Humans clearly sort themselves into groups and often favor their own. But “tribal” is a slippery word, and the deep past can’t tell us how anyone felt about belonging. Chimpanzees, among our close living relatives, defend their communities and sometimes kill outsiders. In one 2014 survey, the bonobo records contained only one suspected killing. Before writing, some of the best clues to belonging beyond a small band are objects that traveled: stone moved tens of kilometers in Kenya about 320,000 years ago, and ostrich-eggshell beads that reached the highlands of Lesotho from far away, starting about 33,000 years ago. In a 1970 report, psychologist Henri Tajfel described teenage boys, sorted into meaningless groups, who tilted rewards toward their own side while also trying to be fair. How much of this comes from biology and how much from culture is still argued.
How to read the labels on this page: [Documented] means the evidence shows it directly. [Strongly supported] means strong sources agree. [Plausible] means the evidence allows it but doesn’t prove it. [Disputed] means qualified experts disagree. [Unknown] means the evidence can’t answer the question.
What does “tribal” even mean?
In everyday talk, “tribal” means fierce loyalty to your side, whether that’s a team, a party or a fandom. The word has a heavier history. Cambridge anthropologist David Sneath explains that the modern idea of “the tribe” took shape during European and American colonial expansion, as a label for peoples the colonists considered “primitive.” Nineteenth-century scholars treated “tribal society” as an early stage that “civilization” had supposedly left behind (Sneath 2016). Under colonial “indirect rule” in Tanganyika, administrators assumed every African belonged to a tribe and governed through tribes. Anthropologist Elizabeth Colson noted that the Hausa state of Kano outstripped many medieval European kingdoms, yet the Hausa were still called a “tribe.” In her words, the label “signals something about political domination.” Western-trained social and cultural anthropologists have since largely dropped “tribe” as a tool for analysis. [Documented as Sneath’s account of his field]
The word hasn’t disappeared, though. In the United States, a federally recognized tribe has a government-to-government relationship with the United States and inherent rights of self-government (Bureau of Indian Affairs). So this page says “group identity” for the general human habit and uses each people’s own name when it talks about a people.
Do other primates have an “us”?
Humans and the African great apes (chimpanzees, bonobos and gorillas) share evolutionary ancestors (Smithsonian Human Origins). [Strongly supported] Apes can hint at where human group life came from, but they aren’t our ancestors.
In 2014, a team of 30 researchers pooled five decades of records from 18 chimpanzee communities and 4 bonobo communities (Wilson et al. 2014). They counted 152 killings by chimpanzees in 15 communities: 58 seen directly, 41 inferred and 53 suspected. Two-thirds (66%) were attacks across community lines, and attackers outnumbered victims by a median of 8 to 1. Bonobos had one suspected killing. [Documented for the counts] The authors conclude that their results fit the idea that killing pays off for attackers, through more territory, food or mates, and don’t fit the rival idea that human disturbance causes it. [Plausible for the explanation] With bonobos so different, there’s no single ape starting point for “us versus them.”
Researchers Richard McElreath, Robert Boyd and Peter Richerson note that, unlike other primates, human populations are often split into ethnic groups. People claim membership in them, and they’re marked by seemingly arbitrary signals like dress or dialect (McElreath et al. 2003, p. 122). [Documented as their starting observation]
What can stones and beads tell us about belonging before writing?
This collection uses a ladder of inference for the deep past. First, what does the object show? Then, what did people do with it? Meaning, motive, feeling and identity sit on the top rung, and objects alone can’t reach it.
Obsidian in Kenya. A Smithsonian–National Museums of Kenya project reported non-local obsidian at Middle Stone Age sites in the Olorgesailie Basin, including sites about 320,000 years old. The research team’s account of the chemical matching places sources in several directions, at least 25–95 kilometers away in straight-line distance. [Documented as the team’s report] The researchers interpret this movement as evidence of exchange networks. [Plausible] Chemical matching shows where stone came from. By itself, it doesn’t record who carried it, whether it changed hands, or how anyone understood group membership.
Eggshell beads in Lesotho. Ostrich eggshell picks up the chemical signature of the rocks where the bird lived, a bit like a postmark (analogy, not evidence). In 2020, Brian A. Stewart and colleagues measured strontium isotopes in 27 ostrich-eggshell beads from two rock shelters in the Lesotho highlands, Sehonghong and Melikane (Stewart et al. 2020). None matched the basalt that caps the highlands, and 21 of the 27 (78%) could not have come from ostriches living in highland Lesotho. The oldest, a non-local bead, dates to about 33,000 years ago. [Documented for the measurements and dates] The authors conclude the eggs came from ostriches living well outside the highlands, and that the beads arrived through social networks linking regions at least several hundred kilometers apart. [Plausible for the networks]
The authors warn against culturally linking the earliest bead makers with 20th-century Kalahari San. They also suggest these beads may first have served “not to differentiate individuals and groups but rather to bind them together.” So these beads may have worked more like bridges between groups than walls around them. [Plausible] What anyone felt about “us” 33,000 years ago: [Unknown]
What happened when boys were split into meaningless groups?
