Individualistic attitudes in iterative Prisoner’s Dilemma undermine evolutionary fitness and may drive cooperative human players to extinction

Humans perform inarguably the richest plethora of prosocial behaviors in the animal kingdom. Prosocial behaviors such as interpersonal cooperation and altruistic punishment are important for understanding how humans navigate their social environment. The success and failure of strategies human players device have implications for determining their long-term socio-economic/evolutionary fitness. Following the footsteps of Press and Dyson’s (2012), I implemented their evolutionary game theoretic models developed for the Iterated Prisoner’s Dilemma (a behavioral economic probe of interpersonal cooperation) and analysed human choice behavior in the Ultimatum Game (a behavioral economic probe of altruistic punishment) involving 50 human participants versus computerized opponents with prosocial or individualistic social value orientation. Although the results indicate that it is more likely to break cycles of mutual defection in ecosystems in which humans interact with individualistic opponents, analysis of social-economic fitness at the Markov stationary states suggested that this comes at an evolutionary cost. Overall, human players acted in a significantly more cooperative manner than their opponents, but they failed to overcome extortion from individualistic agents, risking “extinction” in 70% of the cases. These findings demonstrate human players might be short-sighted and social interactive decision strategies they device while adjusting to different types of opponents may not be optimal in the long run. ### Competing Interest Statement The authors have declared no competing interest.