Covert Categories and Folk Taxonomies (1968)

In 1968, Berlin, Breedlove and Raven studied the botanical ethnography of the Tzeltal Maya people of Chiapas, Mexico. They published an article titled Covert Categories and Folk Taxonomy.^[6]

They found a way to determine, with a high degree of reliability, the major outlines of the named taxonomic structure of the plant world for Tzeltal speakers. Tzeltal is one of the Mayan languages spoken in Mexico, in which most linguists distinguish six different regional dialects. In this study, they found many cultural and meaningful categories related by inclusion that are not conventionally labeled. In their language, the different plants in each category all have a common word structure that puts them apart from all of the other plants. They found that you cannot trace the words back to a single source where all plant names are included. In most languages, they have a "unique beginner" that you can trace the names back to. What Berlin and his colleagues found is that plants and animals are thought of as two separate unnamed classes. In plant taxonomy, the highest level is not a "unique beginner" but is instead represented by four major lexemes or units. These four levels are trees, vines, grasses, and herbs. There are more minor classes that include cacti, agaves, bamboos, etc. There are also very few midlevel plant categories. All of the Tzeltal specific taxa (those that which include no other members) fall into the different major and minor sublevels in their taxonomy. But, it is odd to note that the midlevel category hihte, or "oak", contains the plants sikyok and cikinib which neither share the same linguistic structure with their "parent plant."

To test the hypothesis they first went through the community, observed, and recorded information from their informants comments of the plants in their natural habitats. When they went out into the field to collect data, they noticed that some of 10,000 specimens that were located in the same named contrast set were closely related than others. They take into account the uses of the certain plants including food, herbs, firewood and so on.

A second method that was used helped with searching for possible subgroupings within contrast sets of large numbers was to determine the extent to which informants subdivided lists of plant names. To do this, they wrote the names of different names of plants and animals on slips of papers and then gave them to their informants. After doing this, the informants then put the slips of papers into groups that were most like each other. The results showed that they had no trouble placing them in the different categories of "plants" and "animals." This also showed that though they did not have a word for it they did know of the existence of "plants." After this, they broke down the taxonomy even further by giving them different "plant" names and asking them the same question, as before they had no problem labeling each plant into the different groups or categories.

After they established that they understood the existence of subgroupings, they used three different procedures to find out how they define the features of certain plants. The first procedure was called the triads test in which the informants chose which item out of a group of three was the most different. The results indicated how they group things together based upon similarity.

The second procedure involved constructing folk keys. The keys are used to help distinguish the different plants from the other based upon the traits. They then used these to get a better understanding of why certain plants were put in certain places in their taxonomy. First they would give the informants the names of plants that they had earlier grouped together (when the researchers gave them the slips of papers with names on them), then they were asked to create a key that would help distinguish each plant from each other. In doing this, the informants showed how they make their divisions between plants and decide which group to put them in.

Finally, they conducted a study consisting of paired comparisons of all the items in a particular set of plant names. The informants were asked to compare all the logical pairs in different sets and make logical comparisons and differences amongst them. Characteristics such as stem growth, size and shape of the stem and leaves, and fruit size and shape were all utilized when making the comparisons. This showed Berlin, Breedlove, and Raven what the "definitions" were for a set of terms and they were then able to bring together the like terms that were the most similar according to the informant in question. This study showed what the Tzeltal people deem as the most important features to them when they decide to on certain plants to take care of and plant for their very immediate survival.

This results from this study shows that things that do not have names for the Tzeltal speakers still exist in their eyes. The hierarchies generated by their studies are not arbitrarily spaced, which therefore clearly implies a taxonomic structure. The plants still have a part in their lives and they still identify with them even though they may not have a name. The process of having a given a name to certain life forms in their ecology shows just how much these people are attached to their surroundings. It also shows what to them is considered a life form and what is not. The study proves that we should not take shallow taxonomic hierarchies for granted and should have further studies concerning them to show that the different languages go deeper than we actually let on to them. The study helps outline three great studies that others can use to set up their own studies. It can help researchers understand why sometimes it is hard to identify where the midlevel on a taxonomy hierarchy is or even if it exists at all in a certain community.

General Principles of Classification and Nomenclature in Folk Biology (1973)

One of the first works Berlin published in relation to the budding field of ethnobiology was also one of his more influential: General Principles of Classification and Nomenclature in Folk Biology (1973)^[7] was coauthored with Dennis Breedlove of the California Academy of Sciences and Peter Raven of the Missouri Botanical Garden.

In this journal article, Berlin and team intended to illustrate three hypotheses they felt were properly supported by the data they had acquired during the research they completed. First, it is possible to isolate organisms into linguistically recognized groups called taxa, or classes. Second, these taxa can be further broken down into no more than five smaller classes called taxonomic ethnobiological categories. These smaller categories are defined in terms of certain criteria, such as having certain linguistic or taxonomic feature that are recognizable. They continued to describe how these organisms, flora or fauna, belonging to each of these categories can be arranged into a complex taxonomic hierarchy. The five ethnobiological categories are as follows: unique beginner, life form, generic, specific, and varietal. Most, if not all organisms can be placed taxonomically into these categories. They turned their attentions to the formal linguistic structure of the lexemic nomenclature of the plants and animals and to which taxa each of these organisms belong to. After laying out the criteria and division of the taxa and lexemes, they used the information to discuss the Tzeltal and how they have a nomenclature system incredibly similar to that of Western botany’s division of plants. The data they had obtained studying the Tzeltal and the lexemic system used to name plants was found to conform, with only a few exceptions, to the hypotheses Berlin, Breedlove, and Raven had laid out. Finally, they attempt to show how the principles demonstrated by the research suggest they can be applied to many ethnobiological classification systems since they are general. "While data on some aspects of ethnobotany and ethnozoology, especially the uses of plants and animals, are available from a wide variety of sources, good materials on the classificatory principles underlying folk biological taxonomy and nomenclature in non-Western societies are sadly lacking (1973). Berlin, Breedlove and Raven began to encourage and emphasize the importance in gaining ethnobiological information regarding nomenclature and utilizing the principles they laid out to increase our knowledge of potentially general cognitive categorizing, the people who use these taxonomic systems, and how these systems can influence our view of the environment around us.

