Sergey V. Blok

Folkbiology of freshwater fish

Cross-cultural comparisons of categorization often confound cultural factors with expertise. This paper reports four experiments on the conceptual behavior of Native American and majority-culture fish experts. The two groups live in the same general area and engage in essentially the same set of fishing-related behaviors. Nonetheless, cultural differences were consistently observed. Majority-culture fish experts tended to sort fish into taxonomic and goal-related categories. They also showed an influence of goals on probes of ecological relations, tending to answer in terms of relations involving adult fish. Native American fish experts, in contrast, were more likely to sort ecologically. They were also more likely to see positive and reciprocal ecological relations, tending to answer in terms of relations involving the full life cycle of fish. Further experiments support the view that the cultural differences do not reflect different knowledge bases but rather differences in the organization and accessibility of knowledge. At a minimum the results suggest that similar activities within a well-structured domain do not necessarily lead to common conceptualizations.

Tracing the identity of objects.

This article considers how people judge the identity of objects (e.g., how people decide that a description of an object at one time, t(0), belongs to the same object as a description of it at another time, t(1)). The authors propose a causal continuer model for these judgments, based on an earlier theory by Nozick (1981). According to this model, the 2 descriptions belong to the same object if (a) the object at t(1) is among those that are causally close enough to be genuine continuers of the original and (b) it is the closest of these close-enough contenders. A quantitative version of the model makes accurate predictions about judgments of which a pair of objects is identical to an original (Experiments 1 and 2). The model makes correct qualitative predictions about identity across radical disassembly (Experiment 1) as well as more ordinary transformations (Experiments 2 and 3).

Categorization and reasoning in relation to culture and expertise

Publisher Summary This chapter discusses the categorization and reasoning in relation to culture and expertise. It focuses on categorization and the use of categories in reasoning, and a central question concerns the generality of results across populations. It focuses on the domain of folkbiology for two reasons: There is a rich literature concerning how humans categorize and reason about plants and animals, and there is significant variability in folkbiological knowledge within and between cultures. If it should turn out that variations in knowledge systems, goals, and activities differentially affect peoples ways of conceptualizing the natural world, then lopsided attention to a single participant pool risks biasing interpretation and generalizations that do not generalize. This chapter presents several studies that explore that knowledge and expertise affect how individuals reason about biological categories. These studies indicate that experts apply more specific reasoning strategies than do novices. The latter seem to use more abstract principles when they reason about biological species. The strategies applied by undergraduate participants seem to be a consequence of the lack of knowledge and hence the lack of access to concrete chains of reasoning.

The semantic side of decision making.

The research reported in this paper follows the perspective that decision making is a meaningful act that conveys information. Furthermore, the potential meanings associated with decision options may affect the decisions themselves. This idea is examined in the contexts of compensation, donation, and exchange. In general, judgments were relation dependent and meaning dependent. Furthermore, the results show nonmonotonicities and limited substitutability in a pattern that challenges straightforward ways of mapping decisions onto a common currency of utility.

Induction as conditional probability judgment

Existing research on category-based induction has primarily focused on reasoning aboutblank properties, or predicates that are designed to elicit little prior knowledge. Here, we address reasoning about nonblank properties. We introduce a model of conditional probability that assumes that the conclusion prior probability is revised to the extent warranted by the evidence in the premise. The degree of revision is a function of the relevance of the premise category to the conclusion and the informativeness of the premise statement. An algebraic formulation with no free parameters accurately predicted conditional probabilities for single- and two-premise conditionals (Experiments 1 and 3), as well as problems involving negative evidence (Experiment 2).

Out of Sorts? Some Remedies for Theories of Object Concepts: A Reply to Rhemtulla and Xu (2007)

Concepts of individual objects (e.g., a favorite chair or pet) include knowledge that allows people to identify these objects, sometimes after long stretches of time. In an earlier article, the authors set out experimental findings and mathematical modeling to support the view that judgments of identity depend on people’s beliefs about the causal connections that unite an object’s earlier and later stages. This article examines M. Rhemtulla and F. Xu’s (2007) critique of the causal theory. The authors argue that M. Rhemtulla and F. Xu’s alternative sortal proposal is not a necessary part of identity judgments, is internally inconsistent, leads to conflicts with current theories of categories, and encounters problems explaining empirical dissociations. Previous evidence also suggests that causal factors dominate spatiotemporal continuity and perceptual similarity in direct tests. The authors conclude that the causal theory provides the only existing account consistent with current evidence.

Digging beneath rules and similarity

Pothos suggests dispensing with the distinction between rules and similarity, without defining what is meant by either term. We agree that there are problems with the distinction between rules and similarity, but believe these will be solved only by exploring the representations and processes underlying cases purported to involve rules and similarity.