Getting What You Pay For: Children’s Use of Market Norms to Regulate Exchanges

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152678/1/cdev13088.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152678/2/cdev13088_am.pd

A study of preschoolers' and adults' understandings of the domain of illness.

Psychologists have traditionally been interested in people's understanding of illness because of the practical importance of the subject. A second reason for studying illness is to explore the organization of illness concepts as part of a domain-specific cognitive psychology. This dissertation focuses on questions of how children's concepts of illness and related issues might cohere as a particular domain of cognition. Four studies of 4- and 5-year-olds are reported. Study 1 demonstrates that children do understand a particular invisible mechanism (germs) that figures in cases of illness causation. Study 2 reinforces these findings, but also demonstrates that children recognize a variety of ways illness can be caused. Preschoolers do not identify illness with germs. Study 3 tests a set of hypotheses regarding how children (and adults) might define illness. No simple set of social, psychological, and/or biological features are sufficient to identify all and only those conditions recognized as illness. Neither do there seem to be a unique set of inferences that go along with the ascription of illness. Study 4 tests whether the general concept of illness might, instead, serve to constrain inferences that can be made at a lower level of specificity. Knowing that a novel category is a type of illness allows preschoolers (and adults) to infer that certain features will likely be shared among instances of the category (e.g., cause) while other features may not (e.g., psychological effects). These results suggest that there is no unique causal model for illness phenomena. Instead, the domain of illness may be organized around a set of dimensions, and categories which predict values on those dimensions. This level of organization would characterize a type of domain intermediate between naive theories and simple collections of associations.Ph.D.PsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/103614/1/9332096.pdfDescription of 9332096.pdf : Restricted to UM users only

Temporal dynamics of categorization: forgetting as the basis of abstraction and generalization

Historically, models of categorization have focused on how learners track frequencies and co-occurrence information to abstract relevant category features for generalization. The current study takes a different approach by examining how the temporal dynamics of categorization affect abstraction and generalization. In the learning phase of the experiment, all relevant category features were presented an equal number of times across category exemplars. However, the relevant features were presented on one of two learning schedules: massed or interleaved. At a series of immediate and delayed tests, learners were asked to generalize to novel exemplars that contained massed features, interleaved features, or all novel features. The results of this experiment revealed that, at an immediate test, learners more readily generalized based upon features presented on a massed schedule. Conversely, at a delayed test, learners more readily generalized based upon features presented on an interleaved schedule, until information was no longer readily retrievable from memory. These findings suggest that forgetting and retrieval processes engendered by the temporal dynamics of learning are used as a basis of abstraction, implicating forgetting as a central mechanism of generalization