Articles & Essays Book Reviews

Gary Hatfield and Holly Pittman, eds. Evolution of Mind, Brain, and Culture. Philadelphia: U of Pennsylvania Museum of Archaeology and Anthropology, 2013. Hardcover, 496 pgs. $69.95U.S. ISBN: 9781934536490.

Reviewed by

Gregory F Tague

St. Francis College (N.Y.)

Recently there have been more than a few excellent books on the evolution of culture (some by the authors represented in the title under review), and we now have an impeccably edited and thoroughly researched volume covering all the main bases, edited by Gary Hatfield (philosophy, U Pennsylvania) and Holly Pittman (history of art, U Pennsylvania and Curator, Near East Section, U Pennsylvania Museum of Archaeology and Anthropology). Hatfield and Pittman’s volume is a user-friendly book offering a variety of perspectives on interrelated hominin evolutionary subjects drawing from disciplines such as psychology, biology, neuroscience, and environmental science. Evolution of Mind, Brain, and Culture is a required addition to any library collection on human evolution and cultural studies, especially in terms of the nature of the human mind as an evolved, adaptive mechanism. While some parts of some chapters can be theoretically abstract, and while in a large volume such as this there is inevitable overlap and some repetition (perhaps then in this review), Hatfield and Pittman’s book should be considered mandatory study for anyone seriously interested in evolutionary cultural studies: it is well organized, each chapter is clearly and carefully written by an expert in his or her field, and there are useful illustrations in addition to a thorough bibliography and index.

Before looking at each chapter, some in detail some not, let the preliminary observations flow from Hatfield’s Introduction. While other species have debatable culture, such as potato washing of Japanese macaque monkeys, insect probes of chimpanzees, and singing of whales, human culture is obviously deeper and broader, which begs many questions as to origins, says Hatfield. Since the mind is functional, what then are the evolved purposes of many cultural manifestations? There are cognitive capacities that arise from our inherited biology, and then there are those capacities that develop culturally. Hatfield leans to and in fact favors Richard Klein, providing a good overview and summary of parts of The Human Career (9). This is noteworthy since later in the book April Nowell will lean to and favor the Sally McBrearty and Alison Brooks (2000) paper that questions the validity of Klein’s neural leap in Homo sapiens of about 50kya.

Like Klein and others, the notion of branching (derived from Darwin’s single diagram in Origin of Species) is a fundamental concept to human development, and so we can see that there are homologies in humankind going back a few hundred million years. Such homologous structures include, Hatfield notes, “photosensitive pigments in the eyes . . . frontal eye sockets . . . limb autonomy . . . grasping extremities . . . opposable thumb . . .” (7) to name only a few. Certainly Hatfield and the other authors in the volume are looking at the big picture and a broad expanse of prehistory, so the individual is not really a factor. Thus, Hatfield can say with confidence that culture is less genetic and more environmental, that humankind creates its own environment and special niches into which each one of us is born.

Such thinking, historically, echoes the Lamarckian elements in later Darwin and recently the Darwinian model of cultural evolution. Perhaps the hallmark of being human is just the ability to evolve and develop through culture and not only through biology. There might be a trend that affects neural patterns, and that is biological; but the originating push to such a trend might not have been biological. There might have been selection for values and beliefs which would instance the co-evolution of genetic and cultural matter.

There are four types of social learning, according to Hatfield. First, in the words of Michael Tomasello, there is “stimulus enhancement” where one is cued to an outcome because of the environment. Second, there is emulation of another’s behavior to achieve a similar outcome. Third, there can be exact copying of another’s movement, which therefore involves motor imitation. And fourth, there can be an occasion where one intervenes actively to instruct another, meaning that intentionality is involved (14-15). Some non-human animals behave in such a way to suggest social (and not necessarily genetic) learning. However, there is a marked difference when it comes to human beings and chimpanzees. Regarding “tool design,” chimpanzees are not capable of making or transmitting “improvements” (16). Only human beings, Hatfield reminds us, have been able to evolve teaching and learning that substantially develops from stone tools and culture, to hunting, to agriculture, and eventually to cities.

