Although humans are endowed with domain-specific constraints for acquiring informal biology, its construction requires considerable experience with living things and their cultural representations. Less experienced adults may not know what constitutes generic species, and young children may rely on personification rather than category-based inference. Atran's postulate of the living-kind module that promptly produces universal folk taxonomy does not seem tenable.

Atran adds a synthesis of much of the literature on folk-biological classification to important new experimental data relevant to long-standing inferences about the structure of folk taxonomies. What we know about such systems is somewhat overstated, and key issues remain unresolved, especially concerning the centrality of “generic species,” the primacy of “general purpose” taxonomies, and domain specificity.

Atran argues that an autonomous ethnobiological information-processing module exists. This module imputes a “deep causal essence” to folk-biological taxa and uses a hierarchy of taxonomic ranks. I argue that Atran's own data suggest that rank is not an essential feature of the ethnobiological module, and that ethnobiological causal essences may be generalized to other domains and vice versa, limiting its autonomy.

Atran's putative module for folk biology is evaluated with respect to evidence from patients showing category-specific impairments for living kinds. Existing neuropsychological evidence provides no support for the primacy of categorization at the generic species level. We outline reasons for this and emphasize that such claims should be tested using inductive reasoning tasks.

Work with people with Williams syndrome is reviewed relative to Atran's claim that the universality of taxonomic rank in the animal and plant domains derives from a biological construal of generic species. From this work it is argued that a biological construal of animals is not necessary for the construction of the adult taxonomy of animals and therefore that the existence of an animal (or plant) taxonomy cannot be taken as evidence of a biological domain.

The evidence Atran uses to support innate biological principles could just as well support learning, just as in another realm often cited as a candidate for innate knowledge, “naive psychology.”

Pace Atran, (1) folk physics, (2) folk biology, and (3) folk psychology rest on informationally encapsulated modules that emerge before language: a gifted austic person who can see objects and animals perfectly well can nonetheless be incommunicatively mind blind.

Reasons are given for believing that it is premature to abandon the idea that domain-general models of concept learning can explain how human beings understand the biological world. Questions are raised about whether the evidence for domain specificity is convincing, and it is suggested that two constraints on domain-general concept learning models may be sufficient to account for the available data.

Universal ranks in folk biological taxonomy probably apply to taxonomies of cultural artifacts. We cannot call folk biological cognition domain-specific and modular. Color categorization may manifest unique organization, which would result from known neurology and the nature of color as an attribute. But folk biology does not adduce equivalent evidence. A global process of increasing differentiation similarly affects folk taxonomy, color categorization, and other practices germane to Atran's anthropology of science; this is beclouded by claims of specificity and modularity.

Atran advances three theses: our folk-biological taxonomy is (1) universal, (2) innate, and (3) the product of natural selection. I argue that Atran offers insufficient support for theses (2) and (3) and that his evolutionary psychology thus amounts to nothing more than a just-so story.

Atran proposes that humans have a unique, innate, domain-specific tendency to create taxonomies of biological kinds. We show that: (1) in ontogenesis, children develop a notion Atran claims to be innate; (2) what Atran claims is unique to biological kinds may be found in artifact kinds; and (3) although Atran proposes a domain-specific mental construct for biological rank, it can be explained in domain- general terms.

The concept of rank is not a very clear one. Claims that two concepts occupy the same rank in different domains are in danger of being unintelligible. Examples show how hard it is to understand Atran's claim that the most significant concepts in folk biology occur at a higher level than nonbiological concepts. A reformulation preserves some of what Atran wants to claim.

From a developmental and comparative perspective, folk biology is a core “meme.” The universality and resistance to change in such core “memes” may be a function of the developmental timing of cognitive domains during childhood. Evidence from cognitive development in humans, monkeys, and apes is discussed. Suggestions for a developmental research program are offered.

A reanalysis of Atran's data is presented in which the comparison between Itzaj and Michigan animal names is represented in spatial rather than taxonomic form. Similarity among all subjects is also represented in spatial terms. Finally, culturally shared knowledge between the two cultures is shown to be about ten times larger than the culture-specific component unique to each culture.

Atran reifies Fodor's metaphor of modularity to create a truth-producing apparatus to generate a priori taxonomies or natural kinds that lock a tautology in place.

There are problems with Atran's argument for an innate cognitive module for folk biology. He has been too quick to assume innate origins for what might plausibly be learned. Furthermore, in his characterization he includes aspects – essentialist reasoning and inductions from classes – that are not domain-specific. Finally, his characterization compromises his argument that the module is pretheoretical.

This commentary stresses the importance of Atran's work for the development of a new cognitive anthropology, but questions both his particular use of Dawkins's “meme” model and the general usefulness of the meme model for understanding folk-taxonomies as cultural phenomena.

The empirical advances the target article makes over Atran (1990) tend not so much to enrich our knowledge of the “folk taxonomic” hierarchy as to militate against the idea of one. Folk-biological domain-specific universals are to be found not in “taxonomic” kind-kind subordination relations, but in the relation of individual organisms to low ranking kinds and in the peculiarities of those kinds.

The hierarchical reach of Atran's cognitive universals is unclear, and some of the key concepts used to discuss them are notorious for their imprecision. Although ideas of class hierarchy pervade Atran's discussion, other ways of thinking are also allowed. The history and practice of systematic biology suggests that a nonclass hierarchical and continuity-based way of thinking has been common there until recently.

Atran conjectures that a triggering algorithm for a living- kind module could involve inputs from other modules that detect animacy and intentionality. Here we further speculate about how algorithms for detecting specific intentions could be used to trigger between- or within-species categorization. Such categorization may be adaptively important in Eldredge's energy and information realms.