Recent studies in human and nonhuman primates demonstrate that auditory objects, including speech sounds, are identified in anterior superior temporal cortex projecting directly to inferior frontal regions and not along a posterior pathway, as classically assumed. By contrast, the role of posterior temporal regions in speech and language remains largely unexplained, although a concept of vocal gestures may be helpful.

previous research into human traits has reached impressive consensus regarding at least some traits, but recent evidence suggests these to be genetically heterogeneous. this is problematic for theories of the neurobiology of human traits. future research should more closely integrate genetic, behavioral, and psychometric research to arrive at biologically validated measurement instruments, which may be better used to understand the mediating role of these traits in the association between genetic variants and complex behaviors.

In their account of the origins of human collaborative abilities, Tomasello et al. rely heavily on reasoning and evidence from adult–child collaborations. Peer collaborations are not discussed, but early peer collaborations differ from early adult–child collaborations. Describing and explaining the similarities and differences in shared intentionality with peers and adults will bring us closer to understanding the developmental mechanisms.

To conclude that language evolved from vocalizations, through gestures, then back to vocalizations again, one must first reject the simpler hypothesis that language evolved from prelinguistic vocalizations. There is no reason to do so. Many studies – not cited by Arbib – document continuities in behavior, perception, cognition, and neurophysiology between human speech and primate vocal communication.

Are rules processes or similarity processes the default for acquisition of grammatical knowledge during natural second language acquisition? Whereas Pothos argues similarity processes are the default in the many areas he reviews, including artificial grammar learning and first language development, I suggest, citing evidence, that in second language acquisition of grammatical morphology “rules processes” may be the default.

in this commentary, i argue that the theory presented by sagvolden et al. can be much stronger if its scope is limited, if its developmental aspects are refined, if it can be made to generate testable predictions, and if it can be supported with more data from humans.

with respect to questions of fact, people use heuristics – mental short-cuts, or rules of thumb, that generally work well, but that also lead to systematic errors. people use moral heuristics too – moral short-cuts, or rules of thumb, that lead to mistaken and even absurd moral judgments. these judgments are highly relevant not only to morality, but to law and politics as well. examples are given from a number of domains, including risk regulation, punishment, reproduction and sexuality, and the act/omission distinction. in all of these contexts, rapid, intuitive judgments make a great deal of sense, but sometimes produce moral mistakes that are replicated in law and policy. one implication is that moral assessments ought not to be made by appealing to intuitions about exotic cases and problems; those intuitions are particularly unlikely to be reliable. another implication is that some deeply held moral judgments are unsound if they are products of moral heuristics. the idea of error-prone heuristics is especially controversial in the moral domain, where agreement on the correct answer may be hard to elicit; but in many contexts, heuristics are at work and they do real damage. moral framing effects, including those in the context of obligations to future generations, are also discussed.

Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model – based on self-interest – fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life.

Extrapolation of Steels & Belpaeme’s (S&B) results show that colour is a culturalist category. Populations will only share the category of colour if it is built into the system. If “left to themselves” different populations may or may not stumble on the colour category. Populations that do not share a colour category may still be able to communicate in a wide variety of environments.

Tomasello et al. point up the mutual interdependency of the unique human capacity for intersubjectivity and the evolution and institutionalization of culture. Since both intersubjectivity and cultural cooperation require localized knowledge, Homo sapiens is highly reliant on such knowledge and in that sense is a highly localized species, requiring special means to surmount cultural misreadings and to achieve translocal, or global, interconnection.

Depue & Morrone-Strupinsky (D&M-S) have elaborated a detailed description of the motivational system for affiliation and its neurological basis. This “bottom-up” approach, based almost entirely on studies of nonhuman species, fails to connect with personality differences at the human level. A “top-down” approach looks for common biological markers in human and nonhuman species and relates these to behavior in both.

Canonical utility theory may have adopted its selfishness postulate because it lacked theoretical rationales for two major kinds of incentive: empathic utility and self-signaling. Empathy – using vicarious experiences to occasion your emotions – gives these experiences market value as a means of avoiding the staleness of self-generated emotion. Self-signaling is inevitable in anyone trying to overcome a perceived character flaw. Hyperbolic discounting of future reward supplies incentive mechanisms for both empathic utility and self-signaling. Neither can be effectively suppressed for an experimental game.

