Social structure in 2D

Agents wander a plaza and contest status whenever they meet: the stronger one usually wins, and each win or loss shifts status. A hierarchy can emerge on its own. Click an agent to select it, drag to move it; lines flash on every contest.

Society

Population

Decisiveness of contests (eta)

Mobility (walking speed)

Contact radius

Institutions

Status decay (forgetting)

Redistribution (welfare)

Inherited privilege (elite families)

Generational turnover

Presets

Intervene

Click an agent to select it.

Live readouts

History

Hierarchy indexRank persistenceGini

Status distribution

Model: P(i beats j) = 1 / (1 + exp(-eta (E_i - E_j))), winner +1 and loser -1 status (Bonabeau, Theraulaz and Deneubourg 1995). Hierarchy index = mean |2P - 1| over all pairs (1 = every contest predictable). Rank persistence = Spearman correlation of status with 10 s ago.