The World Until Yesterday: What Can We Learn from Traditional Societies? (52 page)

Most of the !Kung killings (15 out of 22) were parts of feuds in which one killing led to another and then to yet another over the course of up to 24 years; such cycles of retaliatory killings also characterize traditional war (
Chapters 3
and
4
). Among motives for !Kung killings other than that
one of revenge for a previous killing, adultery is the one most often mentioned. For example, a husband whose wife had slept with another man attacked and wounded the adulterer, who then managed to kill the husband. Another cuckolded husband stabbed and killed his wife with a poisoned arrow, then fled the area and never returned.

As for other small-scale societies, some are less violent than the !Kung (e.g., Aka Pygmies, the Siriono), while others are or were more violent (e.g., the Ache, Yanomamo, Greenland and Iceland Norse). During the time that the Ache were still living in the forest as hunter-gatherers before 1971, violence was the commonest cause of death, exceeding even diseases. More than half of Ache violent deaths were at the hands of non-Ache Paraguayans, but killings of Ache by other Ache still accounted for 22% of Ache deaths. In marked contrast to the pattern of !Kung violence directed exclusively against adult !Kung, most (81%) of Ache homicide victims were children or infants—e.g., children (predominantly girls) killed to accompany a dead adult into the grave, children who were killed or who died of neglect after the death or desertion of their father, or infants killed because they were born separated by only a short birth interval from their next older sibling. Also in contrast to the !Kung, the commonest form of in-group killings of adult Ache was not a spontaneous fight with whatever weapons happened to be at hand, but instead a ritualized and pre-planned fight with clubs specially made for the occasion. As is true for the !Kung, state intervention has greatly decreased levels of violence among the Ache: since they began increasingly living on reservations after 1977 and came under the direct or indirect influence of the Paraguayan state, killings of adult Ache by other Ache have ceased, and Ache killings of their children and infants have decreased.

How do people in traditional societies without state government and police protect themselves against the constant danger of violence? A large part of the answer is that they adopt many forms of constructive paranoia. One widespread rule is to beware of strangers: routinely to attempt to kill or drive off a stranger detected on your territory, because the stranger may have come to scout out your territory or to kill a member of your tribe. Another rule is to beware of the possibility of treachery by supposed allies, or (conversely) to practise pre-emptive treachery against potentially fickle
allies. For instance, a tactic of Yanomamo warfare is to invite people of a neighboring village to come to a feast at one’s own village, and then to kill them when they have set down their weapons and are eating. Don Richardson reports that the Sawi people of southwestern New Guinea honor treachery as an ideal: better than killing an enemy outright is to convince an enemy of your friendship, to invite the enemy many times over the course of months to visit you and partake of your food, and then to watch his terror when you declare, just before killing him, “Tuwi asonai makaerin!” (We have been fattening you with friendship for the slaughter!)

Still another tactic to reduce the risk of attack is that the locations of villages are commonly chosen for the purpose of defense or maintaining a good view over the surroundings. For instance, New Guinea mountain villages are typically located on hilltops, and many late-phase Anasazi settlements in the southwestern United States were in sites accessible only by a ladder that could be pulled up to cut off the entrance. While these locations oblige the inhabitants to carry water for long distances uphill from the river in the valley bottom below, that effort is considered preferable to the risk of being surprised by an attack at a riverside valley location. As population density or as fighting increases, people tend to shift from living in dispersed unprotected huts to aggregating for defense in large palisaded villages.

Groups protect themselves by building a network of alliances with other groups, and individuals ally themselves with other individuals. A function of the constant talking that has struck me in New Guinea, and that has struck other visitors to other traditional societies, is to learn as much as possible about each individual in one’s universe of contact, and to monitor people’s activities constantly. Especially good sources of information are women who were born into one’s own group, and who were then sent in marriage to another group, in the common traditional living pattern termed patrilocal residence (i.e., brides moving to join their husband’s group, rather than new husbands moving to join their wife’s group). Such married women often warn their blood relatives in their natal society that their husbands and other relatives by marriage are planning an attack. Finally, just as endless evening campfire conversations about accidents serve not just to entertain but also to educate children
(and everyone else) about environmental risks, endless conversations about raids and people alert listeners to dangers arising from people, as well as providing gripping entertainment.

