Rational Group Decision Making. A random field Ising model at T=0

TL;DR

This paper models group decision making using a modified random field Ising model at zero temperature, revealing how social pressure, individual biases, and conflicts influence consensus, polarization, and compromise.

Contribution

It introduces a novel application of a zero-temperature Ising model with quenched fields to analyze group decision dynamics and social influence effects.

Findings

Small social pressure can drastically alter group polarization.

Individual biases expand the spectrum of collective choices.

Conflict reduces group polarization.

Abstract

A modified version of a finite random field Ising ferromagnetic model in an external magnetic field at zero temperature is presented to describe group decision making. Fields may have a non-zero average. A postulate of minimum inter-individual conflicts is assumed. Interactions then produce a group polarization along one very choice which is however randomly selected. A small external social pressure is shown to have a drastic effect on the polarization. Individual bias related to personal backgrounds, cultural values and past experiences are introduced via quenched local competing fields. They are shown to be instrumental in generating a larger spectrum of collective new choices beyond initial ones. In particular, compromise is found to result from the existence of individual competing bias. Conflict is shown to weaken group polarization. The model yields new psycho-sociological insights about consensus and compromise in groups.