how do animals even trust each other

Many animals form mutually beneficial relationships, yet each participant could gain by cheating, creating a trust problem that evolution must solve.

Game theorists and evolutionary biologists use the prisoner’s dilemma to model how cooperation and betrayal can emerge among organisms that interact repeatedly.

Mutualistic partners, such as cleaning species and their hosts, face a choice between cooperation and cheating in each encounter.

Robert Axelrod and W. D. Hamilton simulated competing strategies in repeated prisoner’s dilemma games to see which behaviors thrive under evolutionary style pressure.

Many species form long term exchanges that benefit both sides, creating stable partnerships between animals, insects, and plants.

Predators, prey, parasites, and hosts interact in ways that are not mutualistic, reminding biologists that cooperation is only one slice of ecological relationships.