Psychology › Social psychology › Group behavior: in-groups, crowds and bystanders
In-group bias and social identity (Tajfel)
1971· Finding or experiment
Well replicatedStrong, repeated evidence.
People favor members of their own group, even when the groups are arbitrary and meaningless.
See it on the Psychology map →What it says
In 1970–71 Henri Tajfel, a Polish-born Holocaust survivor working in Bristol, England, sorted schoolboys into groups by trivial criteria, such as preferring paintings by Klee or Kandinsky. Asked to divide points worth money among anonymous boys, they favored their own group, sometimes giving up gains just to beat the other group. With John Turner he developed social identity theory (1979): part of our self-esteem comes from the groups we belong to.
Why it matters
It shows favoritism can arise without any history of conflict, helping explain team loyalty, office factions, partisan politics and discrimination.
The evidence
The 'minimal group' result has been replicated widely across ages and countries; a 2014 meta-analysis found people cooperate more with in-group members in economic games.
Open questions
Researchers debate how often favoring 'us' becomes hostility toward 'them,' and why some groups coexist peacefully while others clash.
Connections (2)
▸Evolutionary psychology proposes an origin for In-group bias and social identity (Tajfel)Mixed evidence
The connection
Evolutionary psychologists argue that for most of human history survival depended on small cooperative bands, so minds evolved to trust and help fellow members and stay wary of outsiders. On this view, favoring an arbitrary team in Tajfel's experiments reflects a quick 'us versus them' instinct firing on minimal cues.
Who showed it and when
Developed from the 1990s by Leda Cosmides, John Tooby and others; a 2001 study with Robert Kurzban suggested people track coalitions, not just race.
How solid is it?
In-group favoritism appears early in childhood and across cultures, and coalition cues can override racial categorization. But the evolutionary origin is inferred, not directly observed.
Open questions
Critics say culture and learning could explain the same patterns, and that 'just-so' stories about ancestral life are hard to test.
▸In-group bias and social identity (Tajfel) is a basic force in Group behavior: in-groups, crowds and bystandersWell replicated
The connection
In-group favoritism is the starting point for much group behavior: team loyalty, rivalries, office factions and partisan politics. Once people identify with a group, they trust, help and forgive members more readily and judge outsiders more harshly, which can escalate when groups compete for resources.
Who showed it and when
Tajfel's minimal group studies in Bristol, 1970–71; Muzafer Sherif's 1954 Robbers Cave summer camp study in Oklahoma, where rival boys' groups clashed.
The evidence
Minimal group results replicate widely, and a 2014 meta-analysis of economic games confirmed in-group cooperation. Robbers Cave has been criticized for staging.
Open questions
Favoring 'us' does not automatically mean hostility toward 'them'; what tips favoritism into conflict is still studied.