There is considerable scope for developing a more explicit role for ethnography within the research program proposed in the article. Ethnographic studies of cultural micro-evolution would complement experimental approaches by providing insights into the “natural” settings in which cultural behaviours occur. Ethnography can also contribute to the study of cultural macro-evolution by shedding light on the conditions that generate and maintain cultural lineages.

Striedter's account of human brain evolution fails on two key counts. First, he confuses developmental constraints with selection explanations in the initial jump in hominid brain size around two MYA. Second, he misunderstands the Machiavellian Intelligence explanation.

Understanding the origins of evil behaviour is one of our most important intellectual tasks. A distinction can perhaps be drawn between overt sadistic cruelty and the lack of empathy to suffering that is a hallmark of evil. There is increasing data available on the prevalence, proximal psychobiological underpinnings, and distal evolutionary basis for these contrasting phenomena.

It is suggested that general-purpose cognitive modules are the proper endophenotypes on which evolution has operated, not special purpose belief modules. These general-purpose modules operate to extract adaptive cultural patterns. Belief in souls may be adaptive and based in evolved systems without requiring that a specific cognitive system has evolved to support just such beliefs.

Primary issues raised by the commentaries on the target article relate to (1) the need to differentiate distinct but overlapping aspects of fluid cognition, and (2) the implications that this differentiation may hold for conceptions of general intelligence. In response, I outline several issues facing researchers concerned with differentiation of human cognitive abilities and suggest that a revised and expanded theory of intelligence is needed to accommodate an increasingly diverse and varied empirical base.

Why are people interested in money? Specifically, what could be the biological basis for the extraordinary incentive and reinforcing power of money, which seems to be unique to the human species? We identify two ways in which a commodity which is of no biological significance in itself can become a strong motivator. The first is if it is used as a tool, and by a metaphorical extension this is often applied to money: it is used instrumentally, in order to obtain biologically relevant incentives. Second, substances can be strong motivators because they imitate the action of natural incentives but do not produce the fitness gains for which those incentives are instinctively sought. The classic examples of this process are psychoactive drugs, but we argue that the drug concept can also be extended metaphorically to provide an account of money motivation. From a review of theoretical and empirical literature about money, we conclude that (i) there are a number of phenomena that cannot be accounted for by a pure Tool Theory of money motivation; (ii) supplementing Tool Theory with a Drug Theory enables the anomalous phenomena to be explained; and (iii) the human instincts that, according to a Drug Theory, money parasitizes include trading (derived from reciprocal altruism) and object play.

We agree that supernatural beliefs are pervasive. However, we propose a more general account rooted in how people trace ordinary objects over time. Tracking identity involves attending to the causal history of an object, a process that may implicate hidden mechanisms. We discuss experiments in which participants exhibit the same “supernatural” beliefs when reasoning about the fates of cups and automobiles as those exhibited by Bering's participants when reasoning about spirits.

The nature of children's early environment has profound long-term consequences. We are beginning to understand the underlying molecular programming of the stress-response system, which may mediate the destructive long-term effects of cruelty to children, explain the evolutionary stability of cruelty, and provide opportunities for its reversal of early trauma.

Mesoudi et al.'s new synthesis for cultural evolution closely parallels the evolutionary synthesis of Neo-Darwinism. It too draws inspiration from population genetics, recruits other fields, and, unfortunately, also ignores development. Enculturation involves many serially acquired skills and dependencies that allow us to build a rich cumulative culture. The newer synthesis, evolutionary developmental biology, provides a key tool, generative entrenchment, to analyze them.

Although van der Velde's de Kamps's (vdV&dK) attempt to put syntactic processing into a broader context of combinatorial cognition is promising, their coverage of neuroscientific evidence is disappointing. Neither their case against binding by temporal coherence nor their arguments against recurrent neural networks are compelling. As an alternative, vdV&dK propose a blackboard model that is based on the assumption of special processors (e.g., lexical versus grammatical), but evidence from the cognitive neuroscience of language, which is, overall, less than supportive of such special processors, is not considered. As a consequence, vdV&dK's may be a clever model of syntactic processing, but it remains unclear how much we can learn from it with regard to biologically based human language.

Ritualized behavior, intuitively recognizable by its stereotypy, rigidity, repetition, and apparent lack of rational motivation, is found in a variety of life conditions, customs, and everyday practices: in cultural rituals, whether religious or non-religious; in many children's complicated routines; in the pathology of obsessive-compulsive disorders (OCD); in normal adults around certain stages of the life-cycle, birthing in particular. Combining evidence from evolutionary anthropology, neuropsychology and neuroimaging, we propose an explanation of ritualized behavior in terms of an evolved Precaution System geared to the detection of and reaction to inferred threats to fitness. This system, distinct from fear-systems geared to respond to manifest danger, includes a repertoire of clues for potential danger as well as a repertoire of species-typical precautions. In OCD pathology, this system does not supply a negative feedback to the appraisal of potential threats, resulting in doubts about the proper performance of precautions, and repetition of action. Also, anxiety levels focus the attention on low-level gestural units of behavior rather than on the goal-related higher-level units normally used in parsing the action-flow. Normally automatized actions are submitted to cognitive control. This swamps working memory, an effect of which is a temporary relief from intrusions but also their long-term strengthening. Normal activation of this Precaution System explains intrusions and ritual behaviors in normal adults. Gradual calibration of the system occurs through childhood rituals. Cultural mimicry of this system's normal input makes cultural rituals attention-grabbing and compelling. A number of empirical predictions follow from this synthetic model.