While other species (chimpanzees and wolves, for instance) can form groups, they lack the complex, multi-layered cooperative, goal-centered abilities of human beings. Middle Pleistocene (780-127kya years ago) Neanderthals and sapiens, separately, engaged in highly coordinated “game drives” that presuppose some type of linguistic capability, which only followed from cooperative behaviors that had evolved much earlier (17). Over the course of human brain evolution, the occipital lobe (visual processing) shrank in proportion to an increase in the parietal lobe (integration of senses). Over the past seven million years chimpanzees have had more evolutionary change than human beings and so have probably lost more of whatever our shared common ancestor had (23). Hatfield offers a comprehensive survey of evolutionary approaches to mind and behavior after Darwin through the twentieth century (26-32).

For example, Hatfield cites Seyfarth and Cheney (represented in this volume) who suggest that baboons are capable of “conceptual knowledge” stemming from social capacities which over time served as the basis for linguistic capabilities (24). Other theories of mind/brain evolution include Merlin Donald (in this volume), who sees parallels among “motor coordination, representation, and planning”; those such as Tomasello lay importance in theory of mind; Carruthers (in this volume) sees “creativity” and “inferential abilities” in terms of cooperation as a combined, crucial adaptation; and then there is Mithen (in this volume) who lays stress on Gardner’s multiple intelligences which evolve into cognitive fluidity (25). Hatfield also offers an overview of the field from the essentially gene-based sociobiology of E.O. Wilson, to the cultural evolution of Boyd and Richerson (in this volume). He also looks at the evolutionary psychology of Cosmides and Tooby who look for explanations of human adaptation and behavior not in genes or culture but in how brain modules changed according to the environment of evolutionary adaptedness in the long Pleistocene. Hatfield also cites the human behavioral response to a changing ecology (Sterelny this volume). Thus, Hatfield rightly points out that there are, in addition to these few widely diverse views noted, debates in general about human “cognitive or psychological bases . . .” (40).

Let’s now take a look at the individual chapters.

Theodore Schurr (anthropology, U Pennsylvania) in his chapter asks “When did we become human?” Researchers are beginning to conclude that traits such as culture and tool use previously thought to be exclusively human are really “elaborations of similar features in other species . . .” (45). For instance, apes have underlying capacities and abilities for language and symbolism, and they are able to communicate vocally (47). Frans de Waal, Schurr notes, has drawn parallels between human language and the vocal and gestural manifestations of chimps and bonobos.

Did the human brain simply evolve cognitively, or from sociality, or tool manufacture and use? We should not be surprised to see that our nearest cousins, the chimpanzees, exhibit concerted, though primitive, tool use. Part of the problem about human evolution is that there is no linear descent, and even Darwin talks of branching and the imperfection of the fossil record. For instance, there is a debatable hominin species, Sahelanthropus tschadensis, from seven million years ago which shows clear evidence of bipedalism, much earlier than previously thought (49). There is still debate on the species that originates the homo line, an overview of the various species and their evolutionary contributions provided by Schurr (53).

In the branching model features are “mixed and matched,” implying that homoplasies, such as bipedalism or brain size, could have erupted and declined in any number of species (54). In other words, there might not be (or there is no way to find out) the so-called missing link. Without completely interpreting the statistic, Schurr says that the hominin population was significantly reduced after it split from the line that connected it to the chimpanzee (62-63). Is one inference that the trade-off (adaptive advantage) was so great as to shrink the population?

Key genetic changes in the homo lineage affected olfaction, bipedalism, diet, hearing and vocalization. Almost fifty genes implicated in olfaction have undergone change (and obviously we rely on the sense of smell very little) (65). For bipedalism there were many physical changes from, to name only a few, the pelvis and the lumbar. No matter when homo began to be completely bipedal, the adaptations had been continual and significant (67). Dietary change, as per the savanna hypothesis (fewer trees led to scavenging carcasses and very basic hunting), led to more carnivory (where, ultimately, in comparison with chimpanzees, human beings have a shorter large intestine and a longer small intestine). Other writers (such as Klein in The Human Career) offer extensive detail about hunting, but Schurr’s point seems to be that the dietary change of about 2.5mya might have led to more cooperation and coordinated efforts (not seen in chimpanzees) which could have prompted some form of communication (72). Of course it is at this time that early Stone Age tools begin to appear, presumably for butchering (though hunting is still unsophisticated). Could the quantity of such tools have been produced by a species that did not communicate with each other?

