The emphasis on innate talent as the basis for outstanding achievement underestimates the importance of hard work. Learned industriousness helps supply the sustained effort required for superior achievement. The goal of having a productive, well-educated citizenry can be furthered by rewarding students for high effort and attending carefully to their individual educational needs.

In the context of the motor skill literature on observational learning and hierarchical skill structuring, Byrne & Russon's findings call into question their standpoint that great apes imitate the behaviour of role models at the programme level. The authors impose a hierarchical model on their observations without properly considering alternative explanations. One such possibility, which stems from a constraints perspective that they dismiss, is put forward.

We applaud Millikan's psychologically plausible version of the causal theory of reference. Her proposal offers a significant clarification of the much-debated relation between concepts and beliefs, and suggests positive directions for future empirical studies of conceptual development. However, Millikan's revision of the causal theory may leave us with no generally satisfying account of concept individuation in the mind.

We outline a view of imitative behaviour as largely internally driven and discuss, based on experimental research, the distinction between program versus action level imitation, the role of organismic constraints, observational learning as vicarious exploration, and imitation as selection in speeded response paradigms.

Halford et al. seek to provide a framework that unifies distinct developmental phenomena. However, in pursuit of this goal, they sidestep crucial aspects of some well-known developmental benchmarks (most notably Transitive Inference and Object Concept), and they do not acknowledge “repeated” or “direct” experience as possibly being more fundamental than relational complexity, instead, ascribe all experience a secondary role.

The evidence for a panhuman, cognitively rooted, essence-based concept of basic natural kind and for certain prototypical phenomenal forms is increasingly compelling, but there remain doubts as to whether these two elements combine with a principle of taxonomy to form a unified, domain-specific theory in the way Atran claims. The appropriateness of the notion of meme can also be questioned, as can the assertion that humans are always grouped in ethnobiological classifications in unambiguous contrast to other animals.

To make genuine progress toward explicating the relation between innate talent and high levels of ability, we need to consider the differences in structure between most everyday abilities and expert performance. Only in expert performance is it possible to show consistently that individuals can acquire skills to circumvent and modify basic characteristics (talent).

Using an articulatory model we show that locus equations make special use of the phonetic space of possible locus patterns. There is nothing articulatorily inevitable about their linearity or slope- intercept characteristics. Nonetheless, articulatory factors do play an important role in the origin of simulated locus equations, but they cannot, by themselves, provide complete explanations for the observed facts. As in other domains, there is interaction between perceptual and motor factors.

The core issue of our target article concerns how relational complexity should be assessed. We propose that assessments must be based on actual cognitive processes used in performing each step of a task. Complexity comparisons are important for the orderly interpretation of research findings. The links between relational complexity theory and several other formulations, as well as its implications for neural functioning, connectionist models, the roles of knowledge, and individual and developmental differences, are considered.

Atran's thesis has strong implications for the doctrine of externalism in concepts (Fodor 1994). Beliefs about biological kinds may involve a degree of deference to scientific categories, but these categories are not truly scientific. They involve instead a folk view of science itself.

The existence of natural talent becomes easier to see at extremes in performance. Practice alone could not account for the differences in performance that exist at the highest levels. Practice and other factors are no doubt important contributors to outstanding performance, but not enough to explain great creative works. Talent is essential.

A number of clarifications of the target article and some corrections are made. I clarify which concepts the thesis was intended to be about, what “descriptionism” means, the difference between “concepts” and “conceptions,” and why extensions are not determined by conceptions. I clarify the meaning of “substances,” how one knows what inductions to project over them, the connection with “basic level categories,” how it is determined what substance a given substance concept is of, how equivocation in concepts occurs, and the role of language in the conception of substances. Finally, I clarify exactly why I said that concepts of individuals, real kinds, and stuffs have “a common structure,”

The locus equation proposal ignores a fundamental difference between human speech perception and nonhuman echolocation and sound localization, offers a questionable account of the function of consonant-vowel coarticulation, and is further undermined if the effects of other forms of coarticulation are considered. The function of coarticulation is to convey phonetic information rapidly and reliably.

Byrne & Russon suggest that the production of action by primates is hierarchically organised. We assess the evidence for hierarchical structure in the comprehension of action by primates. Focusing on work with human children we evaluate several possible indices of program-level comprehension.

Since the BBS article in which Premack and Woodruff (1978) asked “Does the chimpanzee have a theory of mind?,” it has been repeatedly claimed that there is observational and experimental evidence that apes have mental state concepts, such as “want” and “know.” Unlike research on the development of theory of mind in childhood, however, no substantial progress has been made through this work with nonhuman primates. A survey of empirical studies of imitation, self-recognition, social relationships, deception, role-taking, and perspective-taking suggests that in every case where nonhuman primate behavior has been interpreted as a sign of theory of mind, it could instead have occurred by chance or as a product of nonmentalistic processes such as associative learning or inferences based on nonmental categories. Arguments to the effect that, in spite of this, the theory of mind hypothesis should be accepted because it is more parsimonious than alternatives or because it is supported by convergent evidence are not compelling. Such arguments are based on unsupportable assumptions about the role of parsimony in science and either ignore the requirement that convergent evidence proceed from independent assumptions, or fail to show that it supports the theory of mind hypothesis over nonmentalist alternatives. Progress in research on theory of mind requires experimental procedures that can distinguish the theory of mind hypothesis from nonmentalist alternatives. A procedure that may have this potential is proposed. It uses conditional discrimination training and transfer tests to determine whether chimpanzees have the concept “see.” Commentators are invited to identify flaws in the procedure and to suggest alternatives.

Evidence shows that outstanding talent is more than the product of determined effort by people of much the same inborn ability. Indications of inborn individual differences come from very early studies of childhood. No randomly selected child has ever reached world-class achievement by practice alone, which, though essential, cannot itself produce greatness.

Atran's treatment of classification suggests a need to recognize the difference between ontological categories and less metaphysically fundamental distinctions. The shift that scientists have made from classes to individuals may not be as pervasive as he proposes, and the same may be said for the abandonment of essences. It is also possible that the sort of causality that is of concern to scientists plays a role in folk classification.

A systematic relationship between the acoustic structure and phonemic content of speech raises the possibility that processing strategies similar to those described in animals with highly specialized hearing may also operate in the human brain. This idea could be tested by analyzing animal communication calls into locus equations and using those as stimulus tools in neurophysiological studies of auditory neurons.

Byrne & Russon rightly draw attention to complex and neglected aspects of ape imitation. However, program-level imitation as a single, absolute category may mislead us in understanding abstractions involved in imitation. Designing the right experiments will offer clarity. One recent experiment has shown imitation of sequential structure: What is needed to test other components of what the authors propose?

Although the relations between second formant (F2) onset and F2 vowel are extremely regular and contain important information about place of articulation of the voiced stops, they are not sufficient for its identification. Using quadratic discriminant analysis of a new data set, it is shown that F3 onset and F3 vowel can also contribute substantial additional information to help identify the consonants.