#11. A Summary of ‘The Social Conquest of Earth’ by E.O. Wilson

‘The Social Conquest of Earth’ by E.O. Wilson (Liveright; April 9, 2012)

*A podcast discussion of this book is also available. To listen to the podcast click on the link below and press ‘play’.

The Podcast

*The podcast is also available for download on iTunes.

Table of Contents:

i. Introduction

PART I: EARLY HUMAN EVOLUTION: FROM THE BRANCHING-OFF OF HUMANS AND CHIMPS TO TRUE EUSOCIALITY

1. The Branching-Off of Humans and Chimpanzees

2. From Herbivorousness to Omnivorousness: The Addition of Meat to the Human Diet

3. The Evolution of Cooperation

4. Warfare

5. The Group-Level Selection Theory Controversy

6. The Controlled Use of Fire

7. Eusociality

8. Human Campsites/Nests

PART II: THE BIOLOGICAL EVOLUTION OF CULTURE: THE ORIGINS OF TRIBALISM, LANGUAGE, RELIGION AND ART

9. The Evolution of Tribalism

10. The Divided Psyche: Virtue and Vice

11. The Evolution of Language

12. The Evolution of Culture

13. Gene-Culture Co-Evolution

14. The Origins of Religion

15. The Origins of Visual Art, Music & Dance

PART III: EARLY CULTURAL EVOLUTION: FROM THE BEGINNINGS OF AGRICULTURE TO THE RISE OF CIVILIZATIONS

16. Early Agriculture

17. Advanced Agriculture, Chiefdoms & The Explosion of Culture

18. The Rise of Civilization: The First States

19. Conclusion

i. Introduction

Since the dawn of self-awareness we human beings have struggled to understand ourselves. This struggle has found form in religion, philosophy, art and, most recently, science. The most pivotal turning point in science’s quest to understand humanity came with Charles Darwin’s theory of evolution by natural selection in the mid 19th century. While the application of this theory to understand human behaviour has taken time (and engendered a great deal of controversy), enough progress has now been made to outline the story in full, and to fill in several of the details. It is just this task that legendary biologist E.O. Wilson takes up in his new book `The Social Conquest of Earth’.

For Wilson, understanding humanity must begin with an understanding of how we came to be the ultrasocial species that we are. Drawing upon evidence from other eusocial species (such as bees, wasps, termites and ants–the latter of which Wilson has spent much of his career studying), as well as numerous sciences focused in on humanity and its past, Wilson recreates this story. According to the author, the story reaches its first major turning point when our ancestors began establishing home-bases at which they raised their young, and near which they foraged and scavenged for food. This development itself was largely a result of a genetic modification that led our ancestors to rely more and more on meat in their diet (and was greatly spurred on by, if not entirely dependent upon, the ability to control fire, which fire was used to establish more lasting campsites).

Once human beings had established nests, environmental pressures began selecting for traits that increasingly drew group members into cooperative relationships with one another (which cooperation was beneficial in such enterprises as hunting expeditions). This added cooperation not only contributed to the extent to which these early humans could reap resources from the environment, but also helped them in competition with other groups–especially in warfare. The benefits of cooperation and cohesion in allowing groups to out-compete other groups eventually allowed group-level selection to add a layer of tribalist sentiment to the members of our species (which tribalist sentiment draws from us a deep attachment to our in-groups, and a corresponding mistrust and contempt for members of out-groups). This tribalist sentiment eventually set the stage for the development of the first religions. The cooperative and tribalist sentiments that evolved during this time ultimately explains why our psyches are torn between selflessness and selfishness, virtue and vice. (On the topic of group-level selection, it turns out that this theory has been out of favour in the scientific community for over 40 years, and a big part of Wilson’s purpose here is to resurrect the theory, and reestablish its credibility.)

Backing up in our story just a bit, for our in-group cooperation to occur, added mental equipment was needed (and evolved) that allowed humans to understand each others’ intentions and work together to achieve goals. This added mental ability drew upon earlier increases in brain capacity that our ancestors had used first for life in the trees, and later for life on the ground, to fashion rudimentary tools. Eventually, the added mental capacity evolved into the ability to understand abstraction, and to use arbitrary symbols for communication, thus leading to the evolution of language.

Once the capacity for abstraction and language were established, the capacity for culture exploded and our ancestors were set on the fast track that led to our current way of life. Specifically, the onset of language led to the development of religion, art and music, and all of the other trappings of culture that we know and enjoy today. Wilson takes us through each of them one by one, and the process of gene-culture co-evolution that acted upon them, in order to help us understand how this process unfolded. Later, the explosion of culture led to technology that gave rise to agriculture, and then to the rise of chiefdoms, and finally states and the first true civilizations.

What follows is a comprehensive summary of the main argument in E.O. Wilson’s ‘The Social Conquest of Earth’.

PART I: EARLY HUMAN EVOLUTION:

FROM THE BRANCHING-OFF OF HUMANS AND CHIMPS TO TRUE EUSOCIALITY

1. The Branching-Off of Humans and Chimpanzees

Our species branched off from our closest evolutionary ancestors, the chimpanzees, some 5 to 7 million years ago, so the key to understanding humanity lies in what has happened in the interim. Our branching off began, it is thought, when our ancient ancestors were pressured to emigrate from the rainforests of central Africa where we they had lived and evolved for tens of millions of years.

Even before this occurred though, our species had already begun to evolve many of the features that would later prove to be very important in the trajectory that we would take. To begin with, our nimble and versatile hands—that would later prove to be so crucial for making tools—were made possible by our ancestors evolving hands and feet that were capable of grasping the branches among which they made their living (loc. 441-45). Also, the big brains for which our species is famous had already begun to evolve in our arboreal ancestors, “perhaps,” Wilson explains “as an accommodation to the relatively complex manner and flexibility of their feeding behavior, and to the three-dimensional and open vegetation of their habitat” (loc. 448). This added brain capacity can, of course, be seen in other primates and apes today, especially the chimpanzee, our nearest evolutionary cousin.