The FOXP2 gene (forkhead-box P2 transcription factor, if you must know) is crucial to human speech production and comprehension and probably occurs in modern humans at approximately 200kya (72). But this estimate does not preclude other forms of communication that might have a deeper prehistory. Apparently, Schurr notes, this gene has a similar form, related to motor skills, in other vertebrates, and certainly one gene alone is not responsible for language. There might be some correlation between brain size and full language, but even small-brained species exhibit the ability to communicate with those they recognize, a social function (79). In fact, while many authors stress encephalization, Schurr points out that in the human genome there are genes for microcephaly to restrict brain growth.

In the next chapter, Jody Hey (geneticist, Rutgers U) employs genetics to investigate the origins of the modern human brain. For example, on the one hand human cognition and sociality differ in degree among people because of a genetic basis, and, on the other hand, there are advanced capacities and sophisticated abilities belong only to human beings (92). The human brain, Hey notes, “expresses” up to 75% of every gene in some way, implying that human DNA has been adapted in terms of brain proteins (93). Evidence suggests that human adaptations occur between 6mya to 50kya, and then between 200kya to 50kya (97). However, Hey notes that sequencing human DNA is problematic since there is no indication of any gene’s impact on “development,” and even so the sequence concerning adaptation will probably not show “trait differences” before and after adaptation (98).

Hey goes on to note that because 10% of human “protein coding” genes experienced adaptation since the split from the human and chimpanzee ancestor, and since the human genome has approximately 25,000 protein coding genes, about 2,000 human genes have evolved over 6my. Moreover, there are probably a number of “beneficial mutations” adapted for that will simply not be measured (98-99). Over the same period of time chimpanzees have actually experienced more genetic adaptation, so we can locate adapting genes but not know which traits are selected for. Take the FOXP2 gene which evolved gradually as an amino acid, implying that it had been present in some form for much of our prehistory, and then jumped to maturity around 200kya in the hominin branch where, compared with chimpanzees, this gene affects about 100 additional genes (103).

In their paper, Robert Seyfarth (psychology, U Pennsylvania) and Dorothy Cheney (biology, U Pennsylvania) discuss the primate mind before tools, language, or culture. While obvious, it is worth stating (as others have): the first occurrence of a trait or artifact is not necessarily the first instance, so that while the basic tools appear at about 2.5mya the mind and behavioral traits that produce those tools had been developing pre-adaptations (105). Seyfarth and Cheney try to look back to a hominin mind before cultural artifacts, when sociality and communication were emerging (106).

Both Seyfarth and Cheney work with baboons, which have many types of socially contextual vocalizations. The authors posit that there were important vocalizations before cultural language. Some of their research demonstrates, for instance, that baboons can form and understand “a social narrative,” which reveals cognition in tune with subtle and graded tones (108). Without language, animals are able to form perceptions of individuals from sounds and gestures, and Seyfarth and Cheney go on to suggest that the concept of personhood is therefore very evolutionarily old. This sense of a person permits animals, particularly baboons, to posit theories and “predictions” about another’s behavior (112). Based on their studies, baboons are able to classify each other through abstractions, as if each has an individual character (113).

Thierry Chaminade (neuroscience, Aix-Marseille U), challenges statements about so-called mirror neurons, of which, strictly speaking, there are not many, and offers, instead “the concept of ‘motor resonance’ . . .” (124). The implications of Chaminade’s findings affect accepted beliefs about social learning. A mirror neuron creates a physical response; but such physiological reaction is really via a premotor neuron. Research demonstrates that only 6.5% of observed acts and only 5.5% of executed acts are truly the result of mirror neurons (128).

