We support Pepper and Nettle's (P&N's) hypothesised adaptive responses to deprivation. However, we argue that adaptive responses to stress shift with age. Specifically, present-oriented behaviours are adaptive for young people (e.g., in terms of mating and reproduction) but costly for older people in deprived communities who would benefit from investing in grandchildren. Epigenetic mechanisms may be responsible for age-related tactical shifts.

The purpose of human cognition depends on the problem people try to solve. Defining the purpose is difficult, because people seem capable of representing problems in an infinite number of ways. The way in which the function of cognition develops needs to be central to our theories.

Mele's analysis of self-deception is persuasive but it might also be useful to consider the varieties of self-deception that occur in real-world settings. Instances of self-deception can be classified along three dimensions: implicit versus explicit, motivated versus process-based, and public versus private. All three types of self-deception have implications for the scientific research enterprise.

The probabilistic approach to human reasoning is exemplified by the information gain model for the Wason card selection task. Although the model is elegant and original, several key aspects of the model warrant further discussion, particularly those concerning the scope of the task and the choice process of individuals.

We question the sequence of evolutionary transitions leading to ultrasociality in humans proposed by Gowdy & Krall. Evidence indicates that families are, and likely always have been, the primary productive units in human agricultural economies, suggesting that genetic relatedness is key to understanding when the suppression of individual autonomy to the benefit of subsistence groups, that is, extended families, evolved.

Recent results have shown that the relative activation of muscles is different for isometric contractions and for movements. These results exclude an explanation of muscle activation patterns by a combination ofreciprocal and coactivation commands. These results also indicate that joint stiffness is not uniquely determined and that it may be different for isometric contractions and movements.

Aspects of cognitive immaturity may serve both to adapt children to their immediate environment and to prepare them for future ones. Language may have evolved in children's groups in the context of play. Developmental plasticity provides variability upon which natural selection operates, and such plasticity, that likely played an important role in the evolution of language, characterizes human children today.

Object individuation provides a test case for the claim that infants already have a prelinguistic language-of-thought (LOT). By 12 months, infants represent several sortal-kinds: Object, agent, animate, and perhaps artifact. Infants have also encountered many words for object kinds, animals, people, and artifacts, therefore it remains a viable hypothesis that language learning may play a causal role in the acquisition of sortal-kinds, contra Quilty-Dunn et al.

Belief in evolved belief systems stems from using a population-genetic model of evolution that misconstrues the developmental relationship between genes and behaviour, confuses notions of “adapted” and “adaptive,” and ignores the fundamental role of language in the development of human beliefs. We suggest that theories about the evolution of belief would be better grounded in a developmental model of evolution.

This commentary raises two issues: (1) Language processing is hastened not only by internal pressures but also externally by turn-taking in language use; (2) the theory requires nested levels of processing, but linguistic levels do not fully nest; further, it would seem to require multiple memory buffers, otherwise there's no obvious treatment for discontinuous structures, or for verbatim recall.

Byrne's approach to the semifactual conditional captures the reasoning data. However, we argue that it does not account for the processes or principles by which people arrive at representations of even-if conditionals, upon which their reasoning is said to be based. Drawing upon recent work on the suppositional conditional we present such an account.

The target article overestimates the power of money as a motive/incentive in order to justify trying to provide a biological theory. A great deal of the article is spent trying to force-fit other explanations into this course categorization. Lea & Webley's (L&W's) account seems to ignore systematic, individual differences, as well as the literature on many negative affective associations of money and behavioural economics, which is a cognitive account of money motivation.