to which rules are applied. The reasons for the general suppression of matching when realistic content is used are, however, unclear and a need for further research is identified here. It is concluded that matching bias is a highly robust effect which is closely connected with the problem of understanding implicit negation. Most of the theories in the literature are unable to account for at least some of the major phenomena discovered in research on the bias. The accounts that fare best are those that posit local effects of negation, including the heuristic-analytic and processing negations theories. (shrink)

Individual differences in performance on a variety of selection tasks were examined in three studies employing over 800 participants. Nondeontic tasks were solved disproportionately by individuals of higher cognitive ability. In contrast, responses on two deontic tasks that have shown robust performance facilitationthe Drinking-age Problem and the Sears Problem-were unrelated to cognitive ability. Performance on deontic and nondeontic tasks was consistently associated. Individuals in the correct/correct cell of the bivariate performance matrix were over-represented. That is, individuals giving the modal response (...) on a nondeontic task (P and Q) were significantly less likely to give the modal response on a deontic task (P and not-Q) than were individuals who made the non-modal P and not-Q selection on nondeontic problems. The implications of the results are discussed within the heuristic-analytic framework of Evans (1996; Evans & Over, 1996) and the optimal data selection model of Oaksford and Chater (1994). (shrink)

In order to explain why cultural traits remain stable despite the error-proneness of social learning, Dan Sperber has proposed that human psychology and ecology lead to cultural traits being transformed in the direction of attractors. This means that simple-minded Darwinian models of cultural evolution are not appropriate. Some scientists and philosophers have been concerned that Sperber’s notion of attractors might show more than this, that attractors destroy subtle cultural variation and prevent adaptive cultural evolutionary processes from occurring. I show that (...) Sperber’s view does not have this consequence—that even if there are attractors, cumulative cultural evolution can still occur. (shrink)

This symposium discusses J.-L. Dessalles's account of the evolution of language, which was presented in Why we Talk (OUP 2007).

What is the relationship between logic and reasoning? How do logical norms guide inferential performance? This paper agrees with Gilbert Harman and most of the psychologists that logic is not directly relevant to reasoning. It argues, however, that the mental model theory of logical reasoning allows us to harmonise the basic principles of deductive reasoning and inferential perfomances, and that there is a strong connexion between our inferential norms and actual reasoning, along the lines of Peacocke’s conception of inferential role.

The Frame Problem originated as an obstacle for classical, symbolic A.I. that was adopted, expanded, and reformulated by philosophers. The version of the problem that I focus on, the Holism Problem, points out the difficulty in programming systems to recognize and consider mostly relevant information, given that relevance is context-sensitive. My goal in this thesis is to determine whether the Global Workspace Theory (GWT) can solve the holism problem. GWT proposes that distributed parallel processing, global broadcast, and chaotic itinerancy can (...) solve the problem by providing a system with 1) the speed to search through information, 2) access to the information it needs to compute relevance, 3) the ability to synthesize information. I argue that GWT fails to enable a system to recognize any relevant information because it inadequately responds to the Epistemological Holism Problem, which requires successfully determining the norms by which a system can recognize relevance. (shrink)