We simply cannot prove “direct correspondence” between a mirror neuron and an action, and most of what are called mirror are really premotor neurons reacting to observed action (129-130). Chaminade admits, though, that these findings come from research done on captive monkeys working with human caregivers, and then speculation arises as to how this works in human beings. His point is that neural areas related to the observation and the execution of action are not housed in particular neurons but are widely distributed (133). The brain’s connecting visual and tactile experiences, in this regard, is not truly a mirror but more a motor effect that enables neuroplasticity and hence learning (139). Chaminade’s idea is that, from an evolutionary standpoint, the brain’s capacity for motor skills and not necessarily for abstraction is what led to tool manufacture.

Felix Warneken (psychology, Harvard U) focuses on the origins of cooperative behavior and finds that individual and collaborative helping are different forms of cooperation. Much depends on how well an individual can determine another’s intentions, for without understanding intentions there is no personal motive or altruistic need to help. Strictly speaking, cooperation involves agents who can respond to each other, who understand each other’s goals, and who wish to share a common outcome (154). Infants as young as one year old are able to distinguish purpose from accident and can even estimate another’s intention, and in many such controlled experiments infants spontaneously help adults though no reward is forthcoming (155-156). All such experiments continue to reveal that there are innate helping and caring mechanisms as part of being human.

From an evolutionary perspective, research and observation of chimpanzees reveals that these animals are not completely self-interested and will act in altruistic ways when there is no clear benefit in sight. Perhaps this is not surprising given that the chimpanzees in question were raised by and often around human caretakers. But, Warneken goes on, some wild-born chimpanzees living in a Ugandan sanctuary with very little human contact were tested, and they too expressed helping behaviors even when no reward was expected, and in some cases they helped at increased cost to themselves (162). Warneken believes that altruism is not solely a human trait and that chimpanzees clearly exhibit “social-cognitive skills” in deciding whether or not to help (163). Studies by Warneken (working with Tomasello) question the prevailing notion that altruism is a learned behavior (167) since such is seen in infants and in chimpanzees long before the effects of socialization. Evidence of altruistic behavior early on (and again, in chimpanzees) indicates its evolved, biological foundation, later nurtured by social culture (168).

Two chapters of the book, one by Merlin Donald and another by Steven Mithen, re-examine ideas and theories from over a decade before. For his part, Donald (psychology and neuroscience, Queen’s U, Canada and Case Western Reserve U), takes a second look at his mimesis theory, a “neuro-cognitive adaptation” over two million years ago, originally related to tool manipulation, that enabled a “mindsharing culture” to form and eventually flourish (169). Donald emphasizes that the evolution of human cognition would certainly not be limited to one cause. The employment of skills would be tied to any number of complex events and factors related to, for example, eating, mating, and sociality (170-171).

Apes (bonobos, chimpanzees, and gorillas) do not have the human cognitive “symbolic processing,” epigenetic mechanisms, or sophisticated group thinking, and these unique qualities are tied somehow to his notion of “archaic mimetic adaptation” (173). In terms of language (and contrary to any separate modules as per Fodor or Chomsky), Donald says that neuroscience clearly shows that during brain evolution any brain area might have been operating for various capacities so that hominin language turns out to be a “’kluge’ cobbled together . . .” after other brain adaptations (176). Advanced language is a much later development, but Donald’s point seems to be that without language, and perhaps with only gesticulation and vocalization, the ability to choose which stones for use, and then to share knapping, striking angles, and the sharpening of the blade edge was transmitted by mimesis. In this way, learning is shared cognition.

Peter Gärdenfors (cognitive science, Lund U, Sweden), writes how cooperation plays a role in the evolution of language. That is, cooperation rather than gossip, sexual selection, or the Machiavellian mind, was the factor driving the evolution of language (194). For instance, indirect reciprocity (A helps B helps C) implies communication, and for evolving hominins, the changing and challenging environment encouraged proto and then full language (195). Gärdenfors believes the duration of immaturity in both ape and human infants is crucial to the test and play development of mind (196), cognitive functions related to mind reading and language.