With these adaptations in place our species was now set for the modification that would ultimately lead them out of the trees and onto the plains of Africa: bipedalism. Our primate ancestors had already begun to develop the ability to shift much of their weight to their legs when walking on flat ground, as can be seen in the ambling practice among many primates today (loc. 453). However, while our progenitors mainly used a ‘knuckling’ approach—wherein they supported their weight with the help of their arms, via the use of their knuckles—our ancestors developed the ability to walk fully upright, with arms swinging pendulously at their sides. The shift to bipedalism had several benefits. For one, it freed up the hands for other things (such as carrying objects over long distances, and, later, fashioning tools). Second, bipedalism allowed our ancestors to look out over much longer distances across the savannah to spot potential opportunities, as well as potential threats—such as the big cats of the plains (loc. 521).

Most important of all, though, bipedalism allowed our forbears to walk more efficiently over flat land (loc. 491). At first, this was useful for walking between trees, especially where the trees themselves were more spread out—such as at the fringes of the rainforests. Later, though, this adaptation allowed our ancestors to leave the trees for good, and venture out on to the plains and beyond; in fact, this shift may well have been forced upon them, as it is now known that “during the period of critical evolution, most of sub-Saharan Africa was in a dry epoch, during which the rainforests retreated toward the equatorial belt while shrinking into scattered strongholds in the north” (loc. 521).

 2. From Herbivorousness to Omnivorousness:

The Addition of Meat to the Human Diet

With our hands and forelimbs no longer needed for walking, they could now be redesigned to allow for other things, such as handling and throwing objects—which practices were surely helpful in allowing our ancestors to fend off other animals (not to mention other humans) out on the open plain (loc. 511-16). Now, our ancient arboreal ancestors were certainly vegetarians (loc. 582). However, it appears as though our species had made a move towards incorporating meat in their diet even before we branched off from the chimpanzees, for the chimps themselves consume a small amount of meat (about 3% of their overall diet). Nevertheless, given that these early humans were now in an environment where carrion had more of a presence—and given that they now had the potential to scavenge carcasses, as well as bring down animals with their new-found skills—there would have been selective pressure for them to evolve the capacity to add even more meat to their diet, which is precisely what occurred. As Wilson explains, “the Homo species… gathered and consumed vegetable food, but in addition they ate meat, most likely by sharing carcasses of larger prey brought down by other predators, as well as by catching smaller animals they could handle” (loc. 582). The shift to incorporate additional meat in our diet seems to have occurred roughly 2 to 3 million years ago (loc. 613).

With regards to our hunting skills, it is certain that they would have initially been rather meager—especially since we were no match for the speed of the vast majority of the animals on the plain. Nevertheless, given that we were already equipped with bigger, more complex brains than other animals, if we were to have had any advantage in hunting it would surely have been in the out-smarting department. Of particular significance here would have been the potential we would have had to cooperate with one another to bring down prey.

 3. The Evolution of Cooperation

Now, chimpanzees themselves show some restricted ability to cooperate to achieve goals—even in hunting (loc. 688-93). However, they appear to lack much of the mental machinery needed to achieve this in full (or, at least anywhere near to the degree that we do). The problem with evolving the ability to cooperate in a complex way is that it does not come cheap. That is, it requires a variety of mental tools and a great deal of brain capacity, which itself takes up a good deal of energy (indeed, our brains use up as much as 80% of our caloric intake). Fortunately, the recent shift that we had made to adding meat to our diet was able to supply the added calories needed to allow for this additional mental capacity to begin evolving (loc. 703, 788). As our brains grew bigger, and our hunting skills improved, we were able to obtain an ever increasing amount of meat, which allowed our brains to keep on evolving larger and larger (loc. 703).

As it turns out, servicing the needs of cooperation may not have been the only reason why our brains began to evolve to be larger. Indeed, many evolutionary biologists are convinced that the added adaptability that more intelligence brings would have been a big boon to a species that had recently entered a new and unfamiliar environment—as our species had done when our early ancestors gave up the trees for the savannah (loc. 642).

In any event, the capacity for sophisticated cooperation does not just require increased intelligence. Rather, it also requires a number of very specific mental abilities. These mental abilities include that of being able to pay close attention to the same object at the same time as others (loc. 3649); a high level of awareness and self-awareness (loc. 3649); and a recognition of the mental states of others, called ‘theory of mind’ (loc. 3649). In addition to these qualities, a number of emotions are needed to get complex cooperation up and running in earnest. Of particular importance here are the emotions that prompt us to help another in need, such as empathy and compassion (loc. 4004, 4031); the emotions that prompt us to return a favour received, such as guilt and shame (loc. 4010); and, crucially, the emotions that prompt us to punish cheaters, such as righteous anger, contempt, and disgust (loc. 4000, 4041-51). These last are particularly important since it is only when free-riders are sufficiently dissuaded from taking advantage of cooperative overtures (which punishments effectively achieve) that cooperation can flourish (for indeed, as powerful as guilt and shame sometimes are, they are evidently not always sufficient to ensure cooperation on their own).

The following is a documentary-style presentation of our early evolution (the second video is a continuation of the first), taking us from dextrous hands, to bipedalism, to cooperation, to tool-making, to art and religion (the latter three of which will be discussed in greater detail below). The full documentary from which these clips are taken (of which they are the 2^nd and 3^rd parts respectively) is called ‘The Journey of Life: Human Life’ and can be seen on Youtube (in 6 parts). The first part of the documentary introduces us to, and speaks more about the topics of bidpedalism and dextrous hands.

4. Warfare

The complex cooperation that the aforementioned traits allowed for not only helped humans in their early forays into hunting. Rather, they also helped them in a much more sinister endeavor: warfare. It is not that our newfound mental skills led us into warfare for the first time. Indeed, we have good reason to believe that this phenomenon had existed since well before the time frame in question (loc. 1295-1300). In fact, inter-group conflict and warfare appears to extend back even to the time before we branched off from the chimps, for modern chimpanzees also engage in it. As Wilson explains, “a series of researchers, starting with Jane Goodall, have documented the murders within chimpanzee groups and lethal raids conducted between groups” (loc. 1300). These inter-groups raids among chimps are often eerily similar to human practices (loc. 1304-18), as can be seen in the video below.

