Introduction
You often look at human history and wonder why different societies develop such astonishingly varied customs, diets, and family structures. You might struggle to understand why some cultures practice infanticide, worship sacred cows, or engage in ritual warfare while others forbid these behaviors.
Marvin Harris answers these puzzles through cultural materialism. The central idea is that human biology, social life, and history are shaped by practical infrastructures, ecological constraints, and the material struggle for survival rather than innate racial superiority or genetic destiny.
The book traces this development across five stages. You explore early hominid origins, the biological realities of race, and the evolution of human diet and sexuality. You then examine how warfare and gender relations shift into state-level hierarchies and religious systems.
- Why did humans abandon hunter-gatherer life for agriculture?
- How did male supremacy and warfare originate?
- What economic pressures created modern world religions?
1. Origins and Cultural Takeoff
In the Beginning
By 4 million years ago, your ancestors already walked erect on two feet. Walking upright freed hominid hands from locomotion, allowing them to evolve into delicate and precise manipulatory forelimbs. Unlike other apes whose feet retained grasping big toes, ancestral apes developed feet suited only for standing, running, and jumping. Their hands became solely responsible for carrying and making tools.
Early australopithecines were primarily scavengers rather than mighty hunters. They relied on natural predators to open tough animal hides. Because their early digging sticks could not pierce thick animal skin and they lacked fangs, australopithecines waited for lions to abandon carcasses. They used sticks and stones to drive off smaller scavengers like vultures and jackals before retreating to the safety of trees.
Between 3 million and 2.5 million years ago, australopithecines achieved a technological breakthrough by making cutting rocks. Nonhuman primates also possess rudimentary cultures consisting of learned traditions passed down across generations through social observation rather than genes. While basic biological capacities are genetic, specific subsistence behaviors are learned traditions unique to specific local groups.
At Koshima, a young female Japanese macaque invented a method to wash sand off sweet potatoes in a brook. This behavior spread until 80 to 90 percent of the animals adopted it. Young Gombe chimpanzees begin termiting at 18 to 22 months old.
Heat and Language
Bipedalism freed hominid hands for tool use and scavenging, while natural selection for thermal regulation during endurance running drove brain enlargement and linguistic takeoff.
The enlargement of the H. erectus brain was driven by selection for neural redundancy to prevent heat stroke during long-distance endurance running. Individual brain cells are highly susceptible to heat stress during prolonged running in the midday sun. Having extra neural connections provided fail-safe thermal tolerance, allowing erectus to run down game until exhaustion while utilizing eccrine sweat glands and bodily nudity for evaporative cooling.
The appearance of the first erectus occurred 1.6 million years ago. Human top speed for short distances is 20 miles an hour. Temperatures in African savanna habitats just before dawn dropped to 40 degrees Fahrenheit.
Tarahumara Indians of northern Mexico hunt deer by chasing them relentlessly for one to two days until the animals fall from exhaustion.
Cultural takeoff is linguistic takeoff, and children spontaneously invent fully grammatical creole languages from rudimentary pidgins using an innate biological blueprint. When diverse populations are forced to communicate via simplified pidgins lacking grammatical rules, the children exposed to it automatically supply complex syntactic rules within a single generation, creating fully formed creoles.
In late nineteenth-century Hawaii, various immigrant groups spoke a rudimentary pidgin, but their children rapidly converted it into Hawaiian creole with complex and consistent grammatical structures.
The elongation of the pharynx is the physiological adaptation that enables humans to produce essential vowel sounds and rapid speech. Human speech requires vowel sounds produced in the pharynx, which is made possible because our upper trachea is positioned lower than in other mammals. This deep throat arrangement creates the evolutionary danger of choking on food, but provides the neural and anatomical substrate necessary for automated speech production and complex syntax.
Keith and Cathy Hayes reared a chimp named Viki who could only utter four words clearly because chimpanzees lack the required pharynx. Each human language uses 50 distinct sounds to build words and sentences.
2. Biology, Race, and Adaptation
Human physical differences like skin color and body shape are evolutionary trade-offs responding to environmental pressures, while racial intelligence gaps stem from environmental deprivation.
