Replacements for the self-interest axiom may posit weak to strong theories of sociality. Strong sociality may be useful for positing social cognitive mechanisms and their evolution, but weak sociality may work better for identifying interesting group-level outcomes by focusing on deviations from self-interested psychological assumptions. Such theoretical differences are likely to be based on disciplinary expertise, and the challenge for Darwinian integration is to keep the conversation flowing.

Two aspects of Tomasello et al.'s account would benefit from further elaboration: (1) the construction of dialogic cognitive representations through social interaction, and (2) the cognitive consequences of operating with such representations. Vygotskian ideas on internalisation and verbal mediation may help us better to understand how dialogic cognitive representations can transform human cognition.

The simulations of Steels & Belpaeme (S&B) suggest that communication could lead to color categories that are closely shared within a language and potentially diverge across languages. We argue that this is opposite of the patterns that are actually observed in empirical studies of color naming. Focal color choices more often exhibit strong concordance across languages while also showing pronounced variability within any language.

successful application of heuristics depends on how a problem is represented, mentally. moral imagination is a good technique for reflecting on, and sharing, mental representations of ethical dilemmas, including those involving emerging technologies. future research on moral heuristics should use more ecologically valid problems and combine quantitative and qualitative methods.

Research in the neurosciences continues to provide evidence that sleep plays a role in the processes of learning and memory. There is less of a consensus, however, regarding the precise stages of memory development during which sleep is considered a requirement, simply favorable, or not important. This article begins with an overview of recent studies regarding sleep and learning, predominantly in the procedural memory domain, and is measured against our current understanding of the mechanisms that govern memory formation. Based on these considerations, I offer a new neurocognitive framework of procedural learning, consisting first of acquisition, followed by two specific stages of consolidation, one involving a process of stabilization, the other involving enhancement, whereby delayed learning occurs. Psychophysiological evidence indicates that initial acquisition does not rely fundamentally on sleep. This also appears to be true for the stabilization phase of consolidation, with durable representations, resistant to interference, clearly developing in a successful manner during time awake (or just time, per se). In contrast, the consolidation stage, resulting in additional/enhanced learning in the absence of further rehearsal, does appear to rely on the process of sleep, with evidence for specific sleep-stage dependencies across the procedural domain. Evaluations at a molecular, cellular, and systems level currently offer several sleep specific candidates that could play a role in sleep-dependent learning. These include the upregulation of select plasticity-associated genes, increased protein synthesis, changes in neurotransmitter concentration, and specific electrical events in neuronal networks that modulate synaptic potentiation.

In the target article, Sagvolden and collaborators propose that attentional-deficit/hyperactivity disorder (ADHD) is the result of a general behavioral deficit which is mainly caused by a hypofunctioning mesolimbic dopaminergic system. Although we partly agree with this view, we think that it tends to overlook the dysfunction of prefrontal and frontostriatal executive functions by considering them to be a consequence of alterations in reward and extinction mechanisms. Rather, we believe that ADHD is the result of an overall cognitive and behavioral condition, associated to a generalized dopaminergic network dysfunction, and may not be easily attributable to a single basic behavioral function.

the “dynamic developmental” theory of attention-deficit/hyperactivity disorder (adhd) has come full circle from wender's (1971) reinforcement hypothesis. by specifying the principle of time constraints on reinforcement and extinction, the present theory allows for empirical validation. however, the theory implies, but does not discuss, implications for the neurophysiology of comorbidity in adhd. the authors' attribution of comorbid oppositional behavior to parental and societal reinforcement leaves out biological factors.

The data of Henrich et al., when combined with other research, suggest that sharing behavior probably varies systematically across cultures, situations, and individuals. Economic policies founded on recognition of this “radical contingency” would, I argue, nurture economic pluralism rather than attempting to bring the world under one system.

Sound comparative psychology and modern evolutionary and developmental biology (often called evo-devo) emphasize powerful effects of developmental conditions on the expression of genetic endowment. Both demand that evolutionary theorists recognize these effects. Instead, Tomasello et al. compares studies of normal human children with studies of chimpanzees reared and maintained in cognitively deprived conditions, while ignoring studies of chimpanzees in cognitively appropriate environments.

