Cheater-altruist synergy in public goods games

J Theor Biol. 2018 Oct 7:454:231-239. doi: 10.1016/j.jtbi.2018.06.012. Epub 2018 Jun 13.

Abstract

Much research has focused on the deleterious effects of free-riding in public goods games, and a variety of mechanisms that suppress cheating behavior. Here we argue that under certain conditions cheating can be beneficial to the population. In a public goods game, cheaters do not pay for the cost of the public goods, yet they receive the benefit. Although this free-riding harms the entire population in the long run, the success of cheaters may aid the population when there is a common enemy that antagonizes both cooperators and cheaters. Here we study models of the interactions between tumor cells, which play a public goods game, and the immune system. We investigate three population dynamics models of cancer growth combined with a model of effector cell dynamics. We show that under a public good with a limiting benefit, the presence of cheaters aids the tumor in overcoming immune system suppression, and explore the parameter space wherein it occurs. The mechanism of this phenomenon is that a polymorphism of cheaters and altruists optimizes the average growth rate of the tumor, which is what determines whether or not the immune response is overcome. Our results give support for a possible synergy between cooperators and cheaters in ecological public goods games.

Keywords: Cooperation; Immune-cancer dynamics; Public goods games; Volunteer’s dilemma.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Altruism*
  • Cell Communication / immunology*
  • Cell Proliferation
  • Competitive Behavior / physiology
  • Cooperative Behavior
  • Game Theory*
  • Humans
  • Models, Theoretical
  • Neoplasms / immunology
  • Neoplasms / pathology*
  • Population Dynamics
  • Social Behavior
  • Tumor Burden
  • Tumor Escape* / immunology