Why Class Formation Occurs in Humans but Not among Other Primates : A Primate Coalitions Model.

Area of Science:

• Sociobiology
• Evolutionary Game Theory
• Behavioral Economics

Background:

• Human societies commonly display distinct class structures (elite, middle, bottom).
• Animal societies typically form simpler dominance hierarchies without organized oppression.
• Previous models explored primate coalitions but did not fully explain human class formation.

Purpose of the Study:

• To extend a model of primate coalitions to explain the emergence of class structures in human societies.
• To identify conditions under which a division into distinct social classes is inevitable.
• To analyze the dynamics and stability of these predicted class structures.

Main Methods:

• Development and analysis of a mathematical model based on primate coalition dynamics.
• Incorporation of factors such as resource exploitability, tradability, and group mobility.
• Simulation of payoff structures and coalition formation across different social strata.

Main Results:

• A class division into a bottom and upper class is an inevitable outcome under specific conditions (tradable resources, restricted mobility).
• The model predicts a large bottom class with minimal payoff, and an upper class that may subdivide into middle classes and an elite.
• The bottom class is generally unable to form counter-coalitions unless supported by dissatisfied middle-class members.

Conclusions:

• The model provides a parsimonious explanation for the prevalence of class structures in food-producing societies versus their absence in nomadic hunter-gatherers.
• Social stratification, characterized by a bottom class and an upper class, is a predictable outcome of evolutionary and economic pressures.
• The stability of class structures can be maintained by managing payoffs to prevent unified opposition from lower strata.