In my response to the commentaries from a collection of esteemed researchers, I reassess and eventually find largely intact my claim that human tool use evidences higher social and non-social cognitive ability. Nonetheless, I concede that my examination of individual-level cognitive traits does not offer a full explanation of cumulative culture yet. For that, one needs to incorporate them into population-dynamic models of cultural evolution. I briefly describe my current and future work on this.

I argue that the study of variability rather than invariance should head the reading research agenda, and that strong claims of orthographic “optimality” are unwarranted. I also expand briefly on Frost's assertion that an efficient orthography must represent sound and meaning, by considering writing systems as dual-purpose devices that must provide decipherability for novice readers and automatizability for the expert.

In small-scale societies, punishment of adults is infrequent and employed when the anticipated cost-to-benefit ratio is low, such as when punishment is collectively justified and administered. In addition, benefits may exceed costs when punishers have relatively greater physical and social capital and gain more from cooperation. We provide examples from the Tsimane horticulturalists of Bolivia to support our claims.

Letter-position tolerance varies across languages. This observation suggests that the neural code for letter strings may also be subtly different. Although language-specific models remain useful, we should endeavor to develop a universal model of reading acquisition which incorporates crucial neurobiological constraints. Such a model, through a progressive internalization of phonological and lexical regularities, could perhaps converge onto the language-specific properties outlined by Frost.

To add ethnographic perspective to Guala's arguments, I suggest reasons why experimental and ethnographic evidence do not concur and highlight some difficulties in measuring whether positive and negative reciprocity are indeed costly. I suggest that institutions to reduce the costs of maintaining cooperation are not limited to complex societies.

Interest in orthographic processing reflects an expansion, not constriction, of the scope of research in visual word recognition (VWR). Transposition effects are merely one aspect of investigations into orthographic encoding, while open bigrams can accommodate differences across languages. The target article's inaccurate characterization of the study of orthographic processing is not conducive to the advancement of VWR research.

I argue in my target article that field evidence does not support the costly punishment hypothesis. Some commentators object to my reading of the evidence, while others agree that evidence in favour of costly punishment is scant. Most importantly, no rigorous measurement of cost-benefit ratios in the field has been attempted so far. This lack of evidence does not rule out costly punishment as a cause of human cooperation, but it does pre-empt some overconfident claims made in the past. Other commentators have interpreted my article as an anti-experimental pamphlet or as a flat denial of the existence of pro-social motives – which it was not intended to be. While we have enough data to establish the existence (and theoretical relevance) of strong reciprocity motives, I argue in this response that their efficacy (and policy relevance) has not been demonstrated.

I have argued that orthographic processing cannot be understood and modeled without considering the manner in which orthographic structure represents phonological, semantic, and morphological information in a given writing system. A reading theory, therefore, must be a theory of the interaction of the reader with his/her linguistic environment. This outlines a novel approach to studying and modeling visual word recognition, an approach that focuses on the common cognitive principles involved in processing printed words across different writing systems. These claims were challenged by several commentaries that contested the merits of my general theoretical agenda, the relevance of the evolution of writing systems, and the plausibility of finding commonalities in reading across orthographies. Other commentaries extended the scope of the debate by bringing into the discussion additional perspectives. My response addresses all these issues. By considering the constraints of neurobiology on modeling reading, developmental data, and a large scope of cross-linguistic evidence, I argue that front-end implementations of orthographic processing that do not stem from a comprehensive theory of the complex information conveyed by writing systems do not present a viable approach for understanding reading. The common principles by which writing systems have evolved to represent orthographic, phonological, and semantic information in a language reveal the critical distributional characteristics of orthographic structure that govern reading behavior. Models of reading should thus be learning models, primarily constrained by cross-linguistic developmental evidence that describes how the statistical properties of writing systems shape the characteristics of orthographic processing. When this approach is adopted, a universal model of reading is possible.

The science of genetics is undergoing a paradigm shift. Recent discoveries, including the activity of retrotransposons, the extent of copy number variations, somatic and chromosomal mosaicism, and the nature of the epigenome as a regulator of DNA expressivity, are challenging a series of dogmas concerning the nature of the genome and the relationship between genotype and phenotype. According to three widely held dogmas, DNA is the unchanging template of heredity, is identical in all the cells and tissues of the body, and is the sole agent of inheritance. Rather than being an unchanging template, DNA appears subject to a good deal of environmentally induced change. Instead of identical DNA in all the cells of the body, somatic mosaicism appears to be the normal human condition. And DNA can no longer be considered the sole agent of inheritance. We now know that the epigenome, which regulates gene expressivity, can be inherited via the germline. These developments are particularly significant for behavior genetics for at least three reasons: First, epigenetic regulation, DNA variability, and somatic mosaicism appear to be particularly prevalent in the human brain and probably are involved in much of human behavior; second, they have important implications for the validity of heritability and gene association studies, the methodologies that largely define the discipline of behavior genetics; and third, they appear to play a critical role in development during the perinatal period and, in particular, in enabling phenotypic plasticity in offspring. I examine one of the central claims to emerge from the use of heritability studies in the behavioral sciences, the principle of minimal shared maternal effects, in light of the growing awareness that the maternal perinatal environment is a critical venue for the exercise of adaptive phenotypic plasticity. This consideration has important implications for both developmental and evolutionary biology.

A number of recent developments in our understanding of the biology of heritability question commonly held views on the immutability of genetic factors. These have numerous potential implications for improving understanding and practice in pre- and postconceptional care and for infant and child mental health, and they carry a cautionary message against overgeneralization.

Several new molecular findings and concepts furnish evidence in support of gene–environment interdependence, challenging some of the current tenets and basic statistics of behavioral genetics. I, however, argue that (1) some of the expectations evoked by “neogenomics” are contradicted by findings; and (2) while epigenetic and gene expression effects are complex, they can to some extent be incorporated into “classical” behavioral genetics modeling.

Charney argues that the presence of inherited epigenetic effects makes twin, family, and adoption studies obsolete. This argument relies on both a faulty characterization of these studies and indirect comparisons of DNA and “neogenetic” factors. I argue that twin and family studies will in fact serve a necessary and vital role in the study of epigenetic and neogenetic processes.