First a little background. While research on cultural differences in cognition is very sexy these days, and is in fact older than cognitive science itself (e.g., the work on memory by Bartlett), for about the last 30 years, cognitive psychology, and the study of concepts and categories in particular, has been dominated by objectivism. In the study of concepts and categories, this view was first articulated by Eleanor Rosch1, who argued that our categories "carve the world at its joints," or more technically, "that correlated features or properties create natural 'chunks' or basic level categories that any well-adapted categorization system must acknowledge or exploit"2. The implication of this idea is that everyone, regardless of their cultural background, will have pretty much the same categories, because they're exposed to pretty much the same correlational structure of features in the world. And to a large extent, empirical research has borne this idea out, especially for natural categories like animals and plants3, but even for some artifacts4.
Research over the last decade or so has begun to challenge the objectivist view of concepts. Central to the objectivist view is the idea of a "basic level," which is the level at which within-category similarity is high while between-category similarity is low. Examples of basic level categories include BIRD, CAR, CHAIR, and FISH. Other levels of categorization might admit some cultural variability, under the objectivist view. This is the level that is supposed to be the most constricted by the world's joints. But in the early 90s, researchers produced evidence that the Basic Level shifts with expertise. When people are experts in a particular domain, they tend to treat subordinate level categories (ROBIN, VW BEETLE, DESK CHAIR, GROUPER; categories in which within-level similarity is higher than at the basic level, but between-category similarity is higher as well) like basic level categories. This means that how we perceive the world's correlational structure depends, to some extent, on our knowledge. Along this line, research on theory-based theories of concepts, which argue that things like knowledge of causal relations, in addition to correlational structure, factor in to how we divide the world into categories.
So, with the recognition that knowledge influences categorization, it's possible to start thinking about cultural differences, since knowledge across cultures will certainly differ to some extent. In order to explore potential differences, then, Doug Medin and his colleagues have studied the differences in categorization among different kinds of experts and novices. For example, when categorizing trees, landscapers tend to sort them differently than park maintenance workers and botanists. The latter two groups' sortings tend to agree with scientific taxonomies, as do the sortings of novices, while tree landscapers appear to be using knowledge related to their use of trees (goal-related knowledge) to classify them5. This implies that different cultural groups that have different sets of goals related to the same objects may classify them differently.
Recent research also suggests that there may be cultural differences in categorization that are not due to goal-related knowledge. Atran et al.6 found that three neighboring tribes in a Guatemalan rainforest with similar agrarian lifestyles, and thus similar goal-related knowledge bases, classified plants and animals similarly, but reasoned about them differently. In other words, while their categories divide the world at about the same joints, their concept representations contain different information. It may be, then, that even when members of different cultures classify things in the same way, they actually have very different representations of those things.
In order to explore this, Medin et al.7 conducted a series of experiments comparing the ways in which two expert populations, American fisherman of European ancestry (majority culture) living in Wisconsin and and Menominee Indian fishermen in Wisconsin, categorize and represent freshwater fish. Both populations have similar goal-related knowledge of fish, and live in the same region, so any differences observed can't be attributed to goal-related knowledge from expertise. In the first experiment, both groups were given the names of 44 different species of local fish, and asked list the properties of each species and then to sort them into "meaningful categories," and to provide reasons for sorting them the way they did. They found that the sortings of the two groups were similar, but different in ways that corresponded with the types of justifications that they gave. For example, the majority culture participants used goal-related categories such as food and garbage fish, that the Menominee participants did not have. The Menominee participants, on the other hand, had categories based on the fish's habitat, whereas the majority culture participants did not. These sorting differences were reflected in the justifications the two groups gave, with both groups giving goal-related justifications, but the Menominee giving ecological (e.g., habitat-related) justifications much more often than the majority group participants.