The main purpose of group raids among chimps is the usurpation of additional territory (loc. 1309-14), and this tradition appears to have carried over into our own species. Evidence indicates that our early ancestors lived in groups of between 30 to 100 members. According to Wilson, what likely happened is that when these groups grew too large (a phenomenon that would have occurred much quicker now than before, given the additional resource of meat [loc. 1345]) they would split into two or more groups. The splinter groups would “venture a few tens of miles settle, increase in numbers, then divide into two or more bands, capable of moving into new territory” (loc. 1449). As population continued to grow from the center of the living range, though, conflict would have been inevitable. Fortune would have favoured larger, more cohesive groups, since these two factors are the only ones that separate groups who are more or less equal in weaponry (loc. 898).

Groups whose members were naturally more cooperative would have had an advantage over groups whose members were less so, both in hunting and in warfare. Given that this is the case, Wilson argues that the more cohesive groups came to dominate and ultimately exterminate the others, thus allowing their more cooperative genes to dominate the gene pool, thereby shaping the evolution of our species. As Wilson puts it, “territorial behavior evolved as a device to sequester the food supply. Expansive wars and annexation resulted in enlarged territories and favored genes that prescribe group cohesion, networking, and the formation of alliances” (loc. 1350). Elsewhere, still more emphatically, Wilson writes that “only group selection, with groups containing more cooperators pitted against groups with fewer cooperators, will result in a shift at the level of the species toward greater and wider instinctive cooperation” (loc. 4000).

5. The Group-Level Selection Theory Controversy

Now, as it turns out, this is somewhat of a controversial position among evolutionary theorists. As Wilson himself points out, group-level selection has very much been out of favour in the scientific community for over 40 years. During this time, most in the field of evolutionary psychology (previously named sociobiology) and evolutionary biology have maintained that full-fledged non-kin cooperation came about through a combination of kin-selection and individual selection.

Specifically, the thought was that altruism (meaning genuine helping behaviour) first evolved to be directed towards close kin. It was allowed to evolve because, even though it may have cost the individual doing the helping, it served to benefit those who were also likely to carry the genes that were responsible for the helping behaviour to begin with (they being close kin of the original actor). From here, these altruistic sentiments evolved to extend to non-kin, since they allowed non-related individuals to reap the benefits of reciprocal altruism (wherein individuals swap favours and both come out ahead). Individuals who evolved this capacity out-competed those who didn’t, and thus the pull towards non-kin cooperation evolved at the level of individual selection.

At least, this is what was thought, and Wilson himself had been persuaded that this was correct (loc. 2759-79). However, based on a mounting trend of evidence, Wilson has now come to change his view, and here argues against this line of thought, contending that it falls apart under close scrutiny (loc. 2779-2838). In fact, this argument of the author’s is a major theme in the book, and therefore warrants some explanation.

For Wilson, the chief problem with the aforementioned line of thinking is with kin-selection. Specifically, it is Kin selection’s reliance on inclusive fitness that the author takes issue with. Inclusive fitness is the idea that your genetic fitness depends not just on how successful you are in surviving and reproducing, but how successful your kin are as well, since they have a higher likelihood of carrying your same genes as non-kin (the more closely they are related to you, the more likely they are of carrying your same genes) (loc. 2724-29).

With inclusive fitness at work, a behavior that costs an actor can still evolve if the net benefit to that person’s genes remains positive. This state of affairs can be captured by the following equation (first iterated by the biologist William D. Hamilton in 1964 [loc. 2734]): br > c. Here, b is the benefit that a behaviour contributes to an actor; r is the benefit that the behaviour contributes to that person’s close kin, and c is the cost to the original actor. According to this equation, a gene prescribing a particular behaviour will evolve if the benefit to the actor’s genes, multiplied by the benefit to that person’s genes elsewhere in the population, is greater than the cost to the actor (loc. 2734). To put this in concrete terms, using the example of altruism encountered above, “altruism will evolve if the benefit to a brother or sister is 2 times the cost to the altruist (r = ½) or 8 times to a first cousin (r = 1/8). To express this idea with a crude example,” Wilson continues, “you will promote the altruistic gene in you if you altruistically have no children, but if your sister more than doubles the number she has as a result of your altruism to her” (loc. 2739)—or if you perform a similarly altruistic act and your cousin happens to be the octomom (sorry, I couldn’t help that one : ).

Wilson’s complaint here has to do with the value represented by r, or the degree of relatedness that one person bares to another. What Wilson seems to be saying is that, while defining genetic relatedness may be possible at the level of the individual (say between siblings, or cousins), it is not possible at the level of the gene—where it truly must work, if the theory is to work. As Wilson explains the matter, “the original approach taken by inclusive-fitness theorists was to define r as pedigree relatedness, in other words how close members of a group are in the family tree. For example, siblings are closer than first cousins. This perfectly reasonable definition pins down the average numbers of genes shared by two individuals owing to common descent. It was soon recognized, however, that this definition of relatedness could not work for Hamilton’s equality in the majority of real and theoretical cases. As a result, different definitions were used at various times to satisfy the particular needs of the model being developed… In short, the only unifying theme seemed in time to be that r, originally defined by pedigree, is whatever it takes to make Hamilton’s inequality work. The inequality thereby lost meaning as a theoretical concept, and became all but useless as a tool for designing experiments or analyzing comparative data” (loc. 2831).

While kin-selection runs into these difficulties, Wilson contends that multi-level selection involving both individual and group-level selection does not. What’s more, the latter is able to account for the same phenomenon that kin-selection is designed to (loc. 2846, 2856). Given that this is the case, the author offers this rhetorical question to close the argument: “if there is a general theory that works for everything (multi-level natural selection) and a theory that works only for some cases (kin selection), and in the few cases where the latter works it agrees with the general theory of multi-level selection, why not simply stay with the general theory everywhere?” (loc. 2860).