Whereas other animals respond to drives (hunger) and instincts (storing food), human beings truly organize future plans, and it is this forward-looking capacity that is particularly linked to cooperative behaviors, no doubt blossoming in the fluctuating environment of evolutionary adaptedness (197). Cognitive adaptations directly related to long-term planning include intersubjectivity, a term preferred over theory of mind since the former denotes “joint attention” where the latter only implies mental guesswork (201). We cannot only guess another’s intention but we can also share intentions, and such mental cooperation, from a very early age, is what constitutes human goal making.

Steven Mithen (archaeology and environmental sciences, U Reading, UK) revisits his theories of cognition from his 1996 book The Prehistory of the Mind. Drawing from Gardner’s intelligences and Cosmides and Tooby’s modules, Mithen postulates that separate brain functions, e.g. for sociality, hunting, and tool making, eventually began to shift from domain specific rigidity (hunt=bone) to flexibility (hunt=bone=tool OR hunt=bone=personal adornment). While Mithen convincingly (here and especially in PHM) limits any such cognitive fluidity in ergaster and nearly negates any such in Neanderthals, he labels McBrearty and Brooks’ (2000, Journal of Human Evolution) article, “The Revolution That Wasn’t,” as “controversial.” Mithen sees no cognitive fluidity among Neanderthal intelligences, so that decorative beads cannot flow from social or technical intelligence, spears cannot flow from natural or technical intelligence, and cave art cannot flow from social or natural intelligence (222).

Mithen sees full consciousness and cognitive fluidity as a very late post-Neanderthal development. So one can see how Mithen would debate McBrearty and Brooks (supported by April Nowell in this volume) who marshal quite a bit of physical evidence to claim that Mithen and others (e.g., Klein’s neural event of circa 50kya) are wrong in setting a late, sudden shift in hominin brain organization. McBrearty and Brooks demonstrate that some modern social and cognitive behaviors go back as far as 300kya and certainly include Neanderthals.

Mithen boils down evolution of mind to three theories. First, there is the social brain hypothesis of Dunbar, where gossip plays a key role in the development of language and where theory of mind and social interactions foster complex relationships. These ideas are crucial to Mithen since they elaborate his social intelligence which is important for both domain specificity and, later, cognitive fluidity (227). The social brain hypothesis does not account for technical improvisations, such as tool use, or explain why at approximately 70kya there is symbolic culture (though modern brain size appears at 250kya). Second, there are Wynn and Coolidge, who claim that modern humans, not Neanderthals, have greater short term memory (227). This idea also supports Mithen and cultural developments in the Middle Stone Age with cognitive flexibility. Third, Geoffrey Miller emphasizes sexual selection (via Darwin) as the driving force behind mind and creativity but without reference to the archaeological record and with no chronology. Mithen calls Miller’s argument “persuasive” though not “integrative” (227-228). Ultimately, Mithen sees the physical, artifactual culture as potentially responsible for instigating cognitive fluidity and certainly for promoting and extending mind sharing (232).

April Nowell (anthropology, U Victoria, BC) examines the cognitive and behavioral evidence from the Middle and Early Upper Paleolithic area. For Nowell, cognitive means “phonemic, syntactical, and symbol based language . . .” as well as what psychologists and neuroscientists might call the understanding of oneself, theory of mind, memory, and forethought (235). Clearly these are all adaptive advantages, and Nowell, drawing heavily from McBrearty and Brooks, focuses on Neanderthals and anatomically modern humans (AMHs) to define and contextualize them and what constitutes modern behaviors such as “abstract thinking . . . planning depth . . . behavioral, economic, and technical innovations . . . symbolic behavior” (236).