Henri Tajfel was born to a Jewish family in Włocławek, Poland, on June 22, 1919. Called up into the French army during World War II, he was captured by German forces. His captors never learned he was Jewish, and he survived in prisoner-of-war camps. When he came home, nearly all his friends and family were dead. He helped orphans and camp survivors rebuild their lives, then studied psychology. In 1967 he became chair of social psychology at the University of Bristol, and he died in 1982 (Reicher, EASP). [Strongly supported]
At Bristol he ran the experiments that made him famous (Tajfel 1970). Earlier studies, such as Muzafer Sherif’s, had needed days of intense competition before groups discriminated against each other (p. 102). Tajfel’s team set out to test the effect of the category alone (p. 99). His subjects were 64 boys, aged 14 and 15, from a state school in a Bristol suburb, who already knew one another. They estimated clusters of flashed dots. Some were then told they were “overestimators” or “underestimators,” but they’d actually been assigned at random (p. 99). Working alone, each boy handed out rewards and penalties in real money to other boys identified only by code number, never to himself. A large majority gave more to their own group (p. 101). In a second study, the groups were supposedly based on liking paintings by Paul Klee or Wassily Kandinsky, and were again random. Boys often chose to beat the other group even when that meant less money for everyone, their own group included. Fairness pulled too: Tajfel described most choices as a “compromise between fairness and favoring one’s own group” (p. 102). [Documented]
Analogy (not evidence): imagine a coin toss splitting your class into red and blue teams. A few minutes later, you’re rooting for red.
Tajfel called it a “crude oversimplification” to explain this with universal drives such as “aggression toward the outsider” (p. 102). He pointed to learned social norms instead. With John Turner, he developed social identity theory, set out in a 1979 chapter. It says people sometimes act as individuals and sometimes as group members, and that, as group members, they want their group to compare well with others (Brown 2020, author copy p. 4). Psychologist Steve Reicher says Tajfel meant it mainly as a theory of how disadvantaged groups push for change, and that the minimal-group studies were often “taken out of context” (Reicher, EASP). Rupert Brown, who trained under Tajfel, credits the theory’s “generative power” but finds it hard to test and nearly silent on emotion and hatred (Brown 2020, author copy pp. 7, 16–17). [Disputed as a full explanation of prejudice]
Tajfel’s record includes harm, too. In 2019, researchers Young and Hegarty documented his bullying and sexual harassment of many students and colleagues. The editors of the British Journal of Social Psychology called that behavior deplorable (Gibson & Smith 2020).
Is group loyalty built into biology, or built by culture?
Three serious positions, none settled [Disputed]:
- Cooperation as a force of nature. In 1902 Peter Kropotkin (1842–1921) called mutual aid “one of the chief factors of evolution,” “as much a law of animal life as mutual struggle,” and “most probably” the more important of the two (Kropotkin 1902). Our pages on group life and on violence and cooperation tell that story.
- Markers help people find others who share their rules. In a mathematical model by McElreath, Boyd and Richerson, dress or dialect signals persist because they help people find others who share their expectations about how to behave (McElreath et al. 2003, p. 123). It’s a model, not a dig. [Plausible]
- Culture first, then genes. Richerson and colleagues argue that groups with better-working shared rules outcompeted others. Their “tribal social instincts” hypothesis holds that culture led and genes followed (Richerson et al. 2016, §2.2). Critics in the same journal issue call the evidence “patchy” (Mace & Silva 2016) or say it fails to support the idea (Lamba 2016). [Disputed]
How we know
What evidence exists: stone traced to its sources, chemical fingerprints in eggshell, five decades of field records on wild apes, laboratory experiments and mathematical models. None of them records a feeling of belonging from before writing.
Whose voices are missing: everyone who carried obsidian in Kenya or strung beads in Lesotho. Tajfel’s subjects are anonymous, and all were boys. Psychology samples are narrow in general: one review found that 96% of subjects in top psychology journals from 2003 to 2007 came from Western industrialized countries, home to about 12% of the world’s population (Henrich et al. 2010, §2.1). The sources used here include no statements from Kenyan or Basotho heritage authorities, or from San communities today.
How power shaped the record: who got called a “tribe” and who got called a “nation” tracked who held power (Sneath 2016). And famous findings travel without their fine print, as Reicher notes of the minimal-group studies.
Then vs. now
- Before writing: stone traveled tens of kilometers. [Documented] Beads traveled, by one team’s estimate, hundreds of kilometers through networks linking distant regions. [Plausible] Who counted as “us,” and how it felt: [Unknown]
- Nineteenth and early twentieth centuries: Lewis Henry Morgan ranked societies from “savagery” through “barbarism” to “civilisation,” and colonial governments sorted people into tribes to rule them (Sneath 2016). Even Kropotkin, arguing for cooperation, titled chapters “Mutual Aid among Savages” and “among the Barbarians” (Kropotkin 1902).
- Now: Western-trained social and cultural anthropologists mostly treat “tribe” as a word to study, not a tool for analysis. Experiments show people can favor their own side on the flimsiest grounds while also caring about fairness, mostly in Western samples. Whether culture or genes did more to build group loyalty is [Disputed].
A short timeline
- Millions of years ago: humans and the African great apes shared ancestors; living apes are relatives, not ancestors of living humans.
- About 320,000 years ago: obsidian moved at least 25–95 km at Olorgesailie, Kenya.
- About 33,000 years ago: oldest non-local ostrich-eggshell bead at Sehonghong, Lesotho.
- 1970: Tajfel describes the minimal-group experiments in Scientific American.