The notion that manual gestures played an important role in the evolution of human language was strengthened by the discovery of mirror neurons in monkey area F5, the proposed homologue of human Broca's area. This idea is central to the thesis developed by Arbib, and lending further support to a link between motor resonance mechanisms and language/communication development is the case of autism and congenital blindness. We provide an account of how these conditions may relate to the aforementioned theory.

chicks reared in the absence of light and rat pups reared without extra stimulation fail to exhibit behavioral laterality, implying that a threshold amount of environmental stimulation is necessary for the brain to follow an asymmetry pathway. reverse asymmetry has been reported in the chick, but not the rat, though a sex difference resembling reverse asymmetry has been found in the rat.

The proposal of Steels & Belpaeme (S&B) is on the right track to solve the nativist/empiricist/culturalist controversy. However, their nativist model of colour categorization does not correspond to a proper genetic model. Colour perception is the outcome of a complex process of development. A direct correspondence between genes and colour categories cannot be the right approach to the problem.

In most cases, rule-governed relations and similarity relations can indeed be distinguished by the number of relevant features they require. This criterion is not sufficient, however, to explain other properties of the relations that have a more dichotomous character. I focus on the differential drive for consistency by inferential processes that draw on the two types of relations.

Tomasello et al. highlight how in combination cognitive impairments and affective impairments help explain why individuals with autism do not enter fully into human culture. We query whether the motivational component is a later development in human ontogeny and whether the cognitive level of intention reading is intact in autism. A key question is what neuropsychological impairments underlie this cognitive–affective impairment.

The target article by Henrich et al. describes some economic experiments carried out in fifteen small-scale societies. The results are broadly supportive of an approach to understanding social norms that is commonplace among game theorists. It is therefore perverse that the rhetorical part of the paper should be devoted largely to claiming that “economic man” is an experimental failure that needs to be replaced by an alternative paradigm. This brief commentary contests the paper's caricature of economic theory, and offers a small sample of the enormous volume of experimental data that would need to be overturned before “economic man” could be junked.

Attention-deficit/hyperactivity disorder (ADHD) is currently defined as a cognitive/behavioral developmental disorder where all clinical criteria are behavioral. Inattentiveness, overactivity, and impulsiveness are presently regarded as the main clinical symptoms. The dynamic developmental behavioral theory is based on the hypothesis that altered dopaminergic function plays a pivotal role by failing to modulate nondopaminergic (primarily glutamate and GABA) signal transmission appropriately. A hypofunctioning mesolimbic dopamine branch produces altered reinforcement of behavior and deficient extinction of previously reinforced behavior. This gives rise to delay aversion, development of hyperactivity in novel situations, impulsiveness, deficient sustained attention, increased behavioral variability, and failure to “inhibit” responses (“disinhibition”).

A hypofunctioning mesocortical dopamine branch will cause attention response deficiencies (deficient orienting responses, impaired saccadic eye movements, and poorer attention responses toward a target) and poor behavioral planning (poor executive functions). A hypofunctioning nigrostriatal dopamine branch will cause impaired modulation of motor functions and deficient nondeclarative habit learning and memory. These impairments will give rise to apparent developmental delay, clumsiness, neurological “soft signs,” and a “failure to inhibit” responses when quick reactions are required.

A hypofunctioning mesocortical dopamine branch will cause attention response deficiencies (deficient orienting responses, impaired saccadic eye movements, and poorer attention responses toward a target) and poor behavioral planning (poor executive functions). A hypofunctioning nigrostriatal dopamine branch will cause impaired modulation of motor functions and deficient nondeclarative habit learning and memory. These impairments will give rise to apparent developmental delay, clumsiness, neurological “soft signs,” and a “failure to inhibit” responses when quick reactions are required.

Research into child language reveals that it takes a long time for children to learn the correct mapping of colour words. Steels & Belpaeme’s (S&B’s) guessing game, however, models fast learning of words. We discuss computational studies based on cross-situational learning, which yield results that are more consistent with the empirical child language data than those obtained by S&B.