An Evolutionary Paradox for Prosocial Behavior

Evolution and the classification of social behavior

“…In terms of the idealized framework for 2 9 2 games, Social Dilemmas can be changed into Coordination games, or perhaps even into social delights in the right circumstances. Allowing the game or interaction type to co-evolve with behavioral strategies unlocks a novel space of dynamical scenarios (Hashimoto and Kumagi 2003;Worden and Levin 2007;Smead 2014). Alternatively, individuals may be faced with two or more interaction types but not know which game they are playing at a particular time.…”

“…Even in the best case scenario for cooperation, Social Delight, there are potential obstacles related to finite populations and the size of the cooperative payoffs (Forber and Smead 2014). Indeed, the devil is in the details for understanding the evolution of cooperation, and recognizing that some cooperative behavior involves mutual benefit does little to clarify the evolutionary picture.…”

“…That said, it turns out that even in the so-called easy cases for cooperation certain difficulties can arise in the form of spiteForber and Smead (2014).3 Mutually beneficial social behavior is often referred to as ''mutualism'' or as ''by-product mutualism'' in the literature West et al (2007). argue that the term ''mutual benefit'' is better than ''mutualism,'' given the common use of the latter term in ecology to describe cross-specific symbioses.…”

The evolution of cooperation in finite populations with synergistic payoffs

“…Thus, increasing the benefit of cooperative behavior beyond a certain value makes cooperation selectively disadvantageous in a finite population. This is the counterintuitive result that Forber and Smead (2014) call the "spite effect": in the finite-population prisoner's delight, defection is a spiteful behavior because it is costly for the defector to perform but under the right conditions it can nonetheless evolve. This is not the only reason why finite population models pose a problem for the evolution of cooperation.…”

“…This is not the only reason why finite population models pose a problem for the evolution of cooperation. Another reason is what Forber and Smead (2014) call "the nearly neutral effect." To understand how this effect arises, we must first define the concept of selection coefficient.…”