We extend Tomasello's discussion of children's developing sense of obligation to testimonial learning. First, we review a battery of behaviors in testimonial exchanges that parallel those described by Tomasello. Second, we explore the variable ways in which children hold others accountable, suggestive that children's evaluations of moral and epistemic responsibilities in joint collaborative activities are distinct.

Leibovich et al. suggest that congruency effects in number perception (biases towards smaller, denser, etc., dots) are evidence for the number's dependence on these dimensions. I argue that they fail to differentiate between effects at three distinct levels of number perception – encoding, representations, and decision making – and that differentiating between these allows the number to be independent from, but correlated with, non-numeric dimensions.

The authors rightly point to the theoretical importance of interactions of space and number through the life span, yet propose a theory with several weaknesses. In addition to proclaiming itself unfalsifiable, its stage-like format and emphasis on the role of selective attention are at odds with what is known about the development of spatial-numerical associations in infancy.

The search for a deep, multileveled understanding of human intelligence is perhaps the grand challenge for 21st-century science, with broad implications for technology. The project of building machines that think like humans is central to meeting this challenge and critical to efforts to craft new technologies for human benefit.

Defense of reproductive choice is an important motivation in women's self-protection psychology for which the “staying alive theory” cannot fully account. Evidence indicates that some elements of women's self-protection psychology function to protect reproductive choice rather than survival, or may be equally well explained by either motivation. Integrating perspectives will result in greater explanatory breadth and precision in theory testing.

Branigan & Pickering (B&P) argue successfully that structural priming provides valuable information for developing psychologically plausible syntactic and semantic theories. I discuss how their approach can be used to help determine whether partially grammaticalized constructions that have undergone semantic change also have undergone syntactic reanalysis. I then consider cases in which evidence from priming cannot distinguish between competing syntactic analyses.

We emphasize the importance of a neuroevolutionary perspective in moving beyond the cognition-emotion dichotomy. Cognitive behavior depends on cortical structures firmly rooted in the emotional brain from which they have evolved. As such, there cannot be cognition without emotion. Endocrine regulation of amygdala connectivity, a neural “switch” between impulsivity and deliberation, further underscores the phylogenetic impossibility of a cognition-emotion dichotomy.

Are grounded procedures such as cleansing value-neutral main effects? Culture-as-situated-cognition theory suggests otherwise. Societies differ in how frequently they trigger membership and individualizing cultural mindsets and their linked mental-procedures – connecting and separating, respectively. Commonly triggered mindsets (and their linked mental-procedures) feel fluent. Fluency feels good. Cleansing can separate from but also connect to others in the form of membership-based rituals.

Autistic, developmental, and nonhuman primate populations fail tasks that are thought to involve attributing beliefs, but not those thought to reflect the representation of knowledge. Instead of knowledge representations being more basic than belief representations, relational mentalizing may explain these observations: The tasks referred to as reflecting “belief” representation, but not the “knowledge” representation tasks, are social conflict designs. They involve mental conflict monitoring after another's mental state is represented – with effects that need to be accounted for.

In contrast to Clarke and Beck's claim that that the approximate number system (ANS) represents rational numbers, we argue for a more modest alternative: The ANS represents natural numbers, and there are separate, non-numeric processes that can be used to represent ratios across a wide range of domains, including natural numbers.

Grounded procedures of separation are conceptualized as a learned concept. The simultaneous cultural universality of the general idea and immense diversity of its implementations might be better understood through the lens of dual inheritance theories. By drawing on examples from developmental psychology and emotion theorizing, we argue that an innate blueprint might underlie learned implementations of cleansing that vary widely.

Our target article modeled conflict within and between groups as an asymmetric game of strategy and developed a framework to explain the evolved neurobiological, psychological, and sociocultural mechanisms underlying attack and defense. Twenty-seven commentaries add insights from diverse disciplines, such as animal biology, evolutionary game theory, human neuroscience, psychology, anthropology, and political science, that collectively extend and supplement this model in three ways. Here we draw attention to the superordinate structure of attack and defense, and its subordinate means to meet the end of status quo maintenance versus change, and we discuss (1) how variations in conflict structure and power disparities between antagonists can impact strategy selection and behavior during attack and defense; (2) how the positions of attack and defense emerge endogenously and are subject to rhetoric and propaganda; and (3) how psychological and economic interventions can transform attacker-defender conflicts into coordination games that allow mutual gains and dispute resolution.

Heyes does well to argue that some of the apparently innate human capabilities for cultural learning can be considered in terms of more general-purpose mechanisms. In the application of this to language, she overlooks some of its most interesting properties. I review three, and then illustrate how mindreading can come from general-purpose mechanism via language.

Evidence from our research on young children's temporal understanding supports Hoerl & McCormack's view that young children rely on a temporal updating system to change representations over time. We propose that the shift from temporal updating to temporal reasoning is enabled by children's expanding representations of event sequences, along with developments in language, memory, and other cognitive competencies.

Phillips et al. argue that our capacity for representing knowledge is more basic than our capacity for representing belief. But they remain neutral on the further claim that our “belief capacity” depends on our “knowledge capacity.” I consider how this further claim might help to explain some of the generalizations the authors catalog, and explore one way of understanding it.

We agree with Clarke and Beck that the approximate number system represents rational numbers, and we demonstrate our support by highlighting the case of the empty set – the non-symbolic manifestation of zero. It is particularly interesting because of its perceptual and semantic uniqueness, and its exploration reveals fundamental new insights about how numerical information is represented.

Our commentators explore the operation of grounded procedures across all levels of analysis in the behavioral sciences, from mental to social, developmental, and evolutionary/functional. Building on them, we offer two integrative principles for systematic effects of grounded procedures to occur. We discuss theoretical topics at each level of analysis, address methodological recommendations, and highlight further extensions of grounded procedures.

Lane et al. imply hypotheses that are questionable: that emotional arousal is a cause of positive change and reconsolidation research can be applied to therapy to alter memory. Given the history of problematic attempts to incorporate memory distortion or high emotional arousal into therapeutic techniques, both of which heralded premature optimism and hubris, I urge open-minded skepticism.

Why has the labeled line versus across-fiber pattern debate of taste coding not been resolved? Erickson suggests that the basic tastes concept has no rational definition to test. Similarly, however, taste neuron types, which are fundamental to the across-fiber pattern concept, have not been formally defined, leaving this concept with no rational definition to test. Consequently, the two concepts are largely indistinguishable.