Lone Survivors (19 page)

There is evidence that pair-bonded birds and mammals have relatively larger neocortices, and one possibility is that in higher primates, and particularly in humans, the social and thinking skills used in pair-bonded relationships have been extended many times over for creating and maintaining relationships between individuals who are not partners in reproductive terms. Thus individuals of the same or opposite sex may form bonds as intense and long-lasting as those normally found between pair-bonded mates in other species; in other words, humans have mates beyond just sexual mates. For this to work successfully and in the long term, it requires the extension of high-level social skills of trust, empathy, and synchronization of actions beyond the immediate “family group” and into the larger social community. These links would be valuable in terms of reliable support in times of difficulty, and through an extended web of such relationships crosscutting through the whole group, all could benefit from coordinated action, food sharing, protection from predators, et cetera.

Thus many scientists believe that our substantial brains evolved via selection for life in large groups, and this led to the development of deep social minds in primates, with the ability to “mind-read” (observe and interpret the actions of) others in the group, to learn and pass on “cultural” behavior within the group, and to cooperate not only for mutual benefit but for the benefit of others in the group. Mind reading, or possessing a “theory of mind” about oneself and others, can occur at several levels and for many different social purposes, for example, interpreting what individual A thinks about individual B and then behaving so as to manipulate the behavior of A toward B. (This social “skill” is sometimes known as
Machiavellian intelligence
, a term introduced by Byrne and Whiten, after the Florentine political philosopher Niccolò Machiavelli.)

Mammals and birds seem to have a first order of intentionality, that is, they are aware of their own behavior and its possible impact on others; as mentioned, some of this may be related to the demands of strong pair-bonding or living in herds or flocks. But by the age of four, human children can operate at two levels of intentionality in their social perceptions, that is, perceiving and interpreting not only their own behaviors but also the behaviors of those immediately around them. Thus children have the ability to recognize that others may have the same, or different, perceptions of the world compared with their own. At this stage such recognition means that they can begin to manipulate, or try to manipulate, those around them, whether these are parents, siblings, their peers, or their nursery school teachers. There is evidence that chimpanzees approach the same level as four-year-old children in their theory of mind, but they never move beyond this, whereas most humans develop further to cope with several higher levels of intentionality. Robin Dunbar illustrated this point with reference to Shakespeare's play
Othello,
where the playwright had to simultaneously handle four mind-states on the stage: Iago intends that Othello should believe that Desdemona loves Cassio and Cassio loves her. But Shakespeare moved beyond that because, to be successful, he also had to be able to visualize the audience's reaction to what he was writing—and so he was working to at least a fifth-order intentionality, right at the limits of human mind-reading abilities. These highest levels, supporters of the SBH argue, are unique to modern humans, and they evolved through the need for our ancestors to map the growing complexities of their social relationships. This in turn raises the question of why such complexities had developed.

SBH perhaps helps to explain something that does differentiate most human hunter-gatherer groups both from our primate relatives and from modern industrialized societies: egalitarianism. Hunter-gatherers usually have little in the way of owned material possessions, since they are difficult to maintain and transport with a nomadic lifestyle, and this social equality is reflected in things like food sharing, lack of formal leadership, and the prevalence of monogamous relationships. This last contrasts with the polygamy that characterizes primates such as baboons and gorillas, as well as many agricultural and pastoralist societies, where a few men may accrue disproportionate wealth, status—and wives. Maintaining social equality often requires positive coordinated efforts by the group to resist those individuals who try to assert excessive dominance. Coordination of activities extends to bands of women who plan ahead to go foraging for plant foods, insects, and small game, and to hunting bands, who must also plan ahead, communicate about tracks and signs, and adopt specific roles in catching and processing prey. In terms of the vital activity of food acquisition, the degree of coordination that a sophisticated social brain can help to deliver means that the group acts more like a food-gathering machine than the host of individual and “selfish” foragers typical of a monkey or ape troop.

But there are real practical limits on the size of a group that can successfully interact and function at a personal level, and this has been enshrined as
Dunbar's number
, following Robin Dunbar's research. In primates this may be the subgroup in a troop who regularly interact by means such as mutual grooming of fur, and can range up to about sixty. For Dunbar, what ultimately limits the size of such groups in different primates is the relative size of the neocortex, which governs how many friendly relationships or meaningful acquaintances can be successfully managed at any one time (although recent research suggests that the small regions known as the amygdala, located near the base of the brain, also play an important role in humans). Dunbar's number in modern humans seems to fall between about 100 and 220 (average 148), and the figure matches quite well with the optimum size of large hunter-gatherer aggregations, tribal villages, Hutterite settlements, small military units, and even the average number of people in effective social networks on the Web. As we shall see later in this chapter and the next, the relatively large size of human aggregations has had consequences in terms of the need to develop new means of communication (symbolism and language) and the evolution of more complex social structures and fully human culture.

With our large brains, evolved for and geared to interact flexibly with a network of people in our social group, we can exchange information of mutual benefit. But how free are we really in these interactions, and how important is our genetic inheritance in determining what we can and cannot do? In chapter 7 I will discuss our DNA and genes, and their importance in reconstructing the processes of human evolution, but there is no doubt that our DNA does provide a basic template for our behavior. It's a template that provides both limiting and varying factors in what we can and cannot do (for example, in determining the basic size and shape of our brain, the extent of human dexterity, running speed, acuity of vision and hearing). At the same time, it is obvious that humans can improve elements of performance through learning and practice, and many of these are influenced by differences in both the physical and social environments (for example, diet, health, upbringing, and social norms). So our DNA is more like a flexible container than a mold in the way it determines and sets limits on how we behave. Nevertheless, as we shall see, some scientists believe not only that the structure of the modern human brain is quantitatively different from that of earlier humans in its size and the extent of its gray matter, but that genetic changes unique to modern humans also qualitatively rewired our brains about 50,000 years ago, making us behaviorally modern at a stroke. If that was so, then despite their large brains, Neanderthals were fundamentally unlike us in their lack of human behavior, because they followed a separate evolutionary trajectory. That same lack would have applied to the modern humans who occupied Africa before 50,000 years ago, because they lived before the mutations occurred that made us fully modern.