In any event, whether non-kin cooperation is a matter of multi-level kin and individual selection, or multi-level individual and group selection, evolutionary psychologists and evolutionary biologists agree that it is a genetically evolved aspect of our species. (My own view is that kin-selection, individual selection and group selection are likely all involved here, as they are not mutually exclusive, and there are sound arguments behind all of them, but this is neither here nor there. Biologists and onlookers alike seem intent on dividing themselves on the issue, as is evident from the reviews of the book on the amazon.com site, shown in the following link: amazon reviews of ‘The Social Conquest of Earth’). With this established, then, let us move forward.

 6. The Controlled Use of Fire

We had reached a point in our evolutionary tale where humans were cooperating with one another both in hunting and in warfare, and where larger, more cohesive groups were out-competing and coming to dominate over the smaller and less cohesive. In the midst of this process, came the next major step in our evolution, which was the controlled use of fire.

Wildfires out on the open savannah of Africa are commonplace, and weaker animals are routinely caught up in their teeth, leaving an aftermath of scorched earth and barbecued delights. As Wilson explains, “the roving prehumans could not have failed to discover the importance of wildfires as a source of food. Moreover, they found some of the felled animals already cooked, with flesh easy to tear off and eat” (loc. 541).  The latter would have been a big boon to a species that had only relatively recently evolved to eat meat (and for whom complete digestion would still have been an issue), and the incentive to find a way to control fire for cooking purposes would have been strong.

The use of controlled fire was almost certainly originally adopted for the purposes of cooking. However, the effect of this new found ability would ultimately have much more important consequences for our way of life. This proves to be the case because, as Wilson has it, the practice of building campfires led directly to our early ancestors establishing more permanent and central homes, as they gathered around a common hearth (loc. 534-54). This important shift appears to have occurred about a million years ago (loc. 554).

7. Eusociality

For Wilson, our gathering around a campfire at a communal campsite was particularly important because it was the first step towards our becoming the truly eusocial species that we are today (eusocial literally means ‘true social condition’ [loc. 1856]). Eusocial species are characterized by a few integral features. As the author explains it, “members of a eusocial animal group, such as a colony of ants, belong to multiple generations. They divide labor in what outwardly at least appears to be an altruistic manner. Some take labor roles that shorten their life spans or reduce the number of their personal offspring, or both. Their sacrifice allows others who fill reproductive roles to live longer and produce proportionately more offspring” (loc. 1860).

Very few species are fully eusocial. Many will be aware that bees, wasps, ants and termites are. Beyond these, only a small handful of species of beetles, aphids, thrips, shrimps, and mole rats (in addition to ourselves) may be considered fully eusocial (loc. 2235, 2244) (a few species have come close, such as certain species of helper-at-the-nest birds, and some canids, but they ultimately fall just short [loc. 2245]).

The fact that there are so few eusocial species is somewhat strange, since those who are are some of the most successful species on the planet. Indeed, as Wilson explains, “the twenty thousand known species of eusocial insects, mostly ants, bees, wasps, and termites, account for only 2 percent of the approximately one million known species of insects. Yet this tiny minority of species dominate the rest of the insects in their numbers, their weight, and their impact on the environment… Among creatures larger than microorganisms and roundworms, eusocial insects are the little things that run the territorial world” (loc. 1875).

Wilson actually devotes a fair bit of space in the book to the eusocial insects and their evolution. He does this both to account for how these insects have come to be as successful as they are (the social conquest of earth includes not just our species after all, but these incredible insects as well), and also to provide us with a better understanding of our own evolution, and how and why we are both similar to and different from these insects. Due to space constraints though—as well as the fact that this story takes us somewhat away from the story of our own evolution—I will not pursue it here. Nevertheless, it should be mentioned just how remarkable, and how remarkably complex some of these species are. Ants in particular deserve special recognition here, and many will be aware that they have achieved such feats as a complex division of labour, agriculture, herding, and even medicine. These feats are outlined in the two videos below.

Among vertebrates, only ourselves and the naked mole rats are eusocial, and the success of our species in terms of population, geographic spread, and impact on the environment goes without saying. (In fact, it is Wilson’s belief that the impact that our species has had on the environment has been more than a little over-reaching, as he is wont to point on several occasions over the course of the book. Here is one such example: “we are an evolutionary chimera, living on intelligence steered by the demands of animal instinct. This is the reason we are mindlessly dismantling the biosphere and, with it, our own prospects for existence” [loc. 240]). The author sums things up thus: “as the eusocial insects are to the far vaster world of invertebrate animals… [so] humans are to the world of vertebrate animals” (loc. 1880).

Given that many of the eusocial species have been so successful, the question becomes, then, why so few species have become eusocial. For Wilson, the answer to this question has two parts. To begin with, the author argues that crossing the threshold to eusociality requires a host of preadaptations which are themselves fairly rare in nature (loc. 2555). The first and most important of these preadaptations is the inhabitation of a nest in which the members of the group raise their young, and near which they forage for food: “all animal species that have achieved eusociality, without exception, at first built nests that they defended from enemies. They, as did their known antecedents, raised young in the nest, foraged away from it for food, and brought the bounty back to share with others” (loc. 559).

8. Human Campsites/Nests

And this brings us back to where we started before our little digression into eusociality: human campsites. Specifically, campsites with fires. As mentioned above, Wilson maintains that it was the controlled use of fire which first led early humans to establish more permanent and centralized home-bases, or ‘nests’. And this became the first step in our becoming a true eusocial species.