Neandertals appeared in the fossil record 100,000 years ago during the onset of continental glaciations. They developed thick, squat bodies following Bergman's rule, massive front teeth for softening animal hides, and heavy browridges to buttress the face against powerful chewing forces. Ralph Solecki discovered pollen grains in Shanidar Cave, Iraq, interpreted by some as floral tributes, though debated as natural depositions. A Neandertal male died in Shanidar Cave, Iraq, 60,000 years ago.
Skin Color and Climate
Human skin color evolved as an evolutionary trade-off between the protective need against ultraviolet radiation and the biological requirement for vitamin D synthesis. High levels of melanin protect skin from sunburn and skin cancers like malignant melanoma in equatorial regions. Conversely, northern latitudes require lighter skin to allow weak sunlight to synthesize vitamin D and prevent deficiency diseases like rickets and osteomalacia.
Almost all of Europe lies north of 42°N latitude, where winter sunlight fails to stimulate vitamin D synthesis. Pioneer cattle herders beginning around 6000 B.C. in northern Europe faced rickets risks due to heavy clothing and lack of marine foods, heavily favoring individuals with fair, translucent skin.
Intelligence and Environment
19th-century scientists like Thomas Huxley claimed whites were intellectually superior because European nations dominated industrialization and commerce. However, history is full of dramatic upendings, such as Germanic tribes destroying Rome or European powers humbling the massive, technologically advanced Chinese empire. Furthermore, colonialism actively crippled regions like Africa and Indonesia by encouraging tribal wars, limiting education, and preventing the development of industrial infrastructures.
Emperor Ch'ien-Lung haughtily rejected a British trade delegation in 1792 because China possessed all things, yet within fifty years, British and European troops humiliated Chinese armies and controlled its seaports. In 1792, China's centralized bureaucracy governed 300 million people under its rule. Nazi starvation attempts in the Warsaw ghetto left residents consuming only 800 calories per day.
Standardized I.Q. test score gaps between races reflect environmental deprivation and systematic repression rather than innate genetic differences in intelligence. While national averages show black Americans scoring lower on I.Q. tests, these tests measure a lack of social preparation, inferior schooling, and broken family environments rather than innate mental capacity. Twin studies attempting to separate heredity from environment are fundamentally flawed because adoption agencies match socioeconomic backgrounds, and white environments can never replicate the unique social experiences and prejudice faced by black children.
Blacks score on average 15 points lower on standardized I.Q. tests compared to whites. Proponents attribute 20 percent of the fifteen-point difference to environmental rather than genetic differences.
The famous Piltdown Man fossil hoax persisted for decades because scientists let their preconceived biases about brain evolution override critical examination. In 1912, fragments of a skull and an apelike jaw found near Piltdown were presented as Dawson's Dawn Man, a missing link matching Darwinian predictions. The big-headed fossil was eagerly accepted by British scholars who believed the large brain must have evolved first to guide the hand. In 1953, fluorine dating and microscopic analysis exposed the find as a deliberate forgery combining a thick human skull with an altered orangutan jaw and a filed chimpanzee tooth.
Charles Dawson dug up skull fragments near Piltdown Commons, and anatomist Smith Woodward presented a plaster reconstruction of Eoanthropus Dawsoni, which was kept under lock and key until Oxford anthropologist J.S. Weiner exposed the file marks in 1953.
3. Diet, Reproduction, and Sexuality
Human appetites, mating systems, and family structures are adaptive responses to ecological resources and labor needs rather than fixed genetic imperatives.
Hunger and Obesity
Obesity is largely a hereditary vulnerability resulting from millions of years of evolution under seasonal food scarcity rather than a personal character defect. Human bodies evolved efficient mechanisms to store excess food energy as depot fat to survive regular periods of hunger and seasonal scarcity.
Modern humans easily get fat because natural selection never had a chance to weed out overeating in an environment of abundant, cheap calories. The internal foodstat operates with high tolerance and fails to prevent gradual weight accumulation over a lifetime.
Anselm Keys's laboratory hunger study showed that volunteers recovering from food deprivation began to gorge themselves on 10,000 calories a day. Angus Barbieri lived on nothing but liquids and vitamins for 382 days, dropping from 472 to 178 pounds. Surveys show 24.2 percent of adult men and 27.1 percent of adult women weighing 20 percent more than recommended.
