Evidence for infants' sensitivity to behavior being goal oriented leaves it open as to whether they see such behavior as being designed to lead to an external goal or whether they see it, in addition, as being directed by an internal representation of the goal. We point out the difficulty of finding possible criteria for how infants or children view this matter.

In narrative contexts, people often find themselves mentally rooting for “bad guys.” These circumstances lead to questions about how Sunstein’s moral heuristics function during narrative experiences. In particular, must people undertake explicit moral analysis for the heuristics to apply?

“A dynamic developmental theory of attention-deficit/hyperactivity disorder (ADHD) predominantly hyperactive/impulsive and combined subtypes” is a major contribution linking comparative psychology with clinical developmental neuropsychopathology. In this commentary, I place some critical remarks concerning the theory’s explanation of sleep problems, inhibition, error monitoring, and motor control.

Tomasello et al. have presented a position that is grounded in a conservative perspective of cultural learning, as well as in a rich interpretation of recent findings in early social cognition. Although I applaud their theoretical framework, I argue that data from studies of human infants are not necessarily consistent with the developmental picture that they describe.

We consider Walker's thorough review in the context of thinking about future research on the relation between sleep and memory. We first address methodological issues including type of memory and sleep-stage dependency. We suggest a broader investigation of potential signaling molecules that may be critical to sleep-related consolidation. A brief review of the importance of the stress hormone cortisol illustrates this point.

The proposed dynamic systems model of emotion generation indeed appears considerably more plausible and descriptively adequate than traditional linear models. It also comes much closer to the complex interactions observed in neurobiological research. The proposals regarding self-organization in emerging appraisal-emotion interactions are thought-provoking and attractive. Yet, at this point they are more in the nature of promises than findings, and are clearly in need of corroborating psychological evidence or demonstrated theoretical desirability.

The relationship between game play and naturalistic cooperation, generosity, or market involvement is ambiguous at best, making it difficult to link game results to preferences and beliefs guiding decision-making in daily life. Discounting reputation-based explanations because the games are anonymous, while arguing that game play is guided by motivational structures or framing effects reflecting daily life, is inconsistent.

derived from a rat model, the theory of sagvolden et al. offers an all-explanatory model of attention-deficit/hyperactivity disorder (adhd) anatomy, behaviour, and cognition as being caused predominantly by a hypo-dopaminergic mesolimbic (affecting the mesocortical and nigrostriatal) system, leading to abnormal reward and extinction processes. this model suffers from oversimplification and reductionism, reflecting the limitations of the use of animal models to explain higher mental disorders.

Dynamic systems theory (DS) provides tools for exploring how simpler elements can interact to produce complex psychological configurations. It may, as Lewis demonstrates, provide means for explicating relationships between two reductionist approaches to overlapping sets of phenomena. The result is a description of psychological phenomena at a level that begins to achieve the richness we would hope to achieve in examining psychological life as it is experienced and explored in psychoanalysis.

some commentaries suggest that the attention-deficit/hyperactivity disorder (adhd) theory of this condition does not explain enough. because the theory includes parameters of the delay gradient that vary across individuals and developmental modulation of behavioral outcomes by different environments, it accommodates a wide range of manifestations of adhd symptoms. thus, the argument could instead be made that the theory allows too many degrees of freedom. for many purposes, behavior is better defined in terms of function (e.g., consequences) than in terms of structure (e.g., muscle movements), so cognition is treated here as a variety of behavior rather than as a different category of phenomena. the commentaries are discussed in the context of these and other distinctions, including those between association and selection, between operant and respondent behavior, and between fundamental processes and those that are derivative. other issues include: prosthetic environments, rapidity of developmental change, the concept of inhibition, the form of the delay gradient, and possible directions for experimental research.

Walker proposes that procedural memory formation involves two specific stages of consolidation: wake-dependent stabilization, followed by sleep-dependent enhancement. If sleep-based enhancement of procedural memory formation is now well supported by evidence obtained at different levels of cognitive and neurophysiological organization, wake-dependent mechanisms for stabilization have not been demonstrated as convincingly, and still require more systematic characterization.

Tomasello et al. argue that the “small difference that made a big difference” in the evolution of the human mind was the disposition to share intentions. Chimpanzees are said to understand certain mental states (like intentions), but not share them. We argue that an alternative model is better supported by the data: the capacity to represent mental states (and other unobservable phenomena) is a human specialization that co-evolved with natural language.

population-level asymmetry may be maintained, not by an “evolutionarily stable strategy” pitting a dominant bias against its nondominant opposite, but rather by a genetically based system pitting a directional bias against the absence of any such bias. stability is then achieved through a heterozygotic advantage, maintaining balanced polymorphism. this model may better capture the fundamental trade-off between lateralization and bilateral symmetry.

Selfishness narrowly defined as choosing dominant outcomes independent of context is widely rejected by experimentalists. Humans live in two worlds of personal and impersonal exchange; both are manifestations of human sociality, but the emphasis on preferences rather than cultural norms of personal exchange across time too much reflects a limited economic modeling, and fails to capitalize on the fresher experimental economics message of culture and diversity.

Henrich et al.'s findings are generally consistent with the findings of other experimental field studies. However, the methodological variations deployed across field sites produced several systematic biases in their results. Hence, although the project is destined to become a watershed study, their results should be interpreted prudently.

lateralisation is traditionally viewed by neuroscientists and comparative psychologists from the perspective of the individual; however, for many animals lateralisation evolved in the context of group living. here i discuss the implications of individual lateralisation within the context of the group from an evolutionary ecology perspective, with particular reference to coordinated anti-predator behaviour.

Intention, shared or unshared, is based on the presumption of unknowable and unnecessary motives and mental states in ourselves and others.

this commentary speaks to the relationship between depue & marrone-strupinsky's (d&m-s's) concept of trait affiliation and affiliative memory and the formation of human community, especially among peer groups. the target article suggests a model for how and why dynamic communities form in a number of disparate contexts and under a number of circumstances.

Lewis proposes a “reconceptualization” of how to link the psychology and neurobiology of emotion and cognitive-emotional interactions. His main proposed themes have actually been actively and quantitatively developed in the neural modeling literature for more than 30 years. This commentary summarizes some of these themes and points to areas of particularly active research in this area.

Matthew Walker's article has prompted us to consider neuropsychiatric disorders and pharmacological effects associated with sleep alterations, and aspects of memory affected. Not all disorders involving insomnia show memory impairment, and hypersomnias can be associated with memory deficits. The use of cholinergic medication in dementia indicates that consideration of the link between sleep and memory is more than academic.