Depending on the particular traditional society, diseases collectively rank as either the leading danger to human life (e.g., among the Agta and !Kung, where they accounted respectively for an estimated 50%–86% and 70%–80% of all deaths) or as the second most important danger after violence (e.g., among the Ache, among whom “only” one-quarter of deaths under conditions of forest life were due to illness). It must be added, though, that malnourished people become more susceptible to infection, and that food shortage is thus a contributing factor to many deaths whose cause is recorded as infectious disease.

Among diseases, the relative importance of different categories of disease for traditional peoples varies greatly with lifestyle, geographic location, and age. In general, infectious diseases are most important among infants and young children and remain important at all ages. Parasitic diseases join infectious diseases in importance in childhood. Diseases associated with worm parasites (such as hookworm and tapeworm) and insect-born protozoan parasites (such as malaria and the agent causing sleeping sickness) are more of a problem for peoples of warm tropical climates than for peoples of the Arctic, deserts, and cold mountaintops, where the worms themselves and the protozoa’s insect vectors have difficulty surviving in the environment. Later in life, degenerative diseases of bones, joints, and soft tissue—such as arthritis, osteoarthritis, osteoporosis, bone fractures, and tooth wear—rise in importance. The much more physically demanding lifestyle of traditional peoples than of modern couch potatoes makes the former more susceptible than the latter to such degenerative diseases at a given age. Conspicuously rare or absent among traditional peoples are all of the diseases responsible for most deaths in the First World today: coronary artery disease and other forms of atherosclerosis, stroke and other consequences of hypertension, adult-onset diabe
tes, and most cancers. I shall discuss the reasons for this striking difference between First World and traditional health patterns in
Chapter 11
.

Only within the last two centuries have infectious diseases receded in importance in the First World as causes of human death. The reasons for those recent changes include appreciation of the importance of sanitation; the installation of clean water supplies by state governments, the introduction of vaccination, and other public health measures; the growth of scientific knowledge of microbes as the agents of infectious disease, permitting rational design of effective counter-measures; and the discovery and design of antibiotics. Poor hygiene permitted (and still permits today) the transmission of infectious and parasitic diseases among traditional peoples, who often use the same water supply for drinking, cooking, bathing, and washing, defecate nearby, and do not understand the value of washing one’s hands before handling food.

Just to mention an example of hygiene and disease that impressed me personally, on a trip to Indonesia during which I spent most of each day bird-watching alone on forest trails radiating from a campsite shared with Indonesian colleagues, I was disconcerted to discover that I was experiencing sudden attacks of diarrhea at an hour varying unpredictably from day to day. I racked my brain to figure out what I was doing wrong, and what could account for the variation of the attacks’ timing. Finally, I made the connection. Each day, a wonderfully kind Indonesian colleague, who felt responsible for my well-being, came out from camp and followed my trail of that day until he encountered me, to make sure that I hadn’t had an accident or gotten lost. He handed me some biscuits that he had thoughtfully brought from camp as a snack, chatted with me for a few minutes to satisfy himself that all was well with me, and returned to camp. One evening, I suddenly realized that my diarrhea attack each day began about half an hour after my kind friend had met me and I had eaten his biscuits on that day: if he met me at 10:00
A.M.
, my attack came at 10:30, and if he met me at 2:30
P.M
., it came at 3:00
P.M
. From the next day onwards, I thanked him for his biscuits, disposed of them inconspicuously after he had turned back, and never had any more attacks. The problem had originated with my friend’s handling of the biscuits rather than with the biscuits themselves, of which we kept a supply in their original cellophane
packets at our camp, and which never made me ill when I opened the packet myself. Instead, the cause of the attacks must have been intestinal pathogens transmitted from my friend’s fingers to the biscuits.