While humans are born with a few innate taste preferences and aversions, cultural cuisines are shaped by practical solutions for supplying essential nutrients efficiently. Infants possess innate avoidances of bitter, sour, and sharp tastes, which often signal poison, and an innate preference for the sweetness of mother's milk. However, cultural selection easily overrides these aversions as children and adults learn to crave bitter, sour, and spicy foods. Specific food traditions and taboos represent ecological and economic trade-offs, such as utilizing animals for labor and milk rather than meat, or eating insects only when larger animal sources are scarce. The human body must ingest 41 substances as essential nutrients.
The ability of adult humans to digest unfermented milk is a genetic adaptation that spread rapidly in northern European dairying populations to aid calcium absorption. Most humans lose the ability to produce lactase after infancy because mother's milk is only necessary for babies. In the Middle East and India, early dairying populations avoided this by consuming milk fermented into yogurt or cheese, or by getting calcium from leafy greens.
Northern Europeans living in mist-shrouded environments lacked vitamin D and leafy greens, giving a massive reproductive advantage to individuals genetically capable of digesting raw milk to prevent rickets. Milkable animals were first domesticated in the Middle East 12,000 years ago. Over 90 percent of individuals in northern European dairying populations carry the gene for adult lactase production.
Mating and Marriage
Unlike many mammalian and primate species that signal ovulation clearly, human females do not reveal when an egg is ready to be fertilized, creating a three-day window of opportunity out of twenty-eight. While species like rhesus monkeys and common chimpanzees exhibit prominent perineal swellings or odors to signal ovulation and ensure sperm presence, humans and pygmy chimpanzees evolved continuous sexual receptivity to bypass this limitation.
Common chimpanzees develop pink perineal swellings that reach the size of grapefruits as ovulation approaches. Female gelada baboons develop bright necklaces of swellings on their chests. The human female ovarian cycle lasts approximately 28 days, an unfertilized human egg lives for 24 hours, and ejaculated human sperm survives for a maximum of 48 hours.
Incest taboos are products of cultural selection and exchange principles rather than genetic aversion, functioning to enforce alliances between small bands and prevent social disruption. Small foraging bands risked extinction without peaceful ties to neighbors. By exchanging sons, daughters, and siblings in marriage, groups formed vital alliances. The horror surrounding incest reflects the danger of broken exchange bargains, though exceptions occurred among royal elites and ancient commoners.
Keith Hopkins reported that during the first 300 years A.D., Egyptian commoners widely practiced brother-sister marriage as normal, open relationships. Researchers also studied 2,516 total marriages in Israeli kibbutzim in relation to the Westermark theory, including 200 marriages in which both partners were reared in the same kibbutz.
Preindustrial parents have larger families because children historically serve as vital economic contributors who provide labor and eventual old-age security. Children begin performing valuable household and agricultural chores at a very early age, offsetting the costs of their upbringing by adolescence. Because Third World parents lack institutional pensions or social security, they rely entirely on surviving children for support in old age, often overshooting their target family size to account for child mortality.
Mahmood Mamdani found that in Manupur, Punjab, villagers initially resisted family planning until mechanized farming reduced the economic value of child labor and created white-collar opportunities. Javanese boys aged twelve to fourteen contribute 33 hours of economically valuable work per week, while girls aged nine to eleven contribute 38 hours per week. Preventing a population from shrinking requires 2.1 children per woman.
4. Warfare, Gender, and Power
Intensified warfare over scarce resources shapes male dominance and female subordination, while technological shifts like the plow determine political hierarchies.
Warfare and Sexism
Men average 11.6 centimeters taller with greater brawn concentrations in the arms, chest, and shoulders, and pregnancy and lactation temporarily restrict female mobility. Because men held a monopoly over hand-held hunting weapons that could also wound humans, they could be more coercive during disputes.
Among the Agta of the Philippines, some women hunt wild pigs, but in 95 percent of known foraging cases, men specialize in big game.
The intensification of warfare in band-and-village societies is the primary key variable predicting and explaining the political and domestic subordination of women. In societies where warfare is pronounced, male tasks are critical to group survival, and male aggressiveness and combat readiness render female opposition dangerous. Conversely, foraging societies with minimal warfare, such as the !Kung or Mbuti, maintain nearly egalitarian gender roles with high female autonomy.
