We also critique the myopic focus on prejudice reduction, but we do not support the call for a reconceptualization of prejudice. Redefining key psychological constructs is unproductive. Also, we point to interpersonal dynamics in cross-group interaction as a key mechanism in the prejudice reduction/collective action paradox and point to solutions involving intrapersonal/interpersonal processes, as well as broader structural intergroup relations.

The discovery of the altruistic punishment mechanism as a replicable experimental result is a genuine achievement of behavioural economics. The hypothesis that cooperation in hunter-gatherer societies is sustained by altruistic punishment is a scientifically legitimate conjecture, but it must be tested against real-world observations. Guala's doubts about the evidential support for this hypothesis are well founded.

Lindquist et al. provide a compelling summary of the brain bases of the onset of emotion. Their conclusions, however, are constrained by typical fMRI techniques that do not assess a key ingredient in emotional experience – timing. We discuss the importance of timing in theories of emotion as well as the implications of neural temporal dynamics for psychological constructionism.

We agree with Vaesen that there is evidence for cognitive differences between humans and other primates. However, it is too early to draw firm conclusions about the uniqueness of the cognitive mechanisms underlying human tool use. Tests of causal understanding are in their infancy, as is the study of animals more distantly related to humans.

One key insight of Frost's target article is that morphology has priority over phonology in writing and in cognitive processing. I argue that this insight raises challenges for theories that put phonology at the heart of the reading process. Instead, it highlights the potential importance of a morphemically based visual pathway to meaning in this process.

Contrary to Vaesen, we argue that a small number of key traits are sufficient to explain modern human tool use. Here we outline and defend the cultural intelligence (CI) hypothesis. In doing so, we critically re-examine the role of social transmission in explaining human tool use.

A spelling model which has evolved in the parallel universe of spelling research resonates with Frost's reading model. Like reading, spelling cannot be based solely on phonology or orthography, but should accommodate all linguistic facets. The cognitive domain of spelling does not take place at the level of single grapheme or phoneme or syllable, but rather, at the lexical level.

This response clarifies, qualifies, and develops our critique of the limits of intergroup liking as a means of challenging intergroup inequality. It does not dispute that dominant groups may espouse negative attitudes towards subordinate groups. Nor does it dispute that prejudice reduction can be an effective way of tackling resulting forms of intergroup hostility. What it does dispute is the assumption that getting dominant group members and subordinate group members to like each other more is the best way of improving intergroup relations that are characterized by relatively stable, institutionally embedded, relations of inequality. In other words, the main target of our critique is the model of change that underlies prejudice reduction interventions and the mainstream concept of “prejudice” on which they are based.

Lindquist et al.'s meta-analysis focuses on adult humans; the authors' emotion model might be strengthened by considering research on infants and animals, highlighting the importance of the limbic system. Reliance on the James–Lange theory is questionable; emotions typically occur instantaneously, with dubious dependence on bodily feedback for affect. Stronger evidence for localization might be obtained using more precise emotion terms and alterative localization methods.

Contrary to Guala, I claim that several mechanisms can explain punishment in humans. Here I focus on reputation-based cooperation – and I explore how it can lead to punishment under situations that may or may not be perceived as being anonymous. Additionally, no particular mechanism stands out in predicting an excess of punishment under constrained lab conditions.

In our response, we clarify important theoretical differences between basic emotion and psychological construction approaches. We evaluate the empirical status of the basic emotion approach, addressing whether it requires brain localization, whether localization can be observed with better analytic tools, and whether evidence for basic emotions exists in other types of measures. We then revisit the issue of whether the key hypotheses of psychological construction are supported by our meta-analytic findings. We close by elaborating on commentator suggestions for future research.

Frost's critique reveals the limitations of the reverse-engineering approach to cognitive modeling – the style of psychological explanation in which a stipulated internal organization (in the form of a computational mechanism) explains a relatively narrow set of phenomena. An alternative is to view organization as both the explanation for some phenomena and a phenomenon to be explained. This move poses new and interesting theoretical challenges for theories of word reading.

This commentary seeks to clarify the potential discrepancy between lab-based and field data in the use and effectiveness of punishment to promote cooperation by recommending theory that outlines key differences between the lab and field, such as the shadow of the future and degree of information availability. We also discuss a recent meta-analysis (Balliet et al. 2011) that does not support all conclusions outlined in Guala's target article.

Investigation of the cerebral organization of cognition in modern humans may serve as a tool for a better understanding of the evolutionary origins of our unique cognitive abilities. This commentary suggests three approaches that may serve this purpose: (1) cross-task neural overlap, referred to by Vaesen; but also (2) co-lateralization of asymmetric cognitive functions and (3) cross-functional (effective) connectivity.

Lab experiments on punishment are of limited relevance for understanding cooperative behavior in the real world. In real interactions, punishment is not cheap, but the costs of punishment are of a different nature than in experiments. They do not correspond to direct payments or payoff deductions, but they arise from the repercussions punishment has on social networks and future interactions.

Vaesen asks whether goal maintenance and planning ahead are critical for innovative tool use. We suggest that these aptitudes may have an evolutionary foundation in motor planning abilities that span all primate species. Anticipatory effects evidenced in the reaching behaviors of lemurs, tamarins, and rhesus monkeys similarly bear on the evolutionary origins of foresight as it pertains to tool use.

Languages and writing systems result from satisfying multiple constraints related to learning, comprehension, production, and their biological bases. Orthographies are not optimal because these constraints often conflict, with further deviations due to accidents of history and geography. Things tend to even out because writing systems and the languages they represent exhibit systematic trade-offs between orthographic depth and morphological complexity.