In a following article published in the American Ethnologist (1976),^[8] Berlin attempted to address some criticisms he had encountered regarding the ethnobiological concept of category, hereafter also referred to as rank, by applying some of his previous principles to new information on biological classification of the Aguaruna. Some claim the boundaries to determine ranks are arbitrary or that there is no validity to the rank concept. The conclusion of the report stated, "[…] the vast majority of conceptually recognized plant classes in Aguaruna are easily accommodated into one of the proposed ranks in a natural and straightforward fashion. These data suggest that ranks are neither arbitrary nor a mere typological cataloging device invented for the convenience of the ethnographer. On the contrary, the Aguaruna’s view of the plant world provides additional support for the hypothesis that the concept of rank is fundamental to all systems of folk biological classification" (1976).

Ethnobiological Classification (1992)

One of Berlin’s most well known contributions to ethnobiology is his 1992 book, Ethnobiological Classification: Principles of Categorization of Plants and Animals in Traditional Societies.^[9]

In this book, Berlin analyzes the widespread commonalities in classification and naming purposes of the local flora and fauna among traditional, non-literate societies. It helps develop and reaffirm the "universalist" approach to ethnobiology. He explains the "basic principles" that he feels form the groundwork for a comparative ethnobiology. He also talks about the three main levels of classification; generic, specific, and higher-order. He wants to stress the importance of prototypes and the fact that "perceptual motivation" underpins not only genera, but also intermediate and life form categories, although he points out that he understands that the life form categories does not neatly reflect biological taxa. In another part of the book, he explores the patterned variations in ethnobiological knowledge. He brings up an interesting suggestion that ethnobiological nomenclature is not necessarily arbitrary, but often reflects some aspect of the inherent quality of the organism. "Brent Berlin maintains that these patterns can best be explained by the similarity of human beings' largely unconscious appreciation of the natural affinities among groupings of plants and animals: people recognize and name a grouping of organisms quite independently of its actual or potential usefulness or symbolic significance in human society" (2009).^{[citation needed]} This implies that the ability and want to categorize is nearly innate in humans. This claim challenged some anthropologists’ beliefs that one’s sense of reality is determined by culture; that the subjective and unique view one has of their surroundings is controlled little by the world around the individual. He argues throughout the book against his colleagues that only natural species that have "evident utility for man have been named." He constantly argues against a neo-malinowskian functionalism, which makes humans out to seem as simply contemplative materialists unknowingly seeking out only the things that will ensure our happiness and survival and leaving everything else to be on its own for its own survival. He also focused on the structure of ethnobiological classification based on individual nomenclature systems he has researched or seen at work firsthand. He addressed the processes at work to affect the evolution of ethnobiology and the systems involved. Berlin has received a lot of praise on this book. In reference to the book, Terence Hays says, "Here, Berlin deals straightforwardly and systematically with his major critics, acknowledging that ‘the patterns recognized nearly two decades ago must now be restated in light of new evidence and new theoretical insights that have emerged since that time’" (1994:3)^{[citation needed]}.

Medical Ethnobiology of the Highland Maya (1996)

Some of Berlin’s more recent work is focused on medical ethnobiology and modern Mayan populations. In 1996, in collaboration with his wife, Elois Ann Berlin, he published a book entitled Medical Ethnobiology of the Highland Maya of Chiapas, Mexico: The Gastrointestinal Diseases.(1996)^[10]

In this work, Berlin and Berlin focus on two specific Maya speaking groups, the Tzeltal and the Tzotzil. As opposed to focusing on the standard ritual and symbolism approach to understanding the medicinal properties of Mayan healing, the book’s focus is on the ethnobotanical approach. The Tzeltal/Tzotzil have a wealth of knowledge regarding symptomatic diseases and the medicinal herbs that alleviate the symptoms associated with these diseases. Some of the most devastating diseases that affect these people are gastrointestinal diseases. Berlin and Berlin outline the symptomology, treatment, ingredients of the herbs administered, and even the classification of these diseases. Over the time that they researched, they began to realize that the administration of these herbs were condition specific were extremely effective if the condition was known to those treating.

In 2008, Brent Berlin and Elois Ann Berlin were recognized by the Society for Economic Botany. They received the Distinguished Economic Botanist Award. "‘The work of Brent Berlin and Elois Ann Berlin over the last four decades has led to major theoretical advances in cognitive and medical Ethnobiology,’ said Rick Stepp, a member of the council of the Society for Economic Botany."(2008)^[11] Brent Berlin has generated information and new techniques of analyzing data that has influenced many well established members of the field and up and coming students who strive to be an asset to the social sciences.