Brian Hayden and associates tested a sample of 33 hunter-gatherer societies and found an unexpectedly high correlation between low status for females and more deaths due to armed combat.
Band-and-village societies wage war primarily to compete for scarce resources like land, soils, and game rather than from an innate drive for aggression. Cultural selection activates aggressive potentials when population densities rise or resources are depleted. Warfare offers a tempting solution to reduce neighbor density and improve living conditions since fatalities are accepted in exchange for potential resource gains.
Carol and Melvin Ember studied a representative sample of 186 societies and found that nearly 75 percent of preindustrial societies had warfare at least once every two years. Mervyn Meggitt estimated that aggressor groups gained significant land in 75 percent of Mae Enga wars in Papua New Guinea, and among the Yanomami, 33 percent of adult male deaths resulted from armed combat with an overall homicide rate of 166 per 100,000 people per year.
The adoption of ox-drawn plows in agriculture gave men a crucial physical advantage that set off a chain of male monopolies in transport, commerce, writing, and government, depressing women's status. Where ox-drawn plows were required to break hard-packed soils, men used their physical strength advantage to control farming operations. This male specialty expanded into driving wheeled vehicles, dominating trade, keeping records, writing, and holding political and religious offices.
Morgan D. Maclachlan studied an Indian village in Karnataka and noted that a plow weighs about 40 pounds while a pair of oxen exerts a pull of about 180 pounds across twenty miles daily.
The Rise of Chiefs and States
Surplus storable food storage enabled big men to evolve into hereditary chiefs who commanded labor, collected tribute, and erected massive public monuments. When harvest surpluses were stored in central repositories during times of scarcity, people turned to redistributors for food in exchange for specialized labor. This leadership role eventually became a sacred trust passed down through hereditary succession.
Trobriand chiefs displayed towering yam houses and received copious tributes from brothers-in-law, while Cherokee chiefs maintained public granaries to distribute aid and fund expeditions, showing parallel patterns across 12,000 miles between the Trobriand Islands and southeastern U.S. chiefdoms.
The transition from chiefdoms to the first states required population circumscription and storable staple food crops that prevented commoners from fleeing. When populations grew large and were geographically circumscribed by undesirable terrain, commoners could not escape oppressive taxation and conscription. Furthermore, durable crops like wheat or maize allowed elites to secure long-term control over stored surpluses.
Hawaiian chiefdoms developed intensive agriculture and stratified classes, but lacked a storable staple food crop like grain, keeping their pantries empty too often to transition into stable states before Captain James Cook arrived in 1778.
The first states emerged in the Middle East through the combination of intensive irrigation agriculture, fortified settlements, and relentless military expansion. As people settled permanently around wild grains and adopted irrigation in flood-prone river valleys, they became trapped in fixed locations. States utilized managerial know-how and military force to extract labor, conquer neighboring territories, and aggregate defeated populations into a peasant class.
In Sumer between 3500 and 3200 B.C., ziggurats loomed over settlements like Uruk, and leaders like Sargon I eventually conquered all of Mesopotamia and surrounding lands by 2350 B.C.
5. Religion and the Second Earth
Animism, the universal belief in extracorporeal and invisible beings, forms the foundational basis of all distinctly religious thought. Sir Edward Tylor proposed that animism arises from recurrent human experiences such as dreams, trances, shadows, reflections, and the mystery of death, which suggest a soul distinct from the body.
Various societies hold beliefs in multiple souls, such as the Jívaro of Ecuador who have three souls and the Fang of Gabon who recognize seven souls.
Early ecclesiastical religions viewed the relationship between humans and gods as a food exchange cycle.
Just as humans need food to survive, gods were believed to require the spiritual essence of food offerings, leaving the corporeal substance to be redistributed by authorities. In the Babylonian myth of Gilgamesh, gods grew famished during a great flood, and Noah subsequently offered burnt animal sacrifices that produced a sweet savor pleasing to the Lord.
Nonkilling world religions arose during the first millennium B.C. as a reaction against the failures of early states, brutal wars, environmental depletion, and the breakdown of traditional animal-sacrificing redistributive feasts. Charismatic leaders from the Mediterranean to the Ganges challenged ancient ecclesiastical assumptions, condemning priests as ritual killers of people or animals. They taught that gods could not be swayed by material bribes, demanding instead a lifetime of love, kindness, and restraint of appetites, with rewards delivered as heavenly immortality after death rather than earthly goods.