It is difficult to fully account for (1) cruelty in modern society and (2) female cruelty, referring only to a cruelty-satiation association. Instead it seems likely that cruelty acquires its reinforcing value via association with a range of reinforcers. In addition, when one's goal is violence prevention, it is important to identify causes that can be manipulated.

Bering's work provides new insight into the child's concept of the self. For his results indicate that children don't regard bodily identity as required for identity of self across time. Bering's methodology for investigating afterlife beliefs might also be exploited to explore the extent to which children think that psychological similarity is required for sameness of self.

As Striedter explores the concerted principles that drive brain evolution and the departures that create uniqueness, he scrutinizes and ultimately supports the (unnecessarily controversial) Finlay/Darlington model in which mathematical relationships across mammalian neural development are identified (Finlay & Darlington 1995). Pragmatic impact includes the ability to make novel comparisons across developing species, including humans.

Why are people interested in money? This question is too broad: there are many kinds of money, interest, and people. The biological approach of Lea & Webley (L&W) makes them seek the roots of this interest, and they contend that tool making and addiction qualify as the roots. Curiosity and the quest for power, however, qualify too. As L&W rightly admit, other approaches supplement their biological one.

We are encouraged that the majority of commentators endorse our evolutionary framework for studying culture, and several suggest extensions. Here we clarify our position, dwelling on misunderstandings and requests for exposition. We reiterate that using evolutionary biology as a model for unifying the social sciences within a single synthetic framework can stimulate a more progressive and rigorous science of culture.

We argue that ritual is not a by-product as Boyer & Lienard (B&L) claim, but rather an evolved adaptation for social communication that facilitates non-agonistic social interactions among non-kin. We review the neurophysiological effects of ritual and propose neural structures and networks beyond the cortical-striato-pallidal-thalamic circuit (CSPT) likely to be implicated in ritual. The adaptationist approach to ritual offers a more parsimonious model for understanding these effects as well as the findings B&L present.

An emotional value for money is clearly demonstrable beyond its value for getting goods, but this value need not be ascribed to human preparedness for altruism or play. Emotion is a motivated process, and our temptation to “overgraze” positive emotions selects for emotional patterns that are paced by adequately rare occasions. As a much-competed-for tool, money makes an excellent occasion for emotional reward – a prize with value beyond its tool value – but this is true also of the other facts by which we pace our emotions.

A Rousseauist bias towards the study of human aggression has treated it as a regrettable anomaly rather than a volatile reflection of important forces in human evolution. Intrepidly, Nell displays the arc of connection between predation in humans and other animals and the neurophysiological factors that underlie chronic interest in accident, death, and harsh force.

Given that natural selection is so powerful at optimizing complex adaptations, why does it seem unable to eliminate genes (susceptibility alleles) that predispose to common, harmful, heritable mental disorders, such as schizophrenia or bipolar disorder? We assess three leading explanations for this apparent paradox from evolutionary genetic theory: (1) ancestral neutrality (susceptibility alleles were not harmful among ancestors), (2) balancing selection (susceptibility alleles sometimes increased fitness), and (3) polygenic mutation-selection balance (mental disorders reflect the inevitable mutational load on the thousands of genes underlying human behavior). The first two explanations are commonly assumed in psychiatric genetics and Darwinian psychiatry, while mutation-selection has often been discounted. All three models can explain persistent genetic variance in some traits under some conditions, but the first two have serious problems in explaining human mental disorders. Ancestral neutrality fails to explain low mental disorder frequencies and requires implausibly small selection coefficients against mental disorders given the data on the reproductive costs and impairment of mental disorders. Balancing selection (including spatio-temporal variation in selection, heterozygote advantage, antagonistic pleiotropy, and frequency-dependent selection) tends to favor environmentally contingent adaptations (which would show no heritability) or high-frequency alleles (which psychiatric genetics would have already found). Only polygenic mutation-selection balance seems consistent with the data on mental disorder prevalence rates, fitness costs, the likely rarity of susceptibility alleles, and the increased risks of mental disorders with brain trauma, inbreeding, and paternal age. This evolutionary genetic framework for mental disorders has wide-ranging implications for psychology, psychiatry, behavior genetics, molecular genetics, and evolutionary approaches to studying human behavior.