Generics are sentences such as "ravens are black" and "tigers are striped", which express generalizations concerning kinds. Quantified statements such as "all tigers are striped" or "most ravens are black" also express generalizations, but unlike generics, they specify how many members of the kind have the property in question. Recently, some…

Evolutionary psychologists often propose that humans carry around "stone-age" brains, along with a toolkit of cognitive adaptations designed originally to solve hunter-gatherer problems. This perspective predicts that optimal cognitive performance might sometimes be induced by ancestrally-based problems, those present in ancestral environments,…

There is evidence for developmental hierarchies in the type of information to which infants attend when reasoning about objects. Investigators have questioned the origin of these hierarchies and how infants come to identify new sources of information when reasoning about objects. The goal of the present experiments was to shed light on this debate…

Five experiments using the visual habitation paradigm with 158 infants demonstrated that these 10-month olds did not use property/kind information to establish representations of 2 numerically distinct objects, a finding that provided support for the object-first hypothesis. (SLD)

Category theory concept of a commutative diagram was used to construct a model of the way in which symbolic processes are applied to problem solving. It was shown that several different levels of thought can be distinguished within the basic model. Two experiments testing the theory are reported. (Author/RD)

Human learning may depend upon domain specialized mechanisms. A plausible example is rapid, early learning about the thoughts and feelings of other people. A major achievement in this domain, at about age four in the typically developing child, is the ability to solve problems in which the child attributes false beliefs to other people and…

Three experiments involving balance scale problems were used to characterize and explain developmental differences in three domains of children's thinking: existing knowledge about the problems, ability to acquire new information about them, and process-level differences underlying developmental changes in the first two areas. (BW)

A new model is proposed for explaining children's performance on Pascual-Leone's test of M-space. The new model is used to generate theoretical performance curves for children at four different age levels and seven different levels of stimulus complexity, and it is a viable alternative. Differences between the models are reviewed. (Author/RD)

Nine experiments were conducted to test the hypothesis that short-term memory and information processing share a common pool of scarce resources. (LMO)

An analysis of the quantitative processes underlying conservation of quantity is presented. Models of three quantitative operators--subitizing, counting, and estimation--are derived from adult performance in quantification tasks, and some features of the operators are described. The emergence of conservation is described in terms of the…

Four studies tested the hypothesis that collection structures are easier than classes in numerical reasoning tasks. With perceptual input constant, the collection labels in contrast to the class labels promoted children's insight into certain numerical principles and facilitated the use of these principles in a variety of numerical tasks.…

This paper examines the mental processes involved in inferring perspective changes resulting from the rotation of a spatial array or from the rotation of the viewer of that array. Under certain conditions, viewer-rotation problems become easy and array-rotation problems become difficult. Apparently, an array is fixed vis-a-vis the spatial context.…

Two experiments tested predictions from a theory in which processing load depends on relational complexity (RC), the number of variables related in a single decision. Tasks from six domains (transitivity, hierarchical classification, class inclusion, cardinality, relative-clause sentence comprehension, and hypothesis testing) were administered to…

Piaget's characterization of formal operational thought and human judgment psychologists' model of bounded rationality are two conflicting models dealing with the nature and limits of mature thought. However, a look at the respective databases demonstrates their complementarity and their contribution to understanding mature cognition. (Author/RD)