Why is this step so important? First of all, nests bring group members together into a very tight social community (loc. 725). Also, nests must be protected, which means that all of the group members are necessarily invested in a common goal. What’s more, the defense of the nest is a necessary and persistent requirement, and therefore, a division of labour must occur: “some forage and hunt, others guard the campsite and young” (loc. 744, 811). Of equal importance, the group members must share the resources that they obtain, and “in ways that are acceptable to all” (loc. 742). In short, the group must act as a single whole, a unit, a kind of superorganism (loc. 2182). Given that this is the case, the selection pressure for more cooperative, more cohesive group members intensifies even further. This selection pressure (which, according to Wilson, operated at both the individual and group level [loc. 883-906]), is, for him, the key to understanding the final stages of our evolution as a species (loc. 757), to which we will now turn.

PART II: THE BIOLOGICAL EVOLUTION OF CULTURE:

THE ORIGINS OF TRIBALISM, LANGUAGE, RELIGION AND ART

9. The Evolution of Tribalism

To begin with, Wilson contends that the added selection pressure towards cooperation and cohesion not only intensified our pre-existing cooperative sentiments, it also began cultivating a deep seated tribalism, or in-group orientation, in our species. This tribalism can be seen today in our affinity for joining, and of feeling a part of groups of all sorts from religious organizations to sports teams: “the social world of each modern human is not a single tribe, but rather a system of interlocking tribes, among which it is often difficult to find single compass. People savor the company of like-minded friends, and they yearn to be in one of the best—a combat marine regiment, perhaps, an elite college, the executive committee of a company, a religious sect, a fraternity, a garden club—any collectivity that can be compared favorably with other, competing groups of the same category” (loc. 979). Our love of groups extends even so far as wanting to be a part of them remotely, as with fans of modern sports teams—whose actions and behaviours often betray the fact their affiliation with their favourite team is only from afar (loc. 979-97).

This tribalism of ours consists not only in a desire to be a part of social groups, and a feeling of loyalty towards the members of the groups of which we are a part, but a corresponding mistrust and contempt for members of out-groups: “experiments conducted over many years by social psychologists have revealed how swiftly and decisively people divide into groups, and then discriminate in favor of the one to which they belong” (loc. 997). And this discrimination emerges even when the groups are created arbitrarily, and artificially in the lab: “Even when the experimenters created the groups arbitrarily, then labeled them so the members could identify themselves, and even when the interactions prescribed were trivial, prejudice quickly established itself. Whether groups played for pennies or identified themselves groupishly as preferring some abstract painter to another, the participants always ranked the out-group below the in-group. They judged their ‘opponents’ to be less likable, less fair, less trustworthy, less competent. The prejudices asserted themselves even when the subjects were told the in-groups and out-groups had been chosen arbitrarily” (loc. 1002).

While some have contended that this tribalism of ours is a learned trait, it appears that the only thing learned about it is precisely which groups to be loyal to (your own, of course) and which to despise (any of which you are not apart, and particularly those that oppose you in any way) (loc. 1006). Indeed, there is now a good deal of evidence that our groupishness is a deeply ingrained aspect of our nature. This evidence includes not only the power and universality with which we feel the pull towards groups (loc. 1006, 1015-30), but the fact that it is present in us from a very early age—indeed even from infancy (loc 1010-1015).  What’s more, it makes perfect sense that tribalism would have evolved in our species, since, as Wilson points out, it would have provided that added bit of cohesion that would have been invaluable in our tussles with other groups.

While this tribalism of ours would appear to have a very ancient origin, it was not until much later, according to Wilson, that its full impact would be felt; for it would later prove integral in our species’ adoption of organized religions (a topic that will be touched upon in more detail below).

10. The Divided Psyche: Virtue and Vice

For Wilson, the evolution of our cooperative and tribalist sentiments goes a long way in explaining why we have an altruistic, selfless dimension to our psyches, and hence why our psychology is torn between vice on the one hand (or shoulder), and virtue on the other. Specifically, the contention is that the force of individual selection pulled us towards selfishness, while the force of group selection pulled us towards altruism and selflessness, and we live with a divided psyche as a result. As Wilson explains the matter, “the dilemma of good and evil was created by multi-level selection, in which individual selection and group selection act together on the same individual but largely in opposition to each other. Individual selection is the result of competition for survival and reproduction among members of the same group. It shapes instincts in each member that are fundamentally selfish with reference to other members. In contrast, group selection consists of competition between societies, through both direct conflict and differential competence in exploiting the environment. Group selection shapes instincts that tend to make individuals altruistic towards one another (but not toward members of other groups)” (loc. 3890). This last point is important, of course, for it reveals that group selection has not exclusively been a force for cooperation and cohesion, as it is also behind much of the discrimination and racism that we continue to see to this day.

11. The Evolution of Language

In the next stage of our evolution, language enters the scene. It was once thought that language may have been purely a matter of cultural invention. However, it is now understand that there is most definitely a biological backing to this capacity of ours. Indeed, given the ease with which we use language, and the readiness and eagerness with which we learn it as youngsters, it is quite clear that we picked up language in the course of our genetic evolution (loc. 3746-49). Beyond this, there is a good deal of evidence in neuroscience (as well as anatomy) to suggest that we are in fact prewired for language.

So, how did language evolve? According to Wilson, language evolved by way of borrowing from the very mental capacities that had earlier allowed for sophisticated cooperation. As you will recall, human cooperation requires three very important mental abilities. Wilson describes them thus: “shared intention—in other words, the tendency to pay attention to the same object at ongoing events as others… A high level… of awareness… needed to act together in achieving a common goal (or thwarting others in the attempt). And… a ‘theory of mind,’ the recognition that [one’s] own mental states would be shared by others” (loc. 3645).

For Wilson, these are the exact abilities that are also needed to allow for language (loc. 3651). All that is needed over and above them is the added capacity to think in the abstract, and to appreciate that any entity may represent, or symbolize any other: “the sequence in cognitive evolution was from intense social interaction in early settlements to a synergism with increasing ability to read and act upon intention, to a capacity to create abstraction in dealing with others and the outside world and, finally, to language” (loc. 3660). According to Wilson, the evolution of language most likely took place between 70,000 and 160,000 years ago (loc. 1530, 3517), based on the evidence of the sophistication of the artifacts found at this time. Incidentally, this is also right around the time when our species left Africa and began spreading across the planet. The approximate timeline of this migration is outlined in the following image:

And why did language evolve? Well, we can well see how the ability to communicate complex messages would have been a great boon to a highly cooperative species (loc. 3655); and in this sense the evolution of language would have been a natural next step—especially given the preadaptive mental abilities that our ancestors had already evolved to that point.