This dissertation is devoted to empirically contrasting the Suppositional Theory of conditionals, which holds that indicative conditionals serve the purpose of engaging in hypothetical thought, and Inferentialism, which holds that indicative conditionals express reason relations. Throughout a series of experiments, probabilistic and truth-conditional variants of Inferentialism are investigated using new stimulus materials, which manipulate previously overlooked relevance conditions. These studies are some of the first published studies to directly investigate the central claims of Inferentialism empirically. In contrast, the Suppositional Theory (...) of conditionals has an impressive track record through more than a decade of intensive testing. The evidence for the Suppositional Theory encompasses three sources. Firstly, direct investigations of the probability of indicative conditionals, which substantiate “the Equation” (P(if A, then C) = P(C|A)). Secondly, the pattern of results known as “the defective truth table” effect, which corroborates the de Finetti truth table. And thirdly, indirect evidence from the uncertain and-to-if inference task. Through four studies each of these sources of evidence are scrutinized anew under the application of novel stimulus materials that factorially combine all permutations of prior and relevance levels of two conjoined sentences. The results indicate that the Equation only holds under positive relevance (P(C|A) – P(C|¬A) > 0) for indicative conditionals. In the case of irrelevance (P(C|A) – P(C|¬A) = 0), or negative relevance (P(C|A) – P(C|¬A) < 0), the strong relationship between P(if A, then C) and P(C|A) is disrupted. This finding suggests that participants tend to view natural language conditionals as defective under irrelevance and negative relevance (Chapter 2). Furthermore, most of the participants turn out only to be probabilistically coherent above chance levels for the uncertain and-to-if inference in the positive relevance condition, when applying the Equation (Chapter 3). Finally, the results on the truth table task indicate that the de Finetti truth table is at most descriptive for about a third of the participants (Chapter 4). Conversely, strong evidence for a probabilistic implementation of Inferentialism could be obtained from assessments of P(if A, then C) across relevance levels (Chapter 2) and the participants’ performance on the uncertain-and-to-if inference task (Chapter 3). Yet the results from the truth table task suggest that these findings could not be extended to truth-conditional Inferentialism (Chapter 4). On the contrary, strong dissociations could be found between the presence of an effect of the reason relation reading on the probability and acceptability evaluations of indicative conditionals (and connate sentences), and the lack of an effect of the reason relation reading on the truth evaluation of the same sentences. A bird’s eye view on these surprising results is taken in the final chapter and it is discussed which perspectives these results open up for future research. (shrink)

Explicatures are not cancellable. Theoretical considerations.

Evolutionary psychology—in its ambitious version well formulated by Cosmides and Tooby (e.g., Cosmides & Tooby 1987, Tooby & Cosmides 1992) —will succeed to the extent that it causes cognitive psychologists to rethink central aspects of human cognition in an evolutionary perspective, to the extent, that is, that psychology in general becomes evolutionary. The human species is exceptional by its massive investment in cognition, and in forms of cognitive activity—language, metarepresentation, abstract thinking—that are as unique to humans as echolocation is unique (...) to bats. The promise of evolutionary psychology is thus to help explain not just traits of human psychology that are homologous to those of many other species, but also traits of human psychology that are genuinely exceptional and that in turn help explain the exceptional character of human culture and ecology. However, most of the work done in evolutionary psychology so far is on aspects of human psychology that are not specifically human except in their details. Showing, for instance, how human preferences in mate choice are fine -tuned in the way the theory of evolution would predict is of great interest (see e.g., Buss 1994) but it can be done on the basis of a relatively shallow psychology. This makes work on distinctly human adaptations involving higher cognition of particular importance for defenders of a psychologically ambitious evolutionary psychology. What is often presented (e.g., Pinker, 1997) as the signal achievement of cognitive evolutionary psychology in this respect is the experimental testing of Cosmides’ (1989) hypothesis that there exists an evolved competence to deal with social contracts, and, in particular to detect cheaters. We want to argue that, because of faulty methodological choices—the quasi-exclusive reliance on the four-cards selection task—, the hypothesis has in fact not yet been tested. The plan of this chapter is as follows: We begin, with a short presentation of Cosmides’s social contract hypothesis, of Wason selection task, and of Cosmides’s reasons to use the task in order to test the theory.. (shrink)