How much of our modern behavior was shared by earlier human species? That is a very difficult question to address, let alone answer, from the data we have. Some researchers produced a sort of checklist of modern behavior, which, it is argued, characterizes humans today and which can then be used to examine the archaeological record for when and where those traits first appeared. Other workers would dispute their usefulness, their universality, and how accurately they can be inferred from the imperfect materials that survive in the ground from ancient times. But the list of behaviors often includes: complex tools, the styles of which may change rapidly through time and space; formal artifacts shaped from bone, ivory, antler, shell, and similar materials; art, including abstract and figurative symbols; structures such as tents or huts for living or working that are organized for different activities (such as toolmaking, food preparation, sleeping, and for hearths); long-distance transport of valued materials such as stone, shells, beads, amber; ceremonies or rituals, which may include art, structures, or complex treatment of the dead; increased cultural “buffering” to adapt to more extreme environments such as deserts or cold steppes; greater complexity of food-gathering and food-processing procedures, such as the use of nets, traps, fishing gear, and complex cooking; and higher population densities approaching those of modern hunter-gatherers.

In the last fifteen years there have been some remarkable discoveries that emphasize the complexity of early modern human behavior in Europe and elsewhere. Can any of these provide clues as to what triggered the changes that led to our modern minds and patterns of behavior? To understand this, we need to address the important question of symbolism, which many people think is a key to understanding what made us different from any creatures that came before us. We use symbols in so many ways today that they are a part of our lives, taken for granted, but without which we could hardly function. They may be pictorial, such as a drawing which, though small, black, and two-dimensional, resembles the larger solid object it represents—say, a picture of a stick-man or stick-woman, or a plane. Or it could be a written word, which does not resemble at all the object or action that it stands for—like the word
computer
. Or perhaps it could be a series of musical notes, which can only transform into sounds when interpreted through the eyes, brain, and actions of a musician. Symbols may equally represent social signals about group identity, wealth, or status; here I don't just mean bundles of banknotes, which are, of course, merely pieces of paper with some printing on them. Equally symbolic are fashions in clothing, hairstyles, cosmetics, tattoos, and necklaces, which are used to send signals about the wearer to other individuals in the group.

Symbols are meant to transmit messages and usually require the recipient to be able to interpret them in the same terms as they were originally intended, although they can, of course, equally be used to exclude those who cannot receive and interpret them—a secret code or a ritual handshake, for example, the meaning of which is known only to members of a privileged group. The archaeologist Clive Gamble, following the primatologist Lars Rodseth, emphasized that one of the most distinct things about modern humans compared with our primate relatives is our “release from proximity.” Probably all humans before us, like the apes they evolved from, could only work through face-to-face encounters, but with the rise of symbolism (and the associated development of language), people were liberated from proximity and could communicate through time and space. Thus a message with social meaning could be transmitted remotely on behalf of a person or group, provided the recipients could decode it in the same terms.

About twenty-five years ago, the concept of a 35,000-year-old Human Revolution emerged. This revolution considerably preceded, but matched in significance, other transformations such as the domestication of plants and animals, the discovery of metalworking, and the development of industrialization. This revolution seemed to be associated with the arrival of the modern-looking Cro-Magnons in Europe; they had imported or rapidly developed a package of modern human behaviors, such as complex language, art, and specialized technologies, enabling them to replace the behaviorally inferior Neanderthals. In 1987 I was fortunate to co-organize an influential conference in Cambridge that became known as the “Human Revolution” meeting, where this view really took off. Many have since criticized the Eurocentric focus of those debates about the origins of symbolism and modernity. Certainly the European evidence for early symbolism still dominates the Paleolithic record, not only because of the large number of accessible sites that preserve the finds, but also because of the large number of trained archaeologists who are working on those sites. Thus Europe continues to surprise us in the richness of its record: so let's now look at some old and new finds that illustrate this.

Shortly before Christmas in 1994, three cavers decided to explore a small opening in the limestone cliffs in the Ardèche region of southern France. Clearing rock falls, they reached a shaft and, descending with a caving ladder, entered a huge chamber, richly adorned with stalactites. Moving on to another large chamber, they started to see fossil animal bones on the floor and, after some time, decided to head back. Quite by chance, the beam of one of their lamps fell on a small red ocher drawing of a mammoth; at that moment they knew they were on the brink of a great discovery. They were astounded at the galleries of hundreds of paintings and engravings in charcoal and red ocher that they and the prehistorians who joined them over the next few weeks were to discover in the cave now named after one of them: Chauvet. About 36,000 years ago, several artists must have walked deep into the cave with flaming torches and squatted down to draw two rhinos locked in combat in charcoal. Just to the left they then outlined the heads of three aurochs (wild cattle), and, in the center, one of them picked out outlines in the rock and drew four beautiful horses' heads. Each of the horse's heads seems to show a different mood or character, as though depicting the passage of time or some inner narrative.