12. The Evolution of Culture

Once language was on the scene we were ready for the next stage of our evolution, which was a massive blossoming in our capacity for culture. Borrowing the broad definition of culture used by both anthropologists and biologists, Wilson outlines culture as “the combination of traits that distinguishes one group from another. A culture trait is a behavior that is either first invented within a group or else learned from another group, then transmitted among members of the group” (loc. 3438). Although language gave an enormous boost to our capacity for culture, it is not the case that language was needed to make culture possible in the first place. Indeed, culture predates the arrival of language. This is certainly true since even other animals, including, most notably, our closest evolutionary ancestor (the chimpanzee) display cultural behaviour (loc. 3444-57).

Of course, our own species has taken culture to a whole other level, but even before its enormous blossoming as a result of language, our species showed signs of an increasingly complex culture. The evidence of this begins with the advancements in stone tools that started about 1.5 million years ago (loc. 1384, 1419-26). As impressive as these early advancements in stone tools are, though, they are a far cry from what we commonly think of as culture, with its art, dance, music, cuisine, dress and religion. And indeed, these expressions of culture only became possible with the advent of language (we will return to this theme below).

Interestingly, the capacity for culture is actually the result of a biological adaptation. Specifically, the adaptation of being able to build new scenarios imaginatively out of a store of long term memories (loc. 3479, 3586). And what might have driven the selection for this trait? According to Wilson, it is the product of group-level selection: “there was undoubtedly competition among group members, leading to natural selection of traits that gave advantage of one individual over another. But more important for a species entering new environments and competing with powerful rivals were unity and cooperation within the group. Morality, conformity, religious fervor, and fighting ability combined with imagination and memory to produce the winner” (loc. 3591).

Now, it was once popularly thought that the advent of culture opened behaviour up to an unrestricted realm of possibilities, and that its onset effectively eliminated genetic influences on our behaviour, and ultimately ended genetic evolution as a force operating on our species. However, all of this has now very much been rejected. To begin with, while cultural innovation and learning allows for new responses to the environment, there is no reason to believe that these responses are not influenced to some degree at the genetic level. In some cases the genetic influence will be very rigid, such as in the case of the near universal taboo on incest (loc. 3820). While in other cases, the genetic influence will be very plastic, allowing itself to be manifested in a wide variety of ways. For instance, “the general practice of fashion in dress, ranging from loin cloth to white tie, has a genetic basis. However, because of the extreme (yet far from infinite) plasticity in the prescribing genes, and the multiple emotions they variously express, individuals select from several up to hundreds of options during their lifetimes” (loc. 3815).

The degree of plasticity in the expression of genes is itself subject to the forces of natural selection (loc. 3819). It all depends on whether the environment in which we evolved favored a rigid response, or one that could be modified based on different environmental inputs. For example, “when a rule is absolute, such as destruction by incest, there is only one hand to play; in this case, it is labeled ‘outbreed’. When a part of the environment is unpredictable, on the other hand, the person is wise to use a mixed strategy achieved by plasticity. If one trait or response does not work, switch to another within the genetic repertory” (loc. 3828). In these latter cases, additional plasticity was adaptive, and so was allowed to evolve. The finite plasticity with which the genes that are behind our cultural behaviour are endowed, is responsible for both the presence of cultural universals, as well as the fact that these cultural universals are expressed in different ways across different cultures.

Now, it may seem that once the capacity for culture had come on the scene that genetic evolution would cease to operate on our species, for “why, it is… reasonable to ask, be ruled by genes if cultural changes could achieve the same result in such short order” (loc. 3180). According to Wilson, it is the case that cultural evolution has a dampening effect on genetic evolution (loc. 3185). However, it is not the case that it extinguishes it entirely, for there remain situations when genetic adaptations prove to be more successful than cultural ones: “cultural evolution undoubtedly does tend to smother genetic evolution. Even so, there are novel challenges and opportunities abounding in the world’s many habitats that can also be met—or at least met more effectively—by a change in genes guided by natural selection, including strange new foods, diseases, and climatic regimes” (loc. 3185).

13. Gene-Culture Co-Evolution

So genetic evolution has continued to operate on our species even after the advent of culture, and cultural evolution. Aside from these though, yet another form of evolution has come to operate on our species: gene-culture co-evolution. This occurs when cultural innovations change the environment to such a degree and in such a way that selection pressure favors genetic modification. The most familiar example here is that of lactose tolerance. Up until 9,000 years ago, our ability to digest lactose ended with infancy. However, “when herding was developed 9,000 to 3,000 years ago, variously and independently in northern Europe and East Africa, mutations spread… that sustained lactase production into adult life, allowing the continued consumption of milk. The advantage to survival and reproduction in utilizing milk and milk products proved enormous” (loc. 3193).

And the examples of gene-culture co-evolution do not end here. Indeed, as Wilson points out, “over the past half century, large numbers of other such intertwined coevolutionary processes have been uncovered by anthropologists and psychologists” (loc. 3198). What’s more, for Wilson, gene-culture co-evolution explains a large part of the behaviour that we intuitively think of as being quintessentially human (loc. 3203), such as the visual arts, music, dance and religion, and we will now turn our attention to these—beginning with the latter first.

14. The Origins of Religion

For Wilson, once our cooperative and tribalist sentiments were on the scene, language had arrived, and (as a result of this) the capacity for culture had exploded, the stage was set for the arrival of religion and the arts. Evidence of early religion exists beginning approximately 100,000 years ago, with the presence of burial sites (loc. 4496-4502). These burial sites, Wilson explains—with their careful arrangement of the body, and the addition of ceremonial objects (such as deer antlers)—“suggests not just an abstract awareness of death but also some form of existential anxiety” (loc. 4502).

