Evolutionary socioecological theory and research proposing linking parasites with human social organization is uncommon and therefore welcome. However, more generally, condition-dependent adaptive phenotypic plasticity requires environmental uncertainty on a small scale, accompanied by reliable cues. In addition, genes in parasites may select among biologically adaptive cultural alternatives directly without necessarily going through human genetic predispositions, resulting in inter-specific gene-culture coevolution.

A universal property of visual word identification is position-invariant letter identification, such that the letter “A” is coded in the same way in CAT and ACT. This should provide a fundamental constraint on theories of word identification, and, indeed, it inspired some of the theories that Frost has criticized. I show how the spatial coding scheme of Colin Davis (2010) can, in principle, account for contrasting transposed letter (TL) priming effects, and at the same time, position-invariant letter identification.

Strong reciprocity theorists claim that punishment has evolved to promote the good of the group and to deter cheating. By contrast, weak reciprocity suggests that punishment aims to restore justice (i.e., reciprocity) between the criminal and his victim. Experimental evidences as well as field observations suggest that humans punish criminals to restore fairness rather than to support group cooperation.

We challenge the classic experience/expression dichotomous account of emotions, according to which experiencing and expressing an emotion are two independent processes. By endorsing Dewey's and Mead's accounts of emotions, and capitalizing upon recent empirical findings, we propose that expression is part of the emotional experience. This proposal partly challenges the purely constructivist approach endorsed by the authors of the target article.

Guala points to a discrepancy between strong negative reciprocity observed in the lab and the way cooperation is sustained “in the wild.” This commentary suggests that in lab experiments, strong negative reciprocity is limited when uncertainty exists regarding the players' actions and the intentions. Thus, costly punishment is indeed a limited mechanism for sustaining cooperation in an uncertain environment.

Vaesen disregards a plausible alternative to his position, and so fails to offer a compelling argument for unique cognitive mechanisms. We suggest an ecological alternative, according to which divergent relationships between organism and environment, not exotic neuroanatomy, are responsible for unique cognitive capacities. This approach is pertinent to claims about primate cognition; and on this basis, we argue that Vaesen's inference from unique skills to unique mechanisms is unwarranted.

Here, I argue that Dixon et al. have overstated the prevalence of “benevolent” forms of prejudice; many stigmatised groups are currently the targets of overtly hostile evaluation and treatment by others (e.g., Muslims; immigrant groups). I also believe that the target article oversimplifies its presentation of prejudice researchers' primary theoretical and policy goals and that it overlooks important work in intergroup emotions.

There are universals of language; but is it also true, as the target article claims, that there are universals of reading? We believe there are no such universals, and invite others to refute our claim by providing a list of some universals of reading. If there are no universals of reading, there cannot be a universal model of reading.

The target article gives two explanations for the correlation between pathogens, family ties, and religiosity: one highlights the benefits of xenophobic attitudes for reducing pathogen exposure, the other highlights the benefits of ethnic loyalty for mitigating the costs when a person falls ill. Preliminary data from traditional societies provide some support for the former explanation but not the latter.

Lindquist et al. present a strong case for a constructionist account of emotion. First, we elaborate on the ramifications that a constructionist account of emotions might have for psychiatric disorders with emotional disturbances as core elements. Second, we reflect on similarities between Lindquist et al.'s model and recent attempts at formulating psychiatric disorders as networks of causally related symptoms.

Human tool behavior is species-specific. It remains a diagnostic feature of humans, even when comparisons are made with closely related non-human primates. The archaeological record demonstrates both the deep antiquity of human tool behavior and its fundamental role in distinguishing human behavior from that of non-human primates.

In matters of the mind, the opposition between what is mind-made or inside and natural or outside the mind is bound to misfire. Lindquist et al. build their analysis on a strong contrast between naturalism, which they reject, and psychologism, which they endorse. We challenge this opposition and indicate how adopting psychologism to combat a naturalistic view of emotional mind/brain areas is self-defeating. We briefly develop the alternative view of emotions as mental organs.

Hunter-gatherer punishment involves costs and benefits to individuals and groups, but the costs do not necessarily fit with the assumptions made in models that consider punishment to be altruistic – which brings in the free-rider problem and the problem of second-order free-riders. In this commentary, I present foragers' capital punishment patterns ethnographically, in the interest of establishing whether such punishment is likely to be costly; and I suggest that in many cases abstentions from punishment that might be taken as defections by free-riders are actually caused by social-structural considerations rather than being an effect of free-rider genes. This presentation of data supplements the ethnographic analysis provided by Guala.

Within the same pathogen-stress framework as proposed by Fincher & Thornhill (F&T), we argue further that pathogen stress promotes matrilocal rather than patrilocal family ties which, in turn, slow down the process of modernity; and that pathogen stress promotes social learning or copying, including the adoption of foreign religions.

I argue, contra Frost, that when prime lexicality and target density are considered, it is not clear that there are fundamental differences between form priming effects in Semitic and European languages. Furthermore, identifying and naming printed words in these languages raises common theoretical problems. Solving these problems and developing a universal model of reading necessitates “cracking” the orthographic input code.

Our research on non-religion supports the proposed shift toward more interactive models of prejudice. Being nonreligious is easily hideable and, increasingly, of low salience, leading to experiences not easily understood via traditional or contemporary frameworks for studying prejudice and prejudice reduction. This context affords new opportunity to observe reverse forms of interactive prejudice, which can interfere with prejudice reduction.

Reading development is integral to a universal model of reading. Developmental research can tell us which factors drive reading acquisition and which are the product of reading. Like adult research, developmental research needs to be contextualised within the language and writing system and it needs to include key cross-linguistic evaluations. This will create a universal model of reading development.

Experiments are not models of cooperation; instead, they demonstrate the presence of the ethical and other-regarding predispositions that often motivate cooperation and the punishment of free-riders. Experimental behavior predicts subjects' cooperation in the field. Ethnographic studies in small-scale societies without formal coercive institutions demonstrate that disciplining defectors is both essential to cooperation and often costly to the punisher.

Although the target article provides strong evidence against the locationist view, evidence for the constructionist view is inconclusive, because co-activation of brain regions does not necessarily imply connectivity between them. We propose a rigorous approach wherein connectivity between co-activated regions is first modeled using exploratory Granger causality, and then confirmed using dynamic causal modeling or Bayesian modeling.

Re-analysis of the data provided in the target article reveals a lack of evidence for a strong, universal relationship between parasite stress and the variables relating to sociality. Furthermore, even if associations between these variables do exist, the analyses presented here do not provide evidence for Fincher & Thornhill's (F&T's) proposed causal mechanism.