The selection of altruistic behaviour

TL;DR

This paper explores how altruistic behavior can persist in populations through a simple model showing that mixed groups with some altruists can be stable when altruists confer advantages to others.

Contribution

It introduces a model demonstrating the stability of inhomogeneous groups with altruists, highlighting conditions where altruism persists despite individual disadvantages.

Findings

Mixed groups with altruists can be stable under certain conditions.

Presence of altruists provides group-wide advantages.

Altruism can be maintained in populations through group benefits.

Abstract

Altruistic behaviour is disadvantageous for the individual while is advantageous for its group. If the target of the selection is the individual, one would expect the selection process to lead to populations formed by wholly homogeneous groups, made up of either altruistic or egoistic individuals, where the winning choice depends on the balance beetwen group advantage and individual disadvantage. We show in a simple model that populations formed by inhomogeneous groups can be stabilized in some circumstances. We argue that this condition is realized when there is a relative advantage conferred by the presence of a few altruists to all the members of the group.