For Wilson, the pull to religion likely began when human beings started asking the uncomfortable question “where do all these dead people go?” (loc. 4283). The answer to this question, the author argues, would have been intuitively clear to these early humans: the spirit world that exists in dreams. The dead in question certainly turned up in their relations’ dreams, as they continue to do for us today. What’s more, they would have also turned up in their hallucinogenic reveries. Indeed, the practice of using hallucinogens to access the spirit world is still prevalent among hunter gatherer tribes today (loc. 4217-40), and we have good reason to believe that the practice extends back to when humans first became fully self aware, or shortly thereafter.

The spirit world, of course, contains not just the just the dead, but all manner of “allies, gods, angels, demons, and monsters” (loc. 4285). In time, the job of interpreting the visions encountered in dreams and hallucinogenic episodes came to be turned over to a specialist, today know as a shaman (loc. 4293), who no doubt interpreted the dreams and visions in a way that served the interests of the tribe and its continuing cohesion.

The spirit world would also have been the natural place to look for answers to the other questions that our early ancestors would have had—questions such as ‘What are we?’, and ‘Where did we come from?’. In order to answer these and other conundrums the spirit world would have been plumbed for the creation stories that could appease our searching and anxious minds: “the creation myths explain all they need to know of deep history in order to maintain tribal unity. In times of change and danger, their personal faith promises stability and peace. When faced by threat and competition from outside groups, the myths assure the believers that they are paramount in the sight of God” (loc. 4308).

Once religion was used to answer the existential questions that the group members had, it became a rallying point for the group itself, and the focus of their tribalist sentiments. As Wilson explains it, “acceptance of the bizarre creation myths binds the members together” (loc. 4192). In a sense, then, religion played directly into the hands of the pre-existing tribalist predisposition of our psyches, and fulfilled this tribalist predisposition to perfection: “the evidence that lies before us in great abundance points to organized religion as an expression of tribalism. Every religion teaches its adherents that they are a special fellowship and that their creation story, moral precepts, and privilege from divine power are superior to those claimed in other religions… the power of organized religion is based upon their contribution to social order and personal security, not to the search for the truth. The goal of religions is submission to the will and common good of the tribe” (loc. 4182-92).

15. The Origins of Visual Art, Music & Dance

Not long after the first burial sites turned up, artistic expression enters the scene. The first evidence of human art exists in the form of pierced snail shell necklaces and the use of red ochre some 80,000 years ago (loc. 4499). The timeline here make sense according to Wilson, since, for him, both religion and art would only have became possible with the advent of abstract and symbolic thought, which had just earlier allowed for language: “the creative arts became possible as an evolutionary advance when humans developed the capacity for abstract thought. The human mind could then form a template of a shape, or a kind of object, or an action, and pass a concrete representation of the conception to another mind. Thus was first born true, productive language, constructed from arbitrary words and symbols. Language was followed by visual art, music, dance, and the ceremonies and rituals of religion” (loc. 4486).

Around 35,000 years ago a true creative explosion occurred, as is reflected in the cave art of southwestern Europe. As Wilson points out, “from this time on until the Late Paleolithic period over 20,000 years later, cave art flourished. Thousands of figures, mostly of large game animals have been found in more than two hundred caves distributed through southwestern France and northeastern Spain, on both side of the Pyrenees. Along with Cliffside drawings in other parts of the world, they present a stunning snapshot of life just before the dawn of civilization” (loc. 4507).

The filmmaker Werner Herzog has recently been given unprecedented access to the caves and has produced a truly remarkable documentary about the experience. If you have not yet seen it, I highly recommend it. In the meantime, here is a short clip (not from Herzog’s film) giving us access to a few of the caves’ delights (short clips of Herzog’s film are available on Youtube):

As for the purpose of the cave art, this remains uncertain. Wilson speculates that some of the art was no doubt drawn to depict ordinary life, but adds that at least some of it was also likely to have had ritual importance, perhaps “to conjure sympathetic magic and increase the success of hunters in the field” (loc. 4526). The evidence for there being some element of magic in the art includes the fact that one painting depicts “what is most likely a shaman with a deer headdress, or possibly a real deer’s head. Also preserved are sculptures of three ‘lion-men,’ with human bodies and the heads of lions” (loc. 4531).

Lending credence to the idea that this early art had some ritual function is the fact that the first musical instruments also crop up around 30,000 years ago, and in the same vicinity as the cave art (loc. 4544-49). The first musical instruments consisted in rudimentary flutes, and may have included other types of instruments as well (such as chimes), though the authenticity of many of the artifacts thought to be instruments remains uncertain (loc. 4553).

When it comes to our capacity and affinity for music, there is good evidence to believe that it may actually be a product of biological, and not just cultural, evolution. This idea is based on the fact that music, often accompanied by dancing, is universal (loc. 4560), as well as the fact that there are deep similarities in the forms that it takes across cultures (loc. 4560-65). Also, it is clear that music is deeply ingrained in us, as it triggers strong emotions, and, as Wilson explains, is “extraordinarily complex in the neural circuits it employs, appearing to elicit emotion in at least six different brain mechanisms” (loc. 4584). In addition, it would make sense that music is biologically evolved, since it serves several adaptive purposes: “It is self-evident that the songs and dances of contemporary hunter-gatherer peoples serve them at both the individual and the group levels. They draw the tribal members together, creating a common knowledge and purpose. They excite passion for action. They are mnemonic, stirring and adding to the memory of information that serves the tribal purpose. Not least, knowledge of the songs and dances gives power to those within the tribe who know them best” (loc. 4574).

In terms of brain wiring and development, music is closely related to language in several ways, including syntactically, and in patterns of melodic ups and downs (loc. 4585-93). Given that this is the case, Wilson concludes that “it is tempting to think that the neural processing of language served as a preadaptation to music, and that once music originated it proved sufficiently advantageous to acquire its own genetic predisposition” (loc. 4599).