This thesis aims to develop a psychologically plausible account of concepts by integrating key insights from philosophy (on the metaphysical basis for concept possession) and psychology (on the mechanisms underlying concept acquisition). I adopt an approach known as informational atomism, developed by Jerry Fodor. Informational atomism is the conjunction of two theses: (i) informational semantics, according to which conceptual content is constituted exhaustively by nomological mind–world relations; and (ii) conceptual atomism, according to which (lexical) concepts have no internal structure. I (...) argue that informational semantics needs to be supplemented by allowing content-constitutive rules of inference (“meaning postulates”). This is because the content of one important class of concepts, the logical terms, is not plausibly informational. And since, it is argued, no principled distinction can be drawn between logical concepts and the rest, the problem that this raises is a general one. An immediate difficulty is that Quine’s classic arguments against the analytic/synthetic distinction suggest that there can be no principled basis for distinguishing content-constitutive rules from the rest. I show that this concern can be overcome by taking a psychological approach: there is a fact of the matter as to whether or not a particular inference is governed by a mentally-represented inference rule, albeit one that analytic philosophy does not have the resources to determine. I then consider the implications of this approach for concept acquisition. One mechanism underlying concept acquisition is the development of perceptual detectors for the objects that we encounter. I investigate how this might work, by drawing on recent ideas in ethology on ‘learning instincts’, and recent insights into the neurological basis for perceptual learning. What emerges is a view of concept acquisition as involving a complex interplay between innate constraints and environmental input. This supports Fodor’s recent move away from radical concept nativism: concept acquisition requires innate mechanisms, but does not require that concepts themselves be innate. (shrink)

As it seems impossible to find reliable evidence to back up hypotheses on the origin of our use of the linguistic tool in our acts of communication, I believe that we may start by pointing as accurately as possible to the processes involved, using a methodology that attempts to reach the levels of adequacy proposed by Chomsky, complemented by those suggested by David Marr. If we conclude that human communication and human language may have had different origins, we might find (...) a new perspective which opens a vast field of research. (shrink)

What is the relation of logic to thinking? My dissertation offers a new argument for the claim that logic is constitutive of thinking in the following sense: representational activity counts as thinking only if it manifests sensitivity to logical rules. In short, thinking has to be minimally logical. An account of thinking has to allow for our freedom to question or revise our commitments – even seemingly obvious conceptual connections – without loss of understanding. This freedom, I argue, requires that (...) thinkers have general abilities to respond to support and tension among their thoughts. And these abilities are constituted by following logical rules. So thinkers have to follow logical rules. But there isn’t just one correct logic for thinking. I show that my view is consistent with logical pluralism: there are a range of correct logics, any one of which a thinker might follow. A logic for thinking does, however, have to contain certain minimal principles: Modus Ponens and Non-Contradiction, and perhaps others. We follow logical rules by exercising logical capacities, which display a distinctive first-person/third-person asymmetry: a subject can find the instances of a rule compelling without seeing them as instances of a rule. As a result, there are two limits on illogical thinking. First, thinkers have to tend to find instances of logical rules compelling. Second, thinkers can’t think in obviously illogical ways. So thinking has to be logical – but not perfectly so. When we try to think, but fail, we produce nonsense. But our failures to think are often subjectively indistinguishable from thinking. To explain how this occurs, I offer an account of nonsense. To be under the illusion that some nonsense makes sense is to enter a pretence that the nonsense is meaningful. Our use of nonsense within the pretence relies on the role of logical form in understanding. Finally, while the normativity of logic doesn’t fall directly out of logical constitutivism, it’s possible to build an attractive account of logical normativity which has logical constitutivism as an integral part. I argue that thinking is necessary for human flourishing, and that this is the source of logical normativity. (shrink)

One of the tasks of language learning is the discovery of the intricate division of labour between the lexical-semantic content of an expression and the pragmatic inferences the expression can be used to convey. Here we investigate experimentally the development of the semantics– pragmatics interface, focusing on Greek-speaking five-year-olds’ interpretation of aspectual expressions such as arxizo (‘ start ’) and degree modifiers such as miso (‘ half ’) and mexri ti mesi (‘ halfway ’). Such expressions are known to give (...) rise to scalar inferences crosslinguistically : for instance, start, even though compatible with expressions denoting completion (e.g. finish), is typically taken to implicate non-completion. Overall, our experiments reveal that children have limited success in deriving scalar implicatures from the use of aspectual verbs but they succeed with ‘ discrete ’ degree modifiers such as ‘ half ’. Furthermore, children are better at spontaneously computing scalar implicatures than judging the pragmatic appropriateness of scalar statements. Finally, children can suspend scalar implicatures in environments where they are not supported. We discuss implications of these results for the scope and limitations of children’s ability to both acquire the lexical semantics of aspectuals and to compute implicatures as part of what the speaker means. (shrink)

Thesis (Ph.D.) - La Trobe University, 2012.