The prevalent types of infectious diseases differ strikingly between small populations of nomadic hunter-gatherers and family-level farming societies on the one hand, and large populations of modern and recently Westernized societies plus traditional densely populated Old World farming societies on the other hand. Characteristic diseases of hunter-gatherers are malaria and other arthropod-transmitted fevers, dysentery and other gastrointestinal diseases, respiratory diseases, and skin infections. Lacking among hunter-gatherers, unless they have been recently infected by Western visitors, are the feared infectious diseases of settled populations: diphtheria, flu, measles, mumps, pertussis, rubella, smallpox, and typhoid. Unlike the infectious diseases of hunter-gatherers, which are present chronically or else flare up and down, those diseases of dense populations run in acute epidemics: many people in an area become sick within a short time and quickly either recover or die, then the disease vanishes locally for a year or more.

The reasons why those epidemic diseases could arise and maintain themselves only in large human populations have emerged from epidemiological and microbiological studies of recent decades. Those reasons are that the diseases are efficiently transmitted, have an acute course, confer lifetime immunity on victims who survive, and are confined to the human species. The diseases become transmitted efficiently from a sick person to nearby healthy people by microbes that a patient excretes onto his skin from oozing pustules, that a patient ejects into the air by coughing and sneezing, or that enter nearby water bodies when a patient defecates. Healthy people become infected by touching a patient or an object handled by the patient, breathing in the patient’s exhaled breath, or drinking contaminated water. The disease’s acute course means that, within a few weeks of infection, a patient either dies or recovers. The combination of efficient transmission and acute course means that, within a short time, everybody in a local population has become exposed to the disease and is now either dead or recovered. The lifetime immunity acquired by survivors means that there is no one else alive in the population who could contract the disease until some future year, when a new crop of unexposed
babies has been born. Confinement of the disease to humans means that there is no animal or soil reservoir in which the disease could maintain itself: it dies out locally and cannot come back until an infection spreads again from a distant source. All of those features in combination mean that these infectious diseases are restricted to large human populations, sufficiently numerous that the disease can sustain itself within the population by moving constantly from one area to another, locally dying out but still surviving in a more distant part of the population. For measles the minimum necessary population size is known to be a few hundred thousand people. Hence the diseases can be summarized as “acute immunizing crowd epidemic infectious diseases of humans”—or, for short, crowd diseases.

The crowd diseases could not have existed before the origins of agriculture around 11,000 years ago. Only with the explosive population growth made possible by agriculture did human populations reach the high numbers required to sustain our crowd diseases. The adoption of agriculture enabled formerly nomadic hunter-gatherers to settle down in crowded and unsanitary permanent villages, connected by trade with other villages, and providing ideal conditions for the rapid transmission of microbes. Recent studies by molecular biologists have demonstrated that the microbes responsible for many and probably most of the crowd diseases now confined to humans arose from crowd diseases of our domestic animals such as pigs and cattle, with which we came into regular close contact ideal for animal-to-human microbe transfer only upon the beginnings of animal domestication around 11,000 years ago.

Of course, the absence of crowd diseases from small populations of hunter-gatherers does not mean that hunter-gatherers are free from infectious diseases. They do have infectious diseases, but their diseases are different from the crowd diseases in four respects. First, the microbes causing their diseases are not confined to the human species but are shared with animals (such as the agent of yellow fever, shared with monkeys) or else capable of surviving in soil (such as the agents causing botulism and tetanus). Second, many of the diseases are not acute but chronic, such as leprosy and yaws. Third, some of the diseases are transmitted inefficiently between people, leprosy and yaws again being examples. Finally, most of the diseases do not confer permanent immunity: a person who has recovered
from one bout of a disease can contract the same disease again. These four facts mean that these diseases can maintain themselves in small human populations, infecting and re-infecting victims from animal and soil reservoirs and from chronically sick people.