The role of behavioural plasticity in finite vs infinite populations

TL;DR

This paper investigates how behavioural plasticity, or incompetence, influences the evolution of strategies in finite and infinite populations within evolutionary game theory, revealing conditions that can promote cooperation.

Contribution

It introduces the concept of behavioural plasticity in population dynamics, showing how heterogeneity can alter evolutionary outcomes and promote cooperation in classic games.

Findings

Behavioural plasticity can make dominated strategies desirable.

Plasticity eases conditions for fixation in infinite populations.

Cooperation can be promoted through heterogeneity in strategies.

Abstract

Evolutionary game theory has proven to be an elegant framework providing many fruitful insights in population dynamics and human behaviour. Here, we focus on the aspect of behavioural plasticity and its effect on the evolution of populations. We consider games with only two strategies in both well-mixed infinite and finite populations settings. We assume that individuals might exhibit behavioural plasticity referred to as incompetence of players. We study the effect of such heterogeneity on the outcome of local interactions and, ultimately, on global competition. For instance, a strategy that was dominated before can become desirable from the selection perspective when behavioural plasticity is taken into account. Furthermore, it can ease conditions for a successful fixation in infinite populations' invasions. We demonstrate our findings on the examples of Prisoners' Dilemma and Snowdrift game, where we define conditions under which cooperation can be promoted.