The target article issues a stirring call for more appropriate treatment of chimpanzees in experimental laboratories. This commentary heartily endorses that position with examples of methods and results found in sign language studies of cross-fostered chimpanzees.

Overall mean performance on intelligence tests by brain-damaged patients with focal lesions can be misleading in regard to localization of intelligence. The widely used WAIS has many subtests that together recruit spatially distant neural “centers,” but individually the subtests reveal localized functions. Moreover, there are kinds of intelligence that defy the localizationist approach inferred from brain damage.

We argue that imaginary worlds gain much of their appeal because they fulfill the fundamental need of human beings to feel connected to other humans. Immersion into story worlds provides a sense of social connection to the characters and groups represented in the world. By fulfilling the need to belong, imaginary worlds provide a buffer against rejection and loneliness.

Climate, diet, lifestyle, and environmental settings have all been shown to modulate mood, play a role in mental disorders, and even pose a mental health risk. Can climatotherapy, in its adaptive approach aiming to restore balance among the economic, social, and ecological realms of human societies, situate itself as a therapeutic avenue for the promotion of sustainable mental health?

Vertes & Eastman argue against the popular idea that dreams promote memory consolidation and suggest instead that REM provides periodic endogenous stimulation during sleep. Although we suspect that much of the debate on the function of dreams reflects a too eager acceptance of the “adaptationist program,” we nonetheless support the position of the authors and propose a specific advantage of periodic REM activity.

[Vertes & Eastman]

The two target articles agree that processes of cultural evolution generate richness and diversity in music, but neither address this question in a focused way. We sketch one way to proceed – and hence suggest how the target articles differ not only in empirical claims, but also in their tacit, prior assumptions about the relationship between cognition and culture.

We challenge the authors' view that Markov blankets are illicitly reified when used to describe organismic boundaries. We do this both on general methodological grounds, where we appeal to a form of structural realism derived from Bayesian cognitive science to dissolve the problem, and by rebutting specific arguments in the target article.

Savage et al. argue for musicality as having evolved for the overarching purpose of social bonding. By way of contrast, we highlight contemporary predictive processing models of human cognitive functioning in which the production and enjoyment of music follows directly from the principle of prediction error minimization.

Burt's argument relies on a motte-and-bailey fallacy. Burt aims to argue against the value of genetics for social science; instead she argues against certain interpretations of a specific kind of genetics tool, polygenic scores (PGSs). The limitations, previously identified by behavioural geneticists including ourselves, do not negate the value of PGSs, let alone genetics in general, for social science.

The “fearful ape hypothesis” could be regarded as one aspect of a more general “suffering ape hypothesis”: Humans are more likely to experience negative emotions (e.g., fear, sadness), aversive symptoms (e.g., pain, fever), and to engage in self-harming behavior (e.g., cutting, suicide attempts) because these might motivate affiliative, consolatory, and supportive behavior from their prosocial environment thereby enhancing evolutionary fitness.

To examine the model of the biological motor control proposed by A. Smith, this commentary briefly introduces some result of stiffness measurements during multi-joint arm movements, and, in the light of these results, discusses how likely it is that stiffness is a control parameter and that the cerebellum solely codes the stiffness, [SMITH]

I would like to stress that early development repeats the evolution of the species. Hence, to understand the origins of functional brain asymmetry and the underlying mechanisms involved in handedness, we have to seek information not only from what we know about human evolution, but also from how an early hand preference develops in our own species.

I raise two issues for Machery's discussion and interpretation of the theory-theory. First, I raise an objection against Machery's claim that theory-theorists take theories to be default bodies of knowledge. Second, I argue that theory-theorists' experimental results do not support Machery's contention that default bodies of knowledge include theories used in their own proprietary kind of categorization process.

Although Burt provides a valuable critique of the scientific value of integrating genetic data into social science research, she reinforces rather than disrupts the age-old horserace between genetic effects and environmental effects. We must move past this false dichotomy to create a new ontology that recognizes the ways in which genetic and environmental processes are inextricably intertwined.

From a statistician's viewpoint, the concepts discussed by Chow relating to “statistical” significance bear little resemblance to the concept developed in statistics. Whether or not “statistical significance” has a place in psychological research is a decision for psychologists, not statisticians, to make, but the decision should be based on a less flawed version of what is being considered.

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,”