People usually fail the Wason selection task, choosing P and Q cases, when attempting to validate descriptive rules having the form “If P, then Q.” Yet they solve it, selecting P and not-Q cases, when validating deontic rules of the form “If P, then must Q.” The field of evolutionary psychology has overwhelmingly interpreted deontic versions of the selection task in terms of a naturally-selected, domain-specific social-contract or cheating algorithm. This work has done much to promote evolutionary psychology as an (...) alternative to a mindblind sociobiology that ignores the computational structure of cognitive mechanisms in producing people's behaviors. Nevertheless, evolution-minded researchers outside cognitive psychology know little of the ample literature challenging this interpretation and uncritically cite the “cheater-detection module” as a key insight into human cognition. Although a priori arguments for a specially evolved cheater-detection module are plausible, the selection task provides no direct evidence for such a module. (shrink)

Over the past few decades, reasoning and rationality have been the focus of enormous interdisciplinary attention, attracting interest from philosophers, psychologists, economists, statisticians and anthropologists, among others. The widespread interest in the topic reflects the central status of reasoning in human affairs. But it also suggests that there are many different though related projects and tasks which need to be addressed if we are to attain a comprehensive understanding of reasoning.

We present empirical evidence from social psychological research which suggests that standard methods employed when teaching the heuristics and biases program in the context of critical thinking instruction are likelier to facilitate the discernment and correction of biases in others’ reasoning than to have a similar effect in the self-monitoring case. Exemplified by the social phenomenon of false polarization, we suggest that CT instruction may be improved by fostering student’s abilities at counterfactual meta-cognition, and present a corresponding teaching and learning (...) activity. (shrink)

Science is about evaluation, persuasion and logic. In scientific debate, scientists collectively evaluate theories by persuading each other in regard to epistemological qualities such as deduction and fact. There is, however, a flaw intrinsic to evaluation-by-persuasion: an individual can attempt and even succeed in persuading others by asserting that their reasoning is logical when it is not. This is a problem since, from an epistemological perspective, it is not always transparent nor obvious when a persuasive assertion is actually deductively warranted. (...) Empirical research upon reasoning, indeed, supports the notion that assertions are often strongly persuasive for reasons other than their logic. The unreliability of the link between persuasion and logic raises an important methodological issue: how do scientists debate in a manner such that claimed but false “logical” arguments are ignored, and only warranted arguments get to determine theory preference? This need for soundness in debate is a particularly important epistemological concern in cases where the deductive qualities of persuasive argument are not overt, and so cannot be directly checked --such as when they are founded upon Bayesianism probabilistic coherence. The argument presented here is that scientists make the qualities of probabilistic and nonprobabilistic inference sound through how they organize their debate. Scientists, I argue, abide by “epistemological quality control practices” that limit the persuasive power of unsound arguments upon theory evaluation. Examples of such debate quality control practices are publicness, clarity, openness to criticism, and the collective promotion of attempts at theory conjecture and refutation. Methodologically, these quality control practices are extralogical since they do not directly provide scientific inferences with additional logical warrantedness. They function instead in science to generate an epistemological evaluative environment in which persuasiveness is due, and only due, to logic. Their methodological role is therefore to make what is warranted de papyri also what is persuasive in evaluation and debate de cognitio. Several limitations exist upon the soundness of Bayesian inferential coherence – surreptitious revision, logical omniscience, uncertain evidence, old evidence, and new hypotheses. Bayesianism, as a result, can only exist if it is pursued in a debate that is regulated by quality control practices over its inferences. In this context, one can reinterpret Popper’s concern with criticism, openness, refutation and conjecture, as deriving not directly from the needs of logic, but, indirectly, from the need of scientists to create epistemological soundness. (shrink)