In order to explore these differences in more depth, in a subsequent experiment, Medin et al. asked participants from the two groups to describe interactions between the different species of fish. They found that both groups had a great deal of knowledge of the interactions between different species of fish, but that the types of interactions they described different significantly. The Menominee participants were much more likely to mention two types of interactions: positive interactions, in which one species helps another, and reciprocal interactions, in which two species benefit each other, than were majority participants. These differences in representations are not likely to be due to expertise, since both groups have similar levels of knowledge of the relationships between species, and they're not likely to be goal related, since they both have similar goals (catching the fish). So the differences must be due to some other aspect of culture. Medin et al. offer the following explanation:
Our speculation is that cultural attitudes and beliefs reinforce certain Âhabits of mindÂ or characteristic ways of thinking about some domain. Specifically, responses of majority culture informants concerning ecological relations may be filtered through a goal-related framework whereas the responses of the Menominee informants appear to be less Âviewer-centered.Â (p. 44)They argue that these differences in focus or orientation will make some types information more or less available to the members of the different groups. Thus, the two groups may have the same knowledge base, but some parts of that knowledge base will be easier to access, depending on culturally-induced focus. This will lead the groups to activate different information from their knowledge base when questions are more general. In order to test this explanation, Medin et al. conducted a third experiment in which they directly elicited participants' knowledge of the relationships between the different species of fish, by asking them to sort them on the basis of habitat. By directly eliciting this kind of information, it should be easily accessible even when participants' cultural focus makes this information less accessible in other contexts (e.g., that of the previous experiment). Consistent with this, they found that both groups were able to reliably sort based on habitat. Thus, it does appear that the two groups have the same information in their knowledge base, but that Menomineeinee participants could access ecological information more easily than the majority group participants.
So, the Medin et al. studies, combined with the studies of different types of experts, and the neighboring tribes in Guatemala, all imply that cultural differences in how we categorize and conceptualize things do exist. These differences are likely due to differences in how we interact with those things (i.e., differences in our goals), as well as to cultural differences in focus or perspective. It's important to note, however, that while the differences in our conceptual representations can be big, and important for how we reason, ultimately, the differences in categorization, or how we divide the world up, are pretty small. As Medin et al. put it, cultural differences "emerge against a backdrop of similarity" (p. 58). This similarity is likely due to the correlational structure of the world that motivates the objectivist view. So, Medin et al. state, "cultural models and biological reality both 'bend' a bit in answering one another's demands, and so determining folk conceptions of freshwater fish" (p. 59).
The picture painted by these studies is the one that I try to give when answering questions about cultural differences in cognition in general. The fact is, regardless of where we live, and in what cultures we are raised, we all have highly similar perceptual experiences, and come into the world with the same perceptual and cognitive mechanisms. Thus, for the most part, the way we think about things will be pretty similar, especially for natural categories. However, differences in knowledge across cultures, related to goals and expertise, as well as differences in perspective (Medin et al.'s "cultural models"), will inevitably create differences in the representations we use in processing that information, how accessible certain information is, and as a result, how we reason about things.
1 E.g., Rosch, E. (1974). Linguistic relativity. In A. Silverstein (Ed.), Human Communication: Theoretical Perspectives. New York: Halsted Press; & Rosch, E. (1976). Basic objects in natural categories. Cognitive Psychology, 8, 382-439.
2 Medin, D.L, Ross, N., Atran, S., Cox, D., Wakaua, H.J., Coley, J.D., Proffitt, J.B. & Blok, S. (in press). The Role of Culture in the Folkbiology of Freshwater Fish. Cognitive Psychology, p. 2.
3E.g., Boster, J.S. & DÂAndrade, R. (1989) Natural and human sources of cross-cultural agreement in ornithological classification. American Anthropologist, 91, 132-142.
4 Malt, B. C. (1995). Category coherence in cross-cultural perspective. Cognitive Psychology, 29, 85-148.
5 Medin, D. L., Lynch, E. B., Coley, J. D., & Atran, S. (1997). Categorization and reasoning among tree experts: Do all roads lead to Rome? Cognitive Psychology, 32, 49-96.
6 Atran, S., Medin, D.L., Ross, N., Lynch, E., Vapnarsky, V., Ucan EkÂ,E., Coley, J., Timura, C. & Baran, M. (2002). Folkecology, Cultural Epidemiology and the Spirit of the Commons: A Garden Experiment in the Maya Lowlands. Current Anthropology, 41, 1-23.
7 Medin, D.L, Ross, N., Atran, S., Cox, D., Wakaua, H.J., Coley, J.D., Proffitt, J.B. & Blok, S. (in press). The Role of Culture in the Folkbiology of Freshwater Fish. Cognitive Psychology.