PART III: EARLY CULTURAL EVOLUTION:

FROM THE BEGINNINGS OF AGRICULTURE TO THE RISE OF CIVILIZATIONS

16. Early Agriculture

One of the major themes in culture is technology of course, and the advent of language certainly seems to have sped up technological progress (in addition to the other aspects of culture that it also pushed forward). The single biggest technological innovation in our species’ history is without a doubt the invention (or discovery) of agriculture. How did agriculture first arise?

Fires, and especially ground fires, have a peculiar effect on the environments that they ravage. In particular, they are “followed in savannas and dry forest by the growth of increased amounts of fresh, edible vegetation. Nutritious underground tubers are for a while also easier to find and excavate” (loc. 1652). Now, by about 45,000 years ago, our ancestors were already using controlled fires to drive and capture game (loc. 1647). According to Wilson, these people must have recognized the additional bounty that was left following the fires, and soon enough began exploiting this effect to their benefit (loc. 1652). The practice of slashing forest and burning it for the purposes of agriculture is one that remains common today among hunter-gatherer horticulturalists and straight ahead horticulturalists.

An abundance of plant-based food is particularly important because it allows for a great deal of population growth and a more settled lifestyle. Given the advantage of group size when it comes to inter-group competition, the benefits of agriculture could not have been ignored. Those groups who failed to adopt agriculture themselves would have been overrun by those who had (loc. 1617).

17. Advanced Agriculture, Chiefdoms & The Explosion of Culture

The true planting of seeds and cultivation of crops began some 10,000 years ago (a period known as the Neolithic revolution), and in fact was invented independently in several locations across the planet (8, it is now thought [loc. 1627]). At around this time, and perhaps even a little before, “domestication was practiced on animals captured in the wild and converted into pets and livestock” (loc. 1659).

The invention of true agriculture and the domestication of animals allowed for an additional explosion in population, as well as huge food surpluses. Villages naturally formed (loc. 1516). Both the larger populations, and the food surpluses required management by leaders, and eager individuals stepped in to fulfill the role (called chiefs, or ‘big men’).

Chiefs did not rule by outright coercion, but by political means. As Wilson describes them, “chiefs or ‘big men’ rule by prestige, largesse, the support of elite members below them—and retribution against those who oppose them. They live on the surplus accumulated by the tribe, employing it to tighten control upon the tribe, to regulate trade, and to wage war with neighbors” (loc. 1721).

Successful chiefs would naturally attempt to extend their influence as far as they were able. However, the territory over which they could rule was limited to that which they could walk to in a single day from their home village. In practice, this meant that their domains were restricted to “a maximum of twenty-five to thirty miles” (loc. 1724).

With the arrival of agriculture and the system of chiefdoms that arose out of it, cultural innovation exploded and spread further and faster than ever. This was allowed to occur because new inventions were increasingly spread through trade and war, and each new invention made an increasing number of even newer ones possible, as innovation built upon innovation (loc. 1614-23).

18. The Rise of Civilization: The First States

In order to overcome the limitation in the range of their domains, successful chiefs added layers of hierarchy to their political bodies, conquering lands further and further away from their home villages, and then delegating authority over these holdings to subordinate officials. This led to the rise of the first true states: “States, the final step up the cultural evolution of societies, have a centralized authority. Rulers exercise their authority in and around the capital, but also over villages, provinces, and other subordinate domains beyond the distance of a day’s walk, hence beyond immediate communication with the rulers. The domain is too far-flung, the social order and communication system holding it together too complex, for any one person to monitor and control. Local power is therefore delegated to viceroys, princes, governors, and other-chief-like rulers of the second rank. The state is also bureaucratic. Responsibility is divided among specialists, including soldiers, builders, clerks and priests” (loc. 1729).

As wealth accumulates, and additional specialization develops, “the public services of art, sciences, and education can be added—first for the benefit of the elite and then, trickling down, for the general public” (loc. 1729).

The rise of civilizations also brought about a shift in the area of religion. Indeed, as societies grew in size, and became ever more hierarchical—with a single king positioned above the throngs below him—the view of the gods echoed this transformation: “People… project their humanness into animals, machines, places, and even fictional beings. It has been relatively easy in such transference to take the step from human rulers to invisible divine beings. For example, God in all three of the Abrahamic religions (Judaism, Christianity, and Islam) is a patriarch much like those in the desert kingdoms in which these religions arose” (loc. 4206). Also, as societies grew, group cohesion became increasingly illusive, and so the gods (or one God) took on the added responsibility of ensuring this cohesion (loc. 4298). With these changes in hand, our modern religions took shape, and they remain with us in this form to this day.

Thus ends the story of the genetic and cultural evolution of humankind up to the conclusion of prehistory, and the beginning of history (Wilson does not bother to continue his account up through history itself, as this is very much a separate story).

19. Conclusion

The author closes the book with a recap of the major steps that brought us to our present condition, as well as a brief prognostication about the future of our species. Here we are reminded of how we are destroying the biosphere in which we live (loc. 4727). Wilson himself predicts that we will continue do so well into the future, but that eventually we will learn from our mistakes. The author ends his book with this bitter sweet prediction: “Earth, by the twenty-second century, can be turned, if we so wish, into a permanent paradise for human beings, or at least the strong beginnings of one. We will do a lot more damage to ourselves and the rest of life along the way, but out of an ethic of simple decency to one another, the unrelenting application of reason, and acceptance of what we truly are, our dreams will finally come home to stay” (loc. 4779).

*Thank you for taking the time to read this article. If you have enjoyed this summary of E.O. Wilson’s ‘The Social Conquest of Earth’, or just have a thought, please free to leave a comment below. Also, if you feel others may benefit from this article, please feel free to click on the g+1 symbol below, or share it on one of the umpteen social networking sites hidden beneath the ‘share’ button.

Cheers,

Aaron,

The Book Reporter