In terms of cognition and behavioral modernity Nowell rehearses Mithen (cognitive fluidity that permits domains to interact), Klein (neural leap circa 50kya), McBrearty and Brooks (modern human behavior as part of a branching of species going back at least 200kya), and Coolidge and Wynn (who emphasize as modern behaviors “enhanced working memory” or the sequencing and “integration” of data over time) (237-238). Nowell draws close parallels between Neanderthals and AMHs in, e.g., dentition, brain growth, sexual maturation (240), and of course the question of interbreeding and gene flow appears. She does not cite the Kay Prüfer (Svante Pääbo team) Nature article of 2013 that discusses the Neanderthal genome sequence, but most likely since the paper was not available in time.

If genes flow two ways, why did the Neanderthals not benefit from AMHs? Without directly saying so, Nowell seems to suggest, but does not assert, that the cognitive differences between Neanderthals and AMHs is exaggerated (241) and that the differences might have been more cultural with obviously fatal consequences for the Neanderthals. To build a case regarding the similarity between Neanderthals and AMHs, Nowell uses a template from McBrearty and Brooks that covers ecology, technology, social organization, and symbolic behavior. Because of space limitations, the fruits of Nowell’s research are excluded here, but suffice it to say there is plenty of evidence, especially in technology and symbolic behavior, that pushes the definition of modern much further back than 70kya.

The upshot of Nowell’s work is that Mithen’s assertion of Neanderthal cognitive constraint, i.e. domain specificity without cognitive fluidity of later people, is off the mark in light of all the factual evidence now assembled, especially from McBrearty and Brooks. Since the four criteria merely mentioned are met by older people, “the capacity for modern behaviors could not be the result of a speciation event 160,000 years ago” (257). Instead, what seems like a cultural explosion at 70-50kya might be the result of a series of contractions from the eruption of Mt. Toba, at 71kya, and glaciation for up to 10,000 years, forcing a sudden drop in cultural production and advance, to be picked up later (259).

Peter Richerson (environmental sciences, U California, Davis) and Robert Boyd (anthropology, U California, Los Angeles), a team known for many collaborative projects in cultural/gene co-evolution, not least of all the book Not By Genes Alone, write about paleoanthropology and ask why, considering its importance in so many aspects of human life, the brain did not evolve more fully earlier? The short answer has something to do with two types of evolutionary forces: micro evolution (small and fast) and macro evolution (large and slow). The changes within mammal brains have been occurring for 65my while undergoing variation due to climate changes (264). A secondary question concerns the types of “processes” affecting evolutionary change and on which particular “time scales” (266). In other words, Richerson and Boyd suggest that not all emphasis should be on internal, micro, slow evolution.

There might be other reasons and causes to explain some rather sudden developments. Critical to this discussion, there might be more of a question as to when selection seems to favor a development (such as a larger brain) (266). On scale, all vertebrate brains are similar, and nature would prefer a smaller brain since it grows faster and takes much less energy to operate and maintain (e.g., dinosaurs) (266-67). Many mammals have experienced recent brain growth, so there is probably some “common external environmental change . . .” catalyzing this increase.

While social learning as well as genetics explain brain growth, and studies demonstrate that there is a balance between “innovation and brain size” (272), Richerson and Boyd nevertheless correlate brain/culture development with climate changes (273). During the age of mammals, from 65mya onward, there have been a series of different climates, with the trend increasingly cooler and drier, so that by about 3mya there are ice ages (275). Stone tools appear at 2.5mya, and brain encephalization shortly thereafter. Then from 1mya there were one hundred 1000-year long “glacial cycles” related somewhat to the earth’s axis wobble but more so to the “ocean-atmospheric-ice sheet” system (275). These developments were in turn connected to the range of the sea floor via continental shift and splurge of mountains, all of which affects wind and ocean currents (276).

There was a sudden shift 14,650ya from cold to interglacial warmth (278), and data seem to reveal that while glacial periods have the “variable climates” interglacials do not (280). Richerson and Boyd are clear that these extreme environmental variations correlate to their theory of brain development. That is, contrary to Klein and Mithen, they take an externalist and not an internalist approach and so, like McBrearty and Brooks, they challenge prevailing views about human evolution by imagining modern cognition and behavior well before the usual circa 50kya turning point (282). This means that Richerson and Boyd see the Upper Paleolithic developments in technology as cultural and not biological (genetic) (283). Toolkit sophistication, then, might have as much, or more, to do with climate and demographics than cognitive advances (290-291).