Zoroaster in ancient Iran, Mahavira and Gautama Siddhartha in India, and Jesus of Nazareth all appeared during periods of extreme political instability, colonial misrule, and economic stress.
World religions achieved their eminence not through pure pacifist appeal, but because they provided powerful ideological tools for state expansion, military conquest, and political repression. By promising rewards to the soul in lieu of material rewards on earth, governing classes were freed from the burden of providing wealth and happiness to validate their right to rule. Furthermore, nonkilling religions offered defeated populations the assurance of survival upon capture, smoothing incorporation into empires, while religious doctrines that promised heavenly rewards for the soul motivated soldiers to fight fiercely for the state.
Emperor Constantine I converted to Christianity after seeing a vision in A.D. 312, subsequently using the church to unify the Roman Empire, suppress rivals, and bind citizens to military service obligations.
The Second Earth
The parallel evolution of the state, agriculture, and monumental architecture across geographically isolated regions proves that human societies independently follow predictable developmental sequences under similar material conditions. While extreme diffusionism argues that civilization spread from a single Middle Eastern origin, archaeological evidence demonstrates that the Americas and China underwent remarkably similar evolutionary paths, moving from foragers to plant domestication, permanent villages, warring chiefdoms, and eventually centralized states, entirely independent of Old World contact.
In the Huang He Valley of northern China, people were living in villages and planting domesticated millet at least 8,000 years ago, establishing chiefdoms and states long before any significant direct diffusion from Mesopotamia could have taken place.
The second earth of the Americas was colonized during the last Ice Age by big-game hunters crossing the land bridge of Beringia, who subsequently developed completely distinct agricultural systems based on native American plant species. Because no hominid or great ape fossils exist in the Western Hemisphere, the original Americans were clearly immigrant hunters from Asia. Because these migrants brought no knowledge of Old World crops like wheat or barley, second-earth populations independently domesticated local flora such as maize, amaranth, quinoa, beans, and squash over thousands of years.
It took over 2,000 years of selective breeding to transform teosinte, a wild grass found in Mexican highlands, into fully domesticated maize with cobs and kernels firmly fixed to the cob.
The Inca maintained a sophisticated statecraft and centralized economy using knotted string records.
Administration functioned through three basic levels: villages, districts, and provinces, each managed by appointed officials enforcing laws, collecting taxes, and conscripting labor. Village lands were divided into three parts for householders, the priesthood, and the state, with all public works and stored harvests strictly controlled centrally.
You can trace this administrative structure directly through core practices:
- maintain a chain of command from villages through districts to provinces leading back to Cuzco;
- divide village lands into three parts for householders, priesthood, and state storage;
- send government recruiters directly into villages to conscript labor for public works.
10 Key Ideas
- Bipedalism freed hominid hands for tool use and scavenging, while natural selection for thermal regulation during endurance running drove brain enlargement and linguistic takeoff.
- Human skin color evolved as an evolutionary trade-off between the protective need against ultraviolet radiation and the biological requirement for vitamin D synthesis.
- Obesity is largely a hereditary vulnerability resulting from millions of years of evolution under seasonal food scarcity rather than a personal character defect.
- Preindustrial parents have larger families because children historically serve as vital economic contributors who provide labor and eventual old-age security.
- The intensification of warfare in band-and-village societies is the primary key variable predicting and explaining the political and domestic subordination of women.
- The adoption of ox-drawn plows in agriculture gave men a crucial physical advantage that set off a chain of male monopolies in transport, commerce, writing, and government, depressing women's status.
- Surplus storable food storage enabled big men to evolve into hereditary chiefs who commanded labor, collected tribute, and erected massive public monuments.
- Early ecclesiastical religions viewed the relationship between humans and gods as a food exchange cycle.
- Nonkilling world religions arose during the first millennium B.C. as a reaction against the failures of early states, brutal wars, environmental depletion, and the breakdown of traditional animal-sacrificing redistributive feasts.
- The parallel evolution of the state, agriculture, and monumental architecture across geographically isolated regions proves that human societies independently follow predictable developmental sequences under similar material conditions.