Minimal Group Tribalism Lab: Why Humans Form Us vs Them

Active Population Foraging Arena

40 Autonomous Agents with Mutual Defense & Resource Buffers

Tick: 0 Alive: 40/40 Predators: 3

Neutral Group Teal Group Amber Predator Food Cache

Neutral State: No Tribes Assigned

In-Group Share Ratio

0.74

Out-Group Share Ratio

0.26

Max Differentiation Gap

+32

Clustering Coeff

0.81

Band Survival Rate

88.5%

Solitary Survival Rate

4.2%

1. Arbitrary Division Trigger (Tajfel 1971)

Flip an arbitrary coin or assign trivial dots to watch immediate in-group favoritism and out-group defense clustering emerge.

2. Payoff Matrix Allocation Strategy

Maximum Differentiation (MD) — Tajfel Discovery

Agents accept lower absolute payoff just to maximize the relative gap over the out-group (Us: 19, Them: 7).

Maximum In-Group Profit (MIP)

Agents purely seek the highest payoff for their own tribe, regardless of the rival's reward (Us: 25, Them: 21).

Maximum Joint Payoff (MJP) — Global Harmony

Agents cooperate to maximize overall societal resources across both groups (Us: 25, Them: 25).

3. Ancestral Threat & Ecological Levers

Predator / Threat Pressure 70%

Higher pressure forces tight mutual-defense clusters; isolated agents are hunted rapidly.

Resource Scarcity 65%

When food patches shrink, in-group sharing shields kin while starving out-groups.

In-Group Bias Weight 0.82

Probability of directing scarce food buffers strictly to fellow tribe members.

4. Historical Presets

Why "To Be Alone Was To Be Dead": The Dual Pillars of Human Tribalism

Insights synthesized from Henri Tajfel (1971), John Tooby & Leda Cosmides, and ancestral anthropological demographics.

1. The Minimal Group Paradigm (Tajfel, 1971)

British social psychologist Henri Tajfel discovered that creating arbitrary, meaningless categories—like tossing a coin or guessing dot counts—was sufficient to produce immediate in-group favoritism. Crucially, subjects repeatedly selected the Maximum Differentiation (MD) option: sacrificing higher rewards for their own team just to ensure the out-group received far less.

2. Evolutionary Life-Support System

For over 99% of hominid history, an isolated human was virtually guaranteed death from Pleistocene megafauna, exposure, or rival bands. The band was not an elective club; it was an externalized immune system and calorie battery. Solitary survival approached 4%, creating immense evolutionary selection pressure for loyalty badges.

3. Modern Super-Tribes & Dunbar Limits

While human neocortex limits natural intimate trust to ~150 individuals (Dunbar's number), cultural evolution invented shared symbols, flags, anthems, and arbitrary creed tests. These super-normal stimuli hijack our ancestral band circuitry, scaling cooperation (and conflict) to millions.