Biomedical subjects

Douglas L Medin

Publications and source records attributed to Douglas L Medin.

8 recordsLinked to original sources

PubMed2005

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.

Adult↗

PubMed2005

The cultural mind: environmental decision making and cultural modeling within and across populations.

This article describes cross-cultural research on the relation between how people conceptualize nature and how they act in it. Mental models of nature differ dramatically among populations living in the same area and engaged in similar activities. This has novel implications for environmental decision making and management, including common problems. The research offers a distinct perspective on cultural modeling and a unified approach to studies of culture and cognition. The authors argue that cultural transmission and formation consist primarily not in shared rules or norms but in complex distributions of causally connected representations across minds interacting with the environment. The cultural stability and diversity of these representations often derive from rich, biologically prepared mental mechanisms that limit variation to readily transmissible psychological forms. This framework addresses several methodological issues, such as limitations on conceiving culture to be a well-defined system, bounded entity, independent variable, or an internalized component of minds.

Cognition↗

PubMed2005

Ideal is typical.

A well-established finding in research on concepts and categories is that some members are rated as better or more typical examples than others. It is generally thought that typicality reflects centrality, that is, that typical examples are those that are similar to many other members of the category. This interpretation of typicality is based on studies in which participants had little knowledge about the relevant categories. In the present study, experienced fishermen were asked to give goodness-of-example ratings to familiar freshwater fish. These fishermen were of two cultural groups with somewhat different goals and ideals. Typicality was well predicted by fishes' desirability and poorly predicted by their centrality. Further, the two cultural groups differed in their typicality ratings in ways that corresponded to their different goals and ideals. For knowledgeable reasoners typicality in natural taxonomic categories appears based on ideals rather than on centrality.

Animals↗

PubMed2004

SUSTAIN: a network model of category learning.

SUSTAIN (Supervised and Unsupervised STratified Adaptive Incremental Network) is a model of how humans learn categories from examples. SUSTAIN initially assumes a simple category structure. If simple solutions prove inadequate and SUSTAIN is confronted with a surprising event (e.g., it is told that a bat is a mammal instead of a bird), SUSTAIN recruits an additional cluster to represent the surprising event. Newly recruited clusters are available to explain future events and can themselves evolve into prototypes-attractors-rules. SUSTAIN's discovery of category substructure is affected not only by the structure of the world but by the nature of the learning task and the learner's goals. SUSTAIN successfully extends category learning models to studies of inference learning, unsupervised learning, category construction, and contexts in which identification learning is faster than classification learning.

Humans↗

PubMed2004

The native mind: biological categorization and reasoning in development and across cultures.

This article describes cross-cultural and developmental research on folk biology: that is, the study of how people conceptualize living kinds. The combination of a conceptual module for biology and cross-cultural comparison brings a new perspective to theories of categorization and reasoning. From the standpoint of cognitive psychology, the authors find that results gathered from standard populations in industrialized societies often fail to generalize to humanity at large. For example, similarity-driven typicality and diversity effects either are not found or pattern differently when one moves beyond undergraduates. From the perspective of folk biology, standard populations may yield misleading results because they represent examples of especially impoverished experience with nature. Certain phenomena are robust across populations, consistent with notions of a core module.

Adult↗

PubMed2004

Protected values: no omission bias and no framing effects.

Previous studies have suggested that people holding protected values (PVs) show a bias against harmful acts, as opposed to harmful omissions (omission bias). In the present study, we (1) investigated the relationship between PVs and acts versus omissions in risky choices, using a paradigm in which act and omission biases were presented in a symmetrical manner, and (2) examined whether people holding PVs respond differently to framing manipulations. Participants were given environmental scenarios and were asked to make choices between actions and omissions. Both the framing of the outcomes (positive vs. negative) and the outcome certainty (risky vs. certain) were manipulated. In contrast to previous studies, PVs were linked to preferences for acts, rather than for omissions. PVs were more likely to be associated with moral obligations to act than with moral prohibitions against action. Strikingly, people with strong PVs were immune to framing; participants with few PVs showed robust framing effects.

Adolescent↗

PubMed2003

A relevance theory of induction.

A framework theory, organized around the principle of relevance, is proposed for category-based reasoning. According to the relevance principle, people assume that premises are informative with respect to conclusions. This idea leads to the prediction that people will use causal scenarios and property reinforcement strategies in inductive reasoning. These predictions are contrasted with both existing models and normative logic. Judgments of argument strength were gathered in three different countries, and the results showed the importance of both causal scenarios and property reinforcement in category-based inferences. The relation between the relevance framework and existing models of category-based inductive reasoning is discussed in the light of these findings.

Adolescent↗

PubMed2002

A bird's eye view: biological categorization and reasoning within and across cultures.

Many psychological studies of categorization and reasoning use undergraduates to make claims about human conceptualization. Generalizability of findings to other populations is often assumed but rarely tested. Even when comparative studies are conducted, it may be challenging to interpret differences. As a partial remedy, in the present studies we adopt a 'triangulation strategy' to evaluate the ways expertise and culturally different belief systems can lead to different ways of conceptualizing the biological world. We use three groups (US bird experts, US undergraduates, and ordinary Itza' Maya) and two sets of birds (North American and Central American). Categorization tasks show considerable similarity among the three groups' taxonomic sorts, but also systematic differences. Notably, US expert categorization is more similar to Itza' than to US novice categorization. The differences are magnified on inductive reasoning tasks where only undergraduates show patterns of judgment that are largely consistent with current models of category-based taxonomic inference. The Maya commonly employ causal and ecological reasoning rather than taxonomic reasoning. Experts use a mixture of strategies (including causal and ecological reasoning), only some of which current models explain. US and Itza' informants differed markedly when reasoning about passerines (songbirds), reflecting the somewhat different role that songbirds play in the two cultures. The results call into question the importance of similarity-based notions of typicality and central tendency in natural categorization and reasoning. These findings also show that relative expertise leads to a convergence of thought that transcends cultural boundaries and shared experiences.

Adult↗