Efforts to bridge emotion theory with neurobiology can be facilitated by dynamic systems (DS) modeling. DS principles stipulate higher-order wholes emerging from lower-order constituents through bidirectional causal processes – offering a common language for psychological and neurobiological models. After identifying some limitations of mainstream emotion theory, I apply DS principles to emotion–cognition relations. I then present a psychological model based on this reconceptualization, identifying trigger, self-amplification, and self-stabilization phases of emotion-appraisal states, leading to consolidating traits. The article goes on to describe neural structures and functions involved in appraisal and emotion, as well as DS mechanisms of integration by which they interact. These mechanisms include nested feedback interactions, global effects of neuromodulation, vertical integration, action-monitoring, and synaptic plasticity, and they are modeled in terms of both functional integration and temporal synchronization. I end by elaborating the psychological model of emotion–appraisal states with reference to neural processes.

Based on brain state-dependent behavioral changes, consolidation of sensorimotor memories has been posited to evolve in two different functional stages. Only the second of these stages requires sleep and leads to performance benefits. Recent results, however, suggest that sleep is not always crucial for the expression of delayed behavioral gains but might be critical for enhancing automaticity in the absence of attention, another expression of memory consolidation.

Future economic game research should include: (1) within-culture comparisons between individuals exposed and not exposed to market integration; (2) use of a game (such as the “Sharing Game”) that enables subjects to maximize their earnings while also maximizing those of the other participant; and (3) assessment of performance in a repeated-trials format that might encourage sensitivity to the games' economic contingencies.

Lewis's dynamic systems approach is a refreshing change from the reflexology of most neuroscience, but it could go a step further: It could include the expected rewardingness of an emotion in the recursive feedback loop that determines whether the emotion will occur. Two possible objections to such a model are discussed: that emotions are not deliberate, and that negative emotions should lose out as instrumental choices.

Four issues that build on the ideas offered by Tomasello et al. are discussed: the developmental course of shared intentionality and its relation to other developing abilities and experiences, and the conceptualization of three key features of the process: motivation, plans and the development of planning, and culture.

steels & belpaeme (s&b) ask how autonomous agents can derive perceptually grounded categories for successful communication, using color categorization as an example. their comparison of nativism, empiricism, and culturalism, although interesting, does not include key biological and technological constraints for seeing color or learning color categories in realistic environments. other neural models have successfully included these constraints.

correcting the relationship between tonic and burst firing modes in dopamine neurons may help normalise stimulus-reinforcement gradients and contingent behaviour in attention-deficit/hyperactivity disorder (adhd) children. but appropriate evaluations of stimuli for developing adaptive plans and controlling impulsivity will not occur without moderating the gain-like functions of serotonin. the “dynamic theory” correctly highlights the need to account for variability in adhd. the dysmaturation of pre-executive information processing is proposed as an explanation.

at the core of the article by sagvolden and colleagues there is a set of data that throws light on an aspect of the adhd phenomenon. but one asks if the authors are a measure too brave to generalise so broadly from the unusually steep reinforcement gradients reported for the human condition and an animal model to the syndrome as a whole.

attention-deficit/hyperactivity disorder (adhd) represents adaptation to defective neurotransmission – an adaptation seldom with benefit. the resulting behavioural style not only increases vulnerability to adverse experiences, but also creates a context in which encountering adversity is more likely. furthermore, the fact that adhd is a highly heritable condition increases the probability of a child with a compromised neurobiological disposition being raised by caregivers with suboptimal resources.

Both the target article and the precommentary demonstrate that relatively simple biobehavioral processes have the cumulative effect of fostering behavioral outcomes characteristic of attention-deficit/hyperactivity disorder (ADHD). As such, the articles illustrate a central theme of Darwinian thinking – basic processes acting over time can produce complex and diverse outcomes. In this commentary, we indicate that tracing the action of processes over time can be facilitated by quantitative methods such as artificial neural networks.

Tomasello et al.'s two prerequisites, we argue, are not sufficient to explain the emergence of Joint Collaboration. An adequate account must include the human-specific capacity to communicate relevant information (that may have initially evolved to ensure efficient cultural learning). This, together with understanding intentional actions, does provide sufficient preconditions for Joint Collaboration without the need to postulate a primary human motive to share others' psychological states.

Insights into the role of sleep in the molecular mechanisms of memory consolidation may come from studies of activity-dependent synaptic plasticity, such as long-term potentiation (LTP). This commentary posits a specific contribution of sleep to LTP stabilization, in which mRNA transported to dendrites during wakefulness is translated during sleep. Brain-derived neurotrophic factor may drive the translation of newly transported and resident mRNA.