Kim Sterelny (philosophy and social science, Australia National U) examines Human Behavior Ecology (HBE) which emphasizes “the adaptive flexibility of human behavior . . .” so that “our learning and decision mechanisms equip us to respond successfully to a broad range of environments” such as the adoption of agriculture over foraging (303).

Sterelny notes how evolutionary psychologists are not fond of HBE because there is the question of whether or not “current behavior is adaptive,” i.e., evolutionary psychologists are more to cognitive adaptation in “past environments” (305). What then of birthing decisions (the timing) in comparison to food resources, Sterelny asks? In other words, there is a connection between fitness and a complex organism’s capacity to act adaptively, to take advantage of environments and circumstances.

But HBE is not without criticism from Sterelny. For instance, in some cases there is the implication, especially for human evolution, that unless we change in accordance with a changing environment we suffer, and this attitude overlooks how hominins have had the ability to shape their own environments in spite of external changes forced upon them (310). Sterelny’s point is that through millennia, homo sapiens have clearly optimized resources and circumstances “over a wide range of environments . . .” (312).

Peter Carruthers (philosophy, U Maryland), sees “multiple adaptations” as responsible for a cumulative culture. He lists eight factors or “systems” working independently, and he is not really concerned with any chronology of cognitive adaptations, drawing rather from the module model of evolutionary psychologists but “negatively,” by showing that there were a number of different adaptations and not just one or two “new capacities” (325-326).

Carruthers is more in line with Tomasello (the ratchet effect of learning and innovation) concerning the expansive growth of culture, but he sees such developments arising from many adaptations (327). The eight human adaptive systems are as follows, and for space considerations are only listed.

Imitation, shared intentionality, and mind reading (citing McBrearty and Brooks); Language; Creativity; Fine motor coordination (citing Donald); Physics (i.e., physical understanding); Inference to the best explanation; Cooperation and norms; Further adaptation to culture (citing Richerson and Boyd).

In the final chapter, Philip Chase (archaeology and anthropology, U Pennsylvania, Penn Museum) claims that human culture is more than memes and simple transmission and stems, rather, from concurrence or an “ability and willingness to create and to abide by agreements . . .” to a degree of social life not seen in other species (349). While Chase seems to lean to social constructivism with his insistence that cultural variation is independent of genes and is more dependent on “social learning” (where he positively cites Geertz), his point nonetheless seems to be that the social transmission model is “incomplete,” placing culture, instead, “in the mind” and not in behavior (351).

A “state of mind” and “intentions” are expressed and shared, and that is what instigates behavior (352). In this way there is an “intention pool” that is shared, altered, and even improved via concurrence or an agreement to share (352). However, this agreement “is not a property . . .” belonging to those who share intentions but is on another social plane and cannot therefore be completely changed but only negotiated into a new agreement by the two people (353-354), which can occur on a group level.

So we see that entire societies are “invariably organized by means of cultural concurrences . . .” (362). While human beings experience animal-like drives (hunger), unlike animals a cultural concurrence would consist of a sophisticated and goal-oriented game drive (363). Furthermore, cultural concurrences (e.g., values and beliefs) can originate “motivations” (363). Chase admits, though, that it is difficult to find evidence for the origins of concurrences (such as captive chimpanzees sharing human signs with other chimpanzees) (365). There seems to be evidence, though, that “cultural agreements” were an important factor up to 127kya, where endocasts suggest a vocal tract and other evidence exists for game drives (367). Brain size might have more to do with reorganization than with a higher functionality such as language, since in living human beings, brain size can vary greatly yet not affect language capability (368).

Like many others in this volume, Chase suggests that the evolution of mind, brain, and culture was not wholly genetic but occurred according to response variations in “local conditions” (377-378). Of course if these adaptations were selected for and provided survival and reproductive benefit, they became genetic.