Sample diversity and premise typicality in inductive reasoning: evidence for developmental change

Evaluating whether a limited sample of evidence provides a good basis for induction is a critical cognitive task. We hypothesized that whereas adults evaluate the inductive strength of samples containing multiple pieces of evidence by attending to the relations among the exemplars (e.g., sample diversity), six-year-olds would attend to the degree to which each individual exemplar in a sample independently appears informative (e.g., premise typicality). To test these hypotheses, participants were asked to select between diverse and non-diverse samples to help them learn about basic-level animal categories. Across various between-subject conditions (N=133), we varied the typicality present in the diverse and non-diverse samples. We found that adults reliably selected to examine diverse over non-diverse samples, regardless of exemplar typicality, six-year-olds preferred to examine samples containing typical exemplars, regardless of sample diversity, and nine-year-olds were somewhat in the midst of this developmental transition.     

Triangulating Political Responsibility: The Motivated Formation of Responsibility Judgments

This article analyzes the process through which partisan bias arises during the formation of citizens' judgments of political responsibility. Informed by theories of motivated political reasoning, it argues that exposure to partisan cues motivates partisans to pursue directional goals, goals which bias the cognitive processing of information and, in turn, overall judgments of responsibility. It further argues that the nature of this biased processing will be such that partisans devalue information inconsistent with their partisan affect. Using a pair of experiments, I test these hypotheses by manipulating both objective evidence concerning gubernatorial responsibility for a state's fiscal imbalance and the presence of partisan cues. Findings support both sets of expectations. The results also suggest that the effects of partisan bias are greater in judgments tied to institutional actions than in those tied to institutional roles and expectations.     

We Value What Values Us: The Appeal of Identity-Affirming Science

Members of the public (Study 1; n =  184) and university students (Study 2; n =  101) evaluated a piece of research and indicated their support for its continuation. The research findings were held constant, but the methods that revealed those findings were attributed to either neuroscience or social science, and the conclusions based on those findings were biased either in favor of men or in favor of women. Study 1 revealed that participants were more positive about research that affirmed their gender identity and that was based on neuroscience rather than social science. Study 2 found this pattern to be apparent in more specialist samples. Indeed, participants with some scientific training were more influenced by research that affirmed the reader's gender identity. Participants with less scientific training, in comparison, were more influenced by the type of science described when making judgments about the value of the research. Contrary to popular claims, this suggests that scientific knowledge alone is no protection against the effects of bias on research evaluation. Implications for the practice and popularization of science are discussed.     

Monotonicity and Reasoning with Exceptions

A proposal by Ferguson [2003, Argumentation 17, 335–346] for a fully monotonic argument form allowing for the expression of defeasible generalizations is critically examined and rejected as a general solution. It is argued that (i) his proposal reaches less than the default-logician’s solution allows, e.g., the monotonously derived conclusion is one-sided and itself not defeasible. (ii) when applied to a suitable example, his proposal derives the wrong conclusion. Unsuccessful remedies are discussed.     

The Logic of Critique

This paper attempts to define the concept of critique, explain its function␣and properties and distinguish it from the close concept of evaluation. It is argued that, beyond the argument, a critique is concerned with the position of the proponent relatively to the reality the argument is about. Moreover, a critique is itself an argument in which assumptions regarding the position of the proponent are justified for a given audience on the basis of the proponent’s argumentative background within a specific domain.     

Supporting the formal verification of mathematical texts

The formal verification of mathematical texts is one of the most interesting applications for computer systems. In fact, we argue that the expert language of mathematics is the natural choice for achieving efficient mathematician–machine interaction. Our empirical approach, the analysis of carefully authored textbook proofs, forces us to focus on the language and the reasoning pattern that mathematician use when presenting proofs to colleagues and students. Enabling a machine to understand and follow such language and argumentation is seen to be the key to usable and acceptable math assistant systems. In this paper, we first perform an analysis of three textbook proofs by hand; we then describe a computational framework that aims at mechanising such an analysis. The resulting proof-of-concept implementation is capable of processing simple textbook proofs and constitutes promising steps towards a natural mathematician–machine interface for proof development and verification.     

The development of possibility judgment within and across domains

The ability to differentiate possible events from impossible ones is an invaluable skill when reasoning about claims that transcend the perceptual evidence at hand, yet preschool-aged children do not readily make this differentiation when reasoning about physically extraordinary events [Shtulman, A., &; Carey, S. (2007). Improbable or impossible? How children reason about the possibility of extraordinary claims. Child Development, 78, 1015–1032]. The present study sought to determine whether this failure stems from deficits in domain-specific knowledge or deficits in the domain-general procedure by which possibility judgments are made. Participants (48 children aged 4-9 years olds and 16 adults) were asked to judge the possibility of three types of extraordinary events – physical, psychological, and biological – and to justify their judgments of impossibility. Developmental changes in the ability to differentiate improbable events from impossible events were qualitatively similar across domains. Moreover, participants’ propensity to judge improbable events possible was significantly correlated with the quality of their justifications, both within and across domains. These findings suggest that modal development involves a domain-general change in how modal claims are evaluated.     

Evaluating Dialectical Structures

This paper develops concepts and procedures for the evaluation of complex debates. They provide means for answering such questions as whether a thesis has to be considered as proven or disproven in a debate or who carries a burden of proof. While being based on classical logic, this framework represents an (argument-based) approach to non-monotonic, or defeasible reasoning. Debates are analysed as dialectical structures, i.e. argumentation systems with an attack- as well as a support-relationship. The recursive status assignment over the arguments is conditionalised on proponents in a debate. The problem of multiple status assignments arising on circular structures is solved by showing that uniqueness can be guaranteed qua reconstruction of a debate. The notion of burden of proof as well as other discursive aims rational proponents pursue in a debate is defined within the framework.     

The Hypothetical Syllogism

The hypothetical syllogism is invalid in standard interpretations of conditional sentences. Many arguments of this sort are quite compelling, though, and you can wonder what makes them so. I shall argue that it is our parsimony in regard to connections among events and states of affairs. All manner of things just might, for all we know, be bound up with one another in all sorts of ways. But ordinarily it is better, being simpler, to assume they are unconnected. In so doing, we jump to the conclusions